1.A.8 The Major Intrinsic Protein (MIP) Family
The Major Intrinsic Protein (MIP) of the human lens of the eye (Aqp0), after which the MIP family was named, represents about 60% of the protein in the lens cell. In the native form, it is an aquaporin, but during lens development, it becomes proteolytically truncated. The channel, which normally houses 6-9 water molecules, becomes constricted so only three remain, and these are trapped in a closed conformation (Gonen et al., 2004a,b). These truncated tetramers form intercellular adhesive junctions (head to head), yielding a crystalline array that mediates lens formation with cells tightly packed as required to form a clear lens (Gonen and Walz, 2006). Lipids crystallize with the protein (Gonen et al., 2005). Ion channel activity has been shown for Aquaporins 0, 1, and 6, Drosophila Big Brain and plant Nodulin-26 (Yool and Campbell, 2012). Roles of aquaporins in human cancer have been reviewed (Pareek et al. 2013) as have their folding pathways (Klein et al. 2015). AQPs may act as transmembrane osmosensors in red cells, secretory granules and microorganisms (Hill and Shachar-Hill 2015). MIP superfamly proteins and variations of their selectivity filters have been reviewed (Verma et al. 2015). Their evolution has been discussed (Ishibashi et al. 2017).
The MIP family is large and diverse, possessing thousands of members that form transmembrane channels. These channel proteins function in water, small carbohydrate (e.g., glycerol), urea, NH3, CO2, H2O2 and ion transport by energy-independent mechanisms. For example, the glycerol channel, FPS1p of Saccharomyces cerevisiae mediates uptake of arsenite and antimonite (Wysocki et al., 2001). Ion permeability appears to occur through a pathway different than that used for water/glycerol transport and may involve a channel at the 4 subunit interface rather than the channels through the subunits (Saparov et al., 2001). MIP family members are found ubiquitously in bacteria, archaea and eukaryotes. Phylogenetic clustering of the proteins is largely according to phylum of the organisms of origin, but one or more clusters are observed for each phylogenetic kingdom (plants, animals, yeast, bacteria and archaea) (Park and Saier, 1996). MIPs are classified into five subfamilies in higher plants, including
plasma membrane (PIPs), tonoplast (TIPs), NOD26-like (NIPs), small basic (SIPs) and unclassified X
(XIPs) intrinsic proteins. One of the plant clusters includes only tonoplast (TIP) proteins, while another includes plasma membrane (PIP) proteins (de Paula Santos Martins et al. 2015).
The known aquaporins cluster loosely together as do the known glycerol facilitators. MIP family proteins are believed to form aqueous pores that selectively allow passive transport of their solute(s) across the membrane with minimal apparent recognition. Aquaporins selectively transport water (but not glycerol) while glycerol facilitators selectively transport glycerol but not water. Some aquaporins can transport NH3 and CO2. Glycerol facilitators function as solute nonspecific channels, and may transport glycerol, dihydroxyacetone, propanediol, urea and other small neutral molecules in physiologically important processes. Some members of the family, including the yeast Fps1 protein (TC #1.A.8.5.1) and tobacco NtTIPa (TC #1.A.8.10.2) may transport both water and small solutes.
Calamita et al. 2018 review the expression, regulation and physiological roles of AQPs in adipose tissue, liver and endocrine pancreas that are involved in energy metabolism. The review also summarizes the involvement of AQPs in metabolic disorders, such as obesity, diabetes and liver diseases. Challenges and recent advances related to pharmacological modulation of AQPs expression and function to control and treat metabolic diseases are discussed (Calamita et al. 2018).
Zardoya and Villalba (2001) have conducted phylogenetic analyses of the MIP family, analyzing 153 homologues. They divided the proteins into six major 'paralogous' groups: (1) GLPs, or glycerol-transporting channel proteins, which include mammalian AQP3, AQP7, and AQP9, several nematode paralogues, a yeast paralogue, and Escherichia coli GLP; (2) AQPs, or aquaporins, which include metazoan AQP0, AQP1, AQP2, AQP4, AQP5, and AQP6; (3) PIPs, or plasma membrane intrinsic proteins of plants, which include PIP1 and PIP2; (4) TIPs, or tonoplast intrinsic proteins of plants, which include αTIP, γTIP, and δTIP; (5) NODs, or nodulins of plants; and (6) AQP8s, or metazoan aquaporin 8 proteins. Of these groups, AQPs, PIPs, and TIPs cluster together as noted above.
In agreement with their divergent sequences, human AQP1-9 have very different physiological functions. They are involved in (1) nephrogenic diabetes insipidus, (2) brain water balance and hearing and (3) salivary secretion (Li and Verkman, 2001). Bacterial homologues also have diverse functions. Two proteins in E. coli function as water and glycerol transporters, respectively. Lactobacillus plantarum has 6 homologues, some of which transport water, glycerol and dihydroxyacetone, and some which transporter these compounds as well as D,L-lactic acid (Bienert et al. 2013). The pH sensitivities of Aqp0 channels in lenses of tetraploid and diploid teleosts have been reported (Chauvigné et al. 2015).
Several reports of MIP family proteins transporting ions may or may not be physiologically significant. For example, the influx of arsenite and antimonite via the Fps1 protein into yeast cells is well documented (Wysocki et al., 2001). Similarly, these compounds are taken up via aquaporins in Leishmania (Gourbal et al., 2004). Moreover, AQP6 of renal epithelia have been reported to transport anions at low pH (Yasui et al., 1999). Demonstration of the involvement of the cyanobacterial channel protein (TC #1.A.8.4.1) in copper homeostasis suggests that it may transport Cu2+. Finally, Yang et al. (2005) showed that arsenite exists the Mesorhizobium meliloti cell by downhill movement through AqpS (1.A.8.15.1). The physiological functions of many MIP family proteins are unknown.
MIP family channels consist of homotetramers (e.g., GlpF of E. coli; TC #1.A.8.1.1, AqpZ of E. coli; TC #1.A.8.3.1, and MIP or Aqp0 of Bos taurus; TC #1.A.8.8.1). Each subunit spans the membrane six times as putative α-helices and arose from a 3-spanner-encoding genetic element by a tandem, intragenic duplication event. The two halves of the proteins are therefore of opposite orientation in the membrane. However, a well-conserved region between TMSs 2 and 3 and TMSs 5 and 6 dip into the membrane, each loop forming a half TMS.
Several MIPs within all domains of life have been shown to facilitate the diffusion of reduced and non-charged species of the metalloids silicon, boron, arsenic and antimony (Bienert et al., 2008). Metalloids encompass a group of biologically important elements ranging from the essential to the highly toxic. Consequently, all organisms require efficient membrane transport systems to control the exchange of metalloids with the environment. Recent genetic evidence has demonstrated a crucial role for specific MIPs in metalloid homeostasis (Bienert et al., 2008).
The crystal structure of the glycerol facilitator of E. coli was solved at 2.2 Å resolution (Fu et al., 2000). Glycerol molecules line up in single file within the amphipathic channel. In the narrow selectivity filter of the channel, the glycerol alkyl backbone is wedged against a hydrophobic corner, and successive hydroxyl groups form hydrogen bonds with a pair of acceptor and donor atoms. The two conserved D-P-A motifs in the loops between TMSs 2 and 3 and TMSs 5 and 6 form the interface between the two duplicated halves of each subunit. Thus each half of the protein forms 3.5 TMSs surrounding the channel. The structure explains why GlpF is selectively permeable to straight chain carbohydrates, and why water and ions are excluded. Aquaporin-1 (AQP1) and the bacterial glycerol facilitator, GlpF can transport O2, CO2, NH3, glycerol, urea, and water to varying degrees. For small solutes permeating through AQP1, a remarkable anticorrelation between permeability and solute hydrophobicity was observed whereas the opposite trend was observed for permeation through the membrane (Hub and Groot, 2008). AQP1 is thus a selective filter for small polar solutes, whereas GlpF is highly permeable to small solutes and less permeable to larger solutes.
Aquaporin-1 (Aqp1) from the human red blood cell has been solved by x-ray crystallography to 3.8 Å resolution (Murata et al., 2000). The aqueous pathway is lined with conserved hydrophobic residues that permit rapid water transport. Water selectivity is due to a constriction of the inner pore diameter to about 3 Å over the span of a single residue, superficially similar to that in the glycerol facilitator of E. coli.
AqpZ, a homotetramer (tAqpZ) of four water-conducting channels that facilitate rapid water movements across the plasma membrane of E. coli, has been solved to 3.2 Å resolution. All channel-lining residues in the four monomeric channels are found orientated in nearly identical positions with one marked exception at the narrowest channel constriction, where the side chain of a conserved Arg-189 adopts two distinct conformational orientations. In one of the four monomers, the guanidino group of Arg-189 points toward the periplasmic vestibule, opening up the constriction to accommodate the binding of a water molecule through a tridentate H-bond. In the other three monomers, the Arg-189 guanidino group bends over to form an H-bond with carbonyl oxygen of Thr-183 occluding the channel. Therefore, the tAqpZ structure reveals two distinct Arg-189 conformations associated with water permeation through the channel constrictions. Alternating between the two Arg-189 conformations disrupts continuous flow of water, thus regulating the open probability of the water pore. Further, the difference in Arg-189 displacements is correlated with a strong electron density found between the first transmembrane helices of two open channels, suggesting that the observed Arg-189 conformations are stabilized by asymmetrical subunit interactions in tAqpZ (Jiang et al., 2006).
The 3-D structures of the open and closed forms of plant aquaporins, PIP1 and PIP2, have been solved (Törnroth-Horsefield et al., 2006). In the closed conformation, loop D caps the channel from the cytoplasm and thereby occludes the pore. In the open conformation, loop D is displaced up to 16 Å, and this movement opens a hydrophobic gate blocking the channel entrance from the cytoplasm. These results reveal a molecular gating mechanism which appears conserved throughout all plant plasma membrane aquaporins. In plants it regulates water intake/export in response to water availability and cytoplasmic pH during anoxia (Törnroth-Horsefield et al., 2006).
The MIP superfamily includes three subfamilies: aquaporins, aquaglyceroporins and S-aquaporins. (1) The aquaporins (AQPs) are water selective. (2) The aquaglyceroporins are permeable to water, but also to other small uncharged molecules. (3) The third subfamily, with little conserved amino acid sequences around the NPA boxes, include 'superaquaporins' (S-aquaporins).The phylogeny of insect MIP family channels has been published (Finn et al. 2015). The arylsulfonamide AqB011 which selectively blocks the central ion pore
of mammalian AQP1 has been shown to impair migration of HT29 colon
cancer cells. Traditional herbal medicines are sources of selective AQP1
inhibitors that also slow cancer cell migration (Kourghi et al. 2018).
13 isoforms of mammalian aquaporins (AQP0 - AQP12),are known, 9 of which is localized in different parts of the renal tubular epithelium. Additional transport functions of renal AQPs (AQP3, AQP6, AQP7 and AQP8) are known. Aquaglyceroporins are most probably key elements in the renal regulation of nitrogen balance and maintenance of the correct pH of body fluids (Michalek 2016).
Otitis media (OM) refers to inflammatory diseases of the middle ear (ME), regardless of cause or pathological mechanism. The expression of aquaporins (AQPs) in the ME and Eustachian tube (ET) is relevant. Eleven types of AQPs, AQP1 to AQP11, have been found to be expressed in mammalian ME and ET (Jung et al. 2017). The distribution and levels of expression of AQPs depend on the presence or absence of inflammation. Fluid accumulation in the ME and ET is a common mechanism for all types of OM, causing edema in the tissue and inducing inflammation involving various AQPs. The expression patterns of several AQPs, especially AQP1, 4 and 5, may have immunological functions in OM.
Some classes of AQPs conduct ions, glycerol, urea, CO2 , nitric oxide, and other small solutes. Ion channel activity has been demonstrated for mammalian AQPs 0, 1, 6, Drosophila big brain (BIB), soybean nodulin 26, and rockcress AtPIP2;1 (Kourghi et al. 2017). Classification of AQPs into three categories
(orthodox AQPs, aquaglyceroporins and superaquaporins) is based on their
sequence similarities and substrate selectivities. In the male reproductive
tract of mammals, most AQPs (except AQP6 and AQP12)
are found in different organs (including testis, efferent ducts and
epididymis). AQP1 and AQP9 are the most abundant AQPs in the efferent
ducts and epididymis and play a crucial role for the
secretion/reabsorption dynamics of luminal fluid during sperm transport
and maturation. AQP3, AQP7, AQP8 and AQP11 are the most abundant AQPs in
sperm and are involved in the regulation of their volumes, which is
required for the differentiation of spermatids into spermatozoa during
spermatogenesis, as well as in sperm transit along environments of
different osmolality (male and female reproductive tracts). Mounting evidence indicates that AQP3, AQP7 and AQP11 are
involved in cryotolerance as well as the sperm response to variations of osmolality and to
freeze-thawing procedures (Yeste et al. 2017).
The generalized transport reaction for channel proteins of the MIP family is:
H2O (out) → H2O (in) (e.g., aquaporins)
solute (out) → solute (in) (e.g., glycerol facilitators).
This family belongs to the Major Intrinsic Protein (MIP) Superfamily.
Bienert, G.P., M.D. Schüssler, and T.P. Jahn. (2008). Metalloids: essential, beneficial or toxic? Major intrinsic proteins sort it out. Trends Biochem. Sci. 33: 20-26.
|Ahmadpour, D., E. Maciaszczyk-Dziubinska, R. Babazadeh, S. Dahal, M. Migocka, M. Andersson, R. Wysocki, M.J. Tamás, and S. Hohmann. (2016). The MAP kinase Slt2 modulates arsenite transport through the aquaglyceroporin Fps1. FEBS Lett. [Epub: Ahead of Print]|
|Amezcua-Romero JC., Pantoja O. and Vera-Estrella R. (2010). Ser123 is essential for the water channel activity of McPIP2;1 from Mesembryanthemum crystallinum. J Biol Chem. 285(22):16739-47.|
|Araya-Secchi, R., J.A. Garate, D.S. Holmes, and T. Perez-Acle. (2011). Molecular dynamics study of the archaeal aquaporin AqpM. BMC Genomics 12Suppl4: S8.|
|Assentoft, M., S. Kaptan, H.P. Schneider, J.W. Deitmer, B.L. de Groot, and N. MacAulay. (2016). Aquaporin 4 as a NH3 Channel. J. Biol. Chem. [Epub: Ahead of Print]|
|Au, C.G., T.L. Butler, J.R. Egan, S.T. Cooper, H.P. Lo, A.G. Compton, K.N. North, and D.S. Winlaw. (2008). Changes in skeletal muscle expression of AQP1 and AQP4 in dystrophinopathy and dysferlinopathy patients. Acta Neuropathol 116: 235-246.|
|Ayadi, M., D. Cavez, N. Miled, F. Chaumont, and K. Masmoudi. (2011). Identification and characterization of two plasma membrane aquaporins in durum wheat (Triticum turgidum L. subsp. durum) and their role in abiotic stress tolerance. Plant Physiol. Biochem 49: 1029-1039.|
|Beese-Sims, S.E., J. Lee, and D.E. Levin. (2011). Yeast Fps1 glycerol facilitator functions as a homotetramer. Yeast 28: 815-819.|
|Beitz, E., S. Pavlovic-Djuranovic, M. Yasui, P. Agre, and J.E. Schultz. (2004). Molecular dissection of water and glycerol permeability of the aquaglyceroporin from Plasmodium falciparum by mutational analysis. Proc. Natl. Acad. Sci. USA 101: 1153-1158. |
|Bellati, J., K. Alleva, G. Soto, V. Vitali, C. Jozefkowicz, and G. Amodeo. (2010). Intracellular pH sensing is altered by plasma membrane PIP aquaporin co-expression. Plant Mol. Biol. 74: 105-118.|
|Ben Amira, M., R. Mom, D. Lopez, H. Chaar, A. Khouaja, V. Pujade-Renaud, B. Fumanal, A. Gousset-Dupont, G. Bronner, P. Label, J.L. Julien, M.A. Triki, D. Auguin, and J.S. Venisse. (2018). MIP diversity from Trichoderma: Structural considerations and transcriptional modulation during mycoparasitic association with Fusarium solani olive trees. PLoS One 13: e0193760.|
|Berland, S., T.L. Toft-Bertelsen, I. Aukrust, J. Byska, M. Vaudel, L.A. Bindoff, N. MacAulay, and G. Houge. (2018). A de novo Ser111Thr variant in aquaporin-4 in a patient with intellectual disability, transient signs of brain ischemia, transient cardiac hypertrophy, and progressive gait disturbance. Cold Spring Harb Mol Case Stud 4:.|
|Berny, M.C., D. Gilis, M. Rooman, and F. Chaumont. (2016). Single mutations in the transmembrane domains of maize plasma membrane aquaporins affect the activity of the monomers within a heterotetramer. Mol Plant. [Epub: Ahead of Print]|
|Berthaud A., Manzi J., Perez J. and Mangenot S. (2012). Modeling detergent organization around aquaporin-0 using small-angle X-ray scattering. J Am Chem Soc. 134(24):10080-8.|
|Berthaud, A., F. Quemeneur, M. Deforet, P. Bassereau, F. Brochard-Wyart, and S. Mangenot. (2015). Spreading of porous vesicles subjected to osmotic shocks: the role of aquaporins. Soft Matter. [Epub: Ahead of Print]|
|Bertl, A., and R. Kaldenhoff. (2007). Function of a separate NH3-pore in Aquaporin TIP2;2 from wheat. FEBS Lett. 581: 5413-5417.|
|Bienert, G.P., A.L. Moller, K.A. Kristiansen, A. Schulz, I.M. Moller, J.K. Schjoerring, and T.P. Jahn. (2007). Specific aquaporins facilitate the diffusion of hydrogen peroxide across membranes. J. Biol. Chem. 282: 1183-1192. |
|Bienert, G.P., B. Desguin, F. Chaumont, and P. Hols. (2013). Channel-mediated lactic acid transport: a novel function for aquaglyceroporins in bacteria. Biochem. J. 454: 559-570.|
|Bienert, M.D., T.A. Diehn, N. Richet, F. Chaumont, and G.P. Bienert. (2018). Heterotetramerization of Plant PIP1 and PIP2 Aquaporins Is an Evolutionary Ancient Feature to Guide PIP1 Plasma Membrane Localization and Function. Front Plant Sci 9: 382.|
|Bonilla-Correal, S., F. Noto, E. Garcia-Bonavila, J.E. Rodríguez-Gil, M. Yeste, and J. Miro. (2017). First evidence for the presence of aquaporins in stallion sperm. Reprod Domest Anim 52Suppl4: 61-64.|
|Bui, L.C., C. Tomkiewicz, S. Pierre, A. Chevallier, R. Barouki, and X. Coumoul. (2016). Regulation of Aquaporin 3 Expression by the AhR Pathway Is Critical to Cell Migration. Toxicol Sci 149: 158-166.|
|Buzhynskyy, N., J.F. Girmens, W. Faigle, S. Scheuring. (2007). Human cataract lens membrane at subnanometer resolution. J. Mol. Biol. 374: 162-169. |
|Calamita, G., B. Kempf, M. Bonhivers, W.R. Bishai, E. Bremer, and P. Agre. (1998). Regulation of the Escherichia coli water channel gene aqpZ. Proc. Natl. Acad. Sci. USA 95: 3627-3631.|
|Calamita, G., J. Perret, and C. Delporte. (2018). Aquaglyceroporins: Drug Targets for Metabolic Diseases? Front Physiol 9: 851.|
|Calamita. G. (2000). The Escherichia coli aquaporin-Z water channel. Mol. Microbiol. 37: 254-262.|
|Carbrey, J.M., D.A. Gorelick-Feldman, D. Kozono, J. Praetorius, S. Nielsen, and P. Agre. (2003). Aquaglyceroporin AQP9: solute permeation and metabolic control of expression in liver. Proc. Natl. Acad. Sci. USA 100: 2945-2950. |
|Carbrey, J.M., M. Bonhivers, J.D. Boeke, and P. Agre. (2001). Aquaporins in Saccharomyces: characterization of a second functional water channel protein. Proc. Natl. Acad. Sci. USA 98: 1000-1005.|
|Chau, D., K. Ng, T.S. Chan, Y.Y. Cheng, B. Fong, S. Tam, Y.L. Kwong, and E. Tse. (2015). Azacytidine sensitizes acute myeloid leukemia cells to arsenic trioxide by up-regulating the arsenic transporter aquaglyceroporin 9. J Hematol Oncol 8: 46.|
|Chauvigne F., Zapater C., Stavang JA., Taranger GL., Cerda J. and Finn RN. (2015). The pH sensitivity of Aqp0 channels in tetraploid and diploid teleosts. FASEB J. 29(5):2172-84.|
|Chevalier, A.S. and F. Chaumont. (2015). The LxxxA motif in the third transmembrane helix of the maize aquaporin ZmPIP2;5 acts as an ER export signal. Plant Signal Behav 10: e990845.|
|Chiba, Y., N. Mitani, N. Yamaji, and J.F. Ma. (2009). HvLsi1 is a silicon influx transporter in barley. Plant J. 57: 810-818.|
|Choi, W.G., and D.M. Roberts. (2007). Arabidopsis NIP2;1, a major intrinsic protein transporter of lactic acid induced by anoxic stress. J. Biol. Chem. 282: 24209-24218.
|Chrispeels, M.J. and C. Maurel. (1994). Aquaporins: the molecular basis of facilitated water movement through living plant cells? Plant Physiol. 105: 9-13.|
|Cui, Y. and D.A. Bastien. (2011). Water transport in human aquaporin-4: Molecular dynamics (MD) simulations. Biochem. Biophys. Res. Commun. 412: 654-659.|
|Dai, Y.H., B.R. Liu, H.J. Chiang, and H.J. Lee. (2011). Gene transport and expression by arginine-rich cell-penetrating peptides in Paramecium. Gene 489: 89-97.|
|Danielsson, A., F. Pontén, L. Fagerberg, B.M. Hallström, J.M. Schwenk, M. Uhlén, O. Korsgren, and C. Lindskog. (2014). The human pancreas proteome defined by transcriptomics and antibody-based profiling. PLoS One 9: e115421.|
|de Paula Santos Martins, C., A.M. Pedrosa, D. Du, L.P. Gonçalves, Q. Yu, F.G. Gmitter, Jr, and M.G. Costa. (2015). Genome-Wide Characterization and Expression Analysis of Major Intrinsic Proteins during Abiotic and Biotic Stresses in Sweet Orange (Citrus sinensis L. Osb.). PLoS One 10: e0138786.|
|Dean, R.M., R.L. Rivers, M.L. Zeide, and D.M. Roberts. (1999). Purification and functional reconstitution of soybean nodulin 26. An aquaporin with water and glycerol transport properties. Biochemistry 38: 347-353.|
|Decker, K., M. Page, and A. Aksimentiev. (2017). Nanoscale Ion Pump Derived from a Biological Water Channel. J Phys Chem B 121: 7899-7906.|
|Deen, P.M.T. and C.H. van Os. (1998). Epithelial aquaporins. Curr. Opin. Cell Biol. 10: 435-442.|
|Di Giusto, G., P. Flamenco, V. Rivarola, J. Fernández, L. Melamud, P. Ford, and C. Capurro. (2012). Aquaporin 2-increased renal cell proliferation is associated with cell volume regulation. J. Cell. Biochem. 113: 3721-3729.|
|Dynowski, M., G. Schaaf, D. Loque, O. Moran, and U. Ludewig. (2008). Plant plasma membrane water channels conduct the signalling molecule H2O2. Biochem. J. 414: 53-61.|
|Engel, A., Y. Fujiyoshi, and P. Agre. (2000). The importance of aquaporin water channel protein structures. EMBO J. 19: 800-806.|
|Engel, A., Y. Fujiyoshi, T. Gonen, and T. Walz. (2008). Junction-forming aquaporins. Curr. Opin. Struct. Biol. 18: 229-235.|
|Fenton, R.A., H.B. Moeller, J.D. Hoffert, M.J. Yu, S. Nielsen, and M.A. Knepper. (2008). Acute regulation of aquaporin-2 phosphorylation at Ser-264 by vasopressin. Proc. Natl. Acad. Sci. U. S. A. 105: 3134-3139.|
|Figarella, K., M. Rawer, N.L. Uzcategui, B.K. Kubata, K. Lauber, F. Madeo, S. Wesselborg, and M. Duszenko. (2005). Prostaglandin D2 induces programmed cell death in Trypanosoma brucei bloodstream form. Cell Death Differ. 12: 335-346. |
|Figarella, K., N.L. Uzcategui, Y. Zhou, A. LeFurgey, M. Ouellette, H. Bhattacharjee, and R. Mukhopadhyay. (2007). Biochemical characterization of Leishmania major aquaglyceroporin LmAQP1: possible role in volume regulation and osmotaxis. Mol. Microbiol. 65: 1006-1017.|
|Figueiredo, B.C., N.R. De Assis, S.B. De Morais, V.P. Martins, N.D. Ricci, R.M. Bicalho, C.d.a.S. Pinheiro, and S.C. Oliveira. (2014). Immunological characterization of a chimeric form of Schistosoma mansoni aquaporin in the murine model. Parasitology 141: 1277-1288.|
|Finn, R.N., F. Chauvigné, J.A. Stavang, X. Belles, and J. Cerdà. (2015). Insect glycerol transporters evolved by functional co-option and gene replacement. Nat Commun 6: 7814.|
|Fontijn, R.D., O.L. Volger, T.C. van der Pouw-Kraan, A. Doddaballapur, T. Leyen, J.M. Baggen, R.A. Boon, and A.J. Horrevoets. (2015). Expression of Nitric Oxide-Transporting Aquaporin-1 Is Controlled by KLF2 and Marks Non-Activated Endothelium In Vivo. PLoS One 10: e0145777.|
|Frick, A., U.K. Eriksson, F. de Mattia, F. Oberg, K. Hedfalk, R. Neutze, W.J. de Grip, P.M. Deen, and S. Törnroth-Horsefield. (2014). X-ray structure of human aquaporin 2 and its implications for nephrogenic diabetes insipidus and trafficking. Proc. Natl. Acad. Sci. USA 111: 6305-6310.|
|Froger, A., J.-P. Rolland, P. Bron, V. Lagrée, F. Le Cahérec, S. Deschamps, J.-F. Hubert, I. Pellerin, D. Thomas, and C. Delamarche. (2001). Functional characterization of a microbial aquaglyceroporin. Microbiology 147: 1129-1135.|
|Fu, D., A. Libson, L.J.W. Miercke, C. Weitzman, P. Nollert, J. Krucinski, and R.M. Stroud. (2000). Structure of a glycerol-conducting channel and the basis for its selectivity. Science 290: 481-486.|
|Gao, J., X. Wang, Y. Chang, J. Zhang, Q. Song, H. Yu, and X. Li. (2006). Acetazolamide inhibits osmotic water permeability by interaction with aquaporin-1. Anal Biochem 350: 165-170.|
|Geadkaew, A., J. von Bülow, E. Beitz, S. Tesana, S. Vichasri Grams, and R. Grams. (2015). Bi-functionality of Opisthorchis viverrini aquaporins. Biochimie 108: 149-159.|
|Geijer C., Ahmadpour D., Palmgren M., Filipsson C., Klein DM., Tamas MJ., Hohmann S. and Lindkvist-Petersson K. (2012). Yeast aquaglyceroporins use the transmembrane core to restrict glycerol transport. J Biol Chem. 287(28):23562-70.|
|Geng, X., J. McDermott, J. Lundgren, L. Liu, K.J. Tsai, J. Shen, and Z. Liu. (2017). Role of AQP9 in transport of monomethyselenic acid and selenite. Biometals 30: 747-755.|
|Gerbeau, P., J. Güçlü, P. Ripoche, and C. Maurel. (1999). Aquaporin Nt-TIPa can account for the high permeability of tobacco cell vacuolar membrane to small neutral solutes. Plant J. 18: 577-587.|
|Gonen, T. and T. Walz. (2006). The structure of aquaporins. Q. Rev. Biophys. 39: 361-396. |
|Gonen, T., P. Sliz, J. Kistler, Y. Cheng, and T. Walz. (2004b). Aquaporin-0 membrane junctions reveal the structure of a closed water pore. Nature 429: 193-197.|
|Gonen, T., Y. Cheng, J. Kistler, and T. Walz. (2004a). Aquaporin-0 membrane junctions form upon proteolytic cleavage. J. Mol. Biol. 342: 1337-1345. |
|Gonen, T., Y. Cheng, P. Sliz, Y. Hiroaki, Y. Fujiyoshi, S.C. Harrison, and T. Walz. (2005). Lipid-protein interactions in double-layered two-dimensional AQP0 crystals. Nature 438: 633-638. Erratum in: Nature (2006) 441: 248.
|Gourbal, B., N. Sonuc, H. Bhattacharjee, D. Legare, S. Sundar, M. Ouellette, B.P. Rosen, and R. Mukhopadhyay. (2004). Drug uptake and modulation of drug resistance in Leishmania by an aquaglyceroporin. J. Biol. Chem. 279: 31010-31017. |
|Guo, H., M. Wei, Y. Liu, Y. Zhu, W. Xu, L. Meng, N. Wang, C. Shao, S. Lu, F. Gao, Z. Cui, Z. Wei, F. Zhao, and S. Chen. (2017). Molecular cloning and expression analysis of the aqp1aa gene in half-smooth tongue sole (Cynoglossus semilaevis). PLoS One 12: e0175033.|
|Hara-Chikuma, M., and A.S. Verkman. (2008). Prevention of skin tumorigenesis and impairment of epidermal cell proliferation by targeted aquaporin-3 gene disruption. Mol. Cell. Biol. 28: 326-332.|
|Heller, K.B., E.C. Lin, and T.H. Wilson. (1980). Substrate specificity and transport properties of the glycerol facilitator of Escherichia coli. J. Bacteriol. 144: 274-278.|
|Hemley SJ., Bilston LE., Cheng S., Chan JN. and Stoodley MA. (2013). Aquaporin-4 expression in post-traumatic syringomyelia. J Neurotrauma. 30(16):1457-67.|
|Herraiz, A., F. Chauvigné, J. Cerdà, X. Bellés, and M.D. Piulachs. (2011). Identification and functional characterization of an ovarian aquaporin from the cockroach Blattella germanica L. (Dictyoptera, Blattellidae). J Exp Biol 214: 3630-3638.|
|Hesler, R.A., J.J. Huang, M.D. Starr, V.M. Treboschi, A.G. Bernanke, A.B. Nixon, S.J. McCall, R.R. White, and G.C. Blobe. (2016). TGF-β-Induced Stromal CYR61 Promotes Resistance to Gemcitabine in Pancreatic Ductal Adenocarcinoma Through Down-Regulation of the Nucleoside Transporters hENT1 and hCNT3. Carcinogenesis. [Epub: Ahead of Print]|
|Heymann, J.B. and A. Engel. (2000). Structural clues in the sequences of the aquaporins. J. Mol. Biol. 295: 1039-1053.|
|Hill AE. and Shachar-Hill Y. (2015). Are Aquaporins the Missing Transmembrane Osmosensors? J Membr Biol. 248(4):753-65.|
|Hirota, A., Y. Takiya, J. Sakamoto, N. Shiojiri, M. Suzuki, S. Tanaka, and R. Okada. (2015). Molecular Cloning of cDNA Encoding an Aquaglyceroporin, AQP-h9, in the Japanese Tree Frog, Hyla japonica: Possible Roles of AQP-h9 in Freeze Tolerance. Zoolog Sci 32: 296-306.|
|Horsefield, R., K. Nordén, M. Fellert, A. Backmark, S. Törnroth-Horsefield, A.C. Terwisscha van Scheltinga, J. Kvassman, P. Kjellbom, U. Johanson, and R. Neutze. (2008). High-resolution x-ray structure of human aquaporin 5. Proc. Natl. Acad. Sci. USA 105: 13327-13332.|
|Hub, J.S. and B.L. de Groot. (2008). Mechanism of selectivity in aquaporins and aquaglyceroporins. Proc. Natl. Acad. Sci. USA 105: 1198-1203.|
|Hwang, J.H., S.R. Ellingson, and D.M. Roberts. (2010). Ammonia permeability of the soybean nodulin 26 channel. FEBS Lett. 584: 4339-4343.|
|Iena, F.M. and J. Lebeck. (2018). Implications of Aquaglyceroporin 7 in Energy Metabolism. Int J Mol Sci 19:.|
|Ikeda, M., E. Beitz, D. Kozono, W.B. Guggino, P. Agre, and M. Yasui. (2002). Characterization of aquaporin-6 as a nitrate channel in mammalian cells. Requirement of pore-lining residue threonine. J. Biol. Chem. 277: 39873-39879. |
|Ikezoe, K., T. Oga, T. Honda, M. Hara-Chikuma, X. Ma, T. Tsuruyama, K. Uno, J. Fuchikami, K. Tanizawa, T. Handa, Y. Taguchi, A.S. Verkman, S. Narumiya, M. Mishima, and K. Chin. (2016). Aquaporin-3 potentiates allergic airway inflammation in ovalbumin-induced murine asthma. Sci Rep 6: 25781.|
|Isayenkov, S.V. and F.J. Maathuis. (2008). The Arabidopsis thaliana aquaglyceroporin AtNIP7;1 is a pathway for arsenite uptake. FEBS Lett. 582: 1625-1628.|
|Ishibashi, K. (2006). Aquaporin subfamily with unusual NPA boxes. Biochim. Biophys. Acta. 1758: 989-993.|
|Ishibashi, K., Y. Morishita, and Y. Tanaka. (2017). The Evolutionary Aspects of Aquaporin Family. Adv Exp Med Biol 969: 35-50.|
|Ishida Y., Nagae T. and Azuma M. (2012). A water-specific aquaporin is expressed in the olfactory organs of the blowfly, Phormia regina. J Chem Ecol. 38(8):1057-61.|
|Ishikawa, F., S. Suga, T. Uemura, M.H. Sato, and M. Maeshima. (2005). Novel type aquaporin SIPs are mainly localized to the ER membrane and show cell-specific expression in Arabidopsis thaliana. FEBS Lett. 579: 5814-5820. |
|Jelen S., Gena P., Lebeck J., Rojek A., Praetorius J., Frokiaer J., Fenton RA., Nielsen S., Calamita G. and Rutzler M. (2012). Aquaporin-9 and urea transporter-A gene deletions affect urea transmembrane passage in murine hepatocytes. Am J Physiol Gastrointest Liver Physiol. 303(11):G1279-87.|
|Jiang, J., B.V. Daniels, and D. Fu. (2006). Crystal structure of AqpZ tetramer reveals two distinct Arg-189 conformations associated with water permeation through the narrowest constriction of the water-conducting channel. J. Biol. Chem. 281: 454-460. |
|Jung, H.J., J.Y. Park, H.S. Jeon, and T.H. Kwon. (2011). Aquaporin-5: a marker protein for proliferation and migration of human breast cancer cells. PLoS One 6: e28492.|
|Jung, S.Y., S.S. Kim, Y.I. Kim, S.H. Kim, and S.G. Yeo. (2017). A Review: Expression of Aquaporins in Otitis Media. Int J Mol Sci 18:.|
|Jungersted JM., Bomholt J., Bajraktari N., Hansen JS., Klaerke DA., Pedersen PA., Hedfalk K., Nielsen KH., Agner T. and Helix-Nielsen C. (2013). In vivo studies of aquaporins 3 and 10 in human stratum corneum. Arch Dermatol Res. 305(8):699-704.|
|Kalluri, S.R., V. Rothhammer, O. Staszewski, R. Srivastava, F. Petermann, M. Prinz, B. Hemmer, and T. Korn. (2011). Functional characterization of aquaporin-4 specific T cells: towards a model for neuromyelitis optica. PLoS One 6: e16083.|
|Kaptan S., Assentoft M., Schneider HP., Fenton RA., Deitmer JW., MacAulay N. and de Groot BL. (2015). H95 Is a pH-Dependent Gate in Aquaporin 4. Structure. 23(12):2309-18.|
|Kikawada, T., A. Saito, Y. Kanamori, M. Fujita, K. Snigórska, M. Watanabe, and T. Okuda. (2008). Dehydration-inducible changes in expression of two aquaporins in the sleeping chironomid, Polypedilum vanderplanki. Biochim. Biophys. Acta. 1778: 514-520.|
|Klein, N., J. Neumann, J.D. O''Neil, and D. Schneider. (2015). Folding and stability of the aquaglyceroporin GlpF: Implications for human aqua(glycero)porin diseases. Biochim. Biophys. Acta. 1848: 622-633.|
|Kosinska Eriksson, U., G. Fischer, R. Friemann, G. Enkavi, E. Tajkhorshid, and R. Neutze. (2013). Subangstrom resolution X-ray structure details aquaporin-water interactions. Science 340: 1346-1349.|
|Koun, S., J.D. Kim, M. Rhee, M.J. Kim, and T.L. Huh. (2016). Spatiotemporal expression pattern of the zebrafish aquaporin 8 family during early developmental stages. Gene Expr Patterns 21: 1-6.|
|Kourghi, M., J.V. Pei, M.L. De Ieso, S. Nourmohammadi, P.H. Chow, and A.J. Yool. (2018). Fundamental structural and functional properties of Aquaporin ion channels found across the kingdoms of life. Clin Exp Pharmacol Physiol 45: 401-409.|
|Kourghi, M., M.L. De Ieso, S. Nourmohammadi, J.V. Pei, and A.J. Yool. (2018). Identification of Loop D Domain Amino Acids in the Human Aquaporin-1 Channel Involved in Activation of the Ionic Conductance and Inhibition by AqB011. Front Chem 6: 142.|
|Kozono, D., X. Ding, I. Iwasaki, X. Meng, Y. Kamagata, P. Agre, and Y. Kitagawa. (2003). Functional expression and characterization of an archaeal aquaporin. AqpM from Methanothermobacter marburgensis. J. Biol. Chem. 278: 10649-10656. |
|Kubota, M., T. Hasegawa, T. Nakakura, H. Tanii, M. Suzuki, and S. Tanaka. (2006). Molecular and cellular characterization of a new aquaporin, AQP-x5, specifically expressed in the small granular glands of Xenopus skin. J Exp Biol 209: 3199-3208.|
|Lebeck, J. (2014). Metabolic impact of the glycerol channels AQP7 and AQP9 in adipose tissue and liver. J Mol Endocrinol 52: R165-178.|
|Lebeck, J., M.U. Cheema, M.T. Skowronski, S. Nielsen, and J. Praetorius. (2015). Hepatic AQP9 expression in male rats is reduced in response to PPARα agonist treatment. Am. J. Physiol. Gastrointest Liver Physiol 308: G198-205.|
|Lee, J.K., D. Kozono, J. Remis, Y. Kitagawa, P. Agre, and R.M. Stroud. (2005). Structural basis for conductance by the archaeal aquaporin AqpM at 1.68 Å. Proc. Natl. Acad. Sci. USA 102: 18932-18937.|
|Leung, J., A. Pang, W.H. Yuen, Y.L. Kwong, and E.W. Tse. (2007). Relationship of expression of aquaglyceroporin 9 with arsenic uptake and sensitivity in leukemia cells. Blood 109: 740-746.|
|Li, H., S. Lee, and B.K. Jap. (1997). Molecular design of aquaporin-1 water channel as revealed by electrocrystallography. Nature Struc. Biol. 4: 263-265.|
|Li, J. and A.S. Verkman. (2001). Impaired hearing in mice lacking aquaporin-4 water channels. J. Biol. Chem. 276: 31233-31237.|
|Li, R.Y., Y. Ago, W.J. Liu, N. Mitani, J. Feldmann, S.P. McGrath, J.F. Ma, and F.J. Zhao. (2009). The rice aquaporin Lsi1 mediates uptake of methylated arsenic species. Plant Physiol. 150: 2071-2080.|
|Li, T., W.G. Choi, I.S. Wallace, J. Baudry, and D.M. Roberts. (2011). Arabidopsis thaliana NIP7;1: an anther-specific boric acid transporter of the aquaporin superfamily regulated by an unusual tyrosine in helix 2 of the transport pore. Biochemistry 50: 6633-6641.|
|Li, Z., B. Li, L. Zhang, L. Chen, G. Sun, Q. Zhang, J. Wang, X. Zhi, L. Wang, Z. Xu, and H. Xu. (2016). The proliferation impairment induced by AQP3 deficiency is the result of glycerol uptake and metabolism inhibition in gastric cancer cells. Tumour Biol 37: 9169-9179.|
|Lind, U., M. Järvå, M. Alm Rosenblad, P. Pingitore, E. Karlsson, A.L. Wrange, E. Kamdal, K. Sundell, C. André, P.R. Jonsson, J. Havenhand, L.A. Eriksson, K. Hedfalk, and A. Blomberg. (2017). Analysis of aquaporins from the euryhaline barnacle Balanus improvisus reveals differential expression in response to changes in salinity. PLoS One 12: e0181192.|
|Liu, K., H. Tsujimoto, S.J. Cha, P. Agre, and J.L. Rasgon. (2011). Aquaporin water channel AgAQP1 in the malaria vector mosquito Anopheles gambiae during blood feeding and humidity adaptation. Proc. Natl. Acad. Sci. USA 108: 6062-6066.|
|Loqué, D., U. Ludewig, L. Yuan, and N. von Wirén. (2005). Tonoplast intrinsic proteins AtTIP2;1 and AtTIP2;3 facilitate NH3 transport into the vacuole. Plant Physiology 137: 671-680. |
|Lu, D.C., H. Zhang, Z. Zador, and A.S. Verkman. (2008). Impaired olfaction in mice lacking aquaporin-4 water channels. FASEB J. 22: 3216-3223.|
|Lu, M.X., D.D. Pan, J. Xu, Y. Liu, G.R. Wang, and Y.Z. Du. (2018). Identification and Functional Analysis of the First Aquaporin from Striped Stem Borer,. Front Physiol 9: 57.|
|Ma, J.F., K. Tamai, N. Yamaji, N. Mitani, S. Konishi, M. Katsuhara, M. Ishiguro, Y. Murata, and M. Yano. (2007b). A silicon transporter in rice. Nature 440: 688-691. |
|Ma, J.F., N. Yamaji, K. Tamai, and N. Mitani. (2007a). Genotypic difference in silicon uptake and expression of silicon transporter genes in rice. Plant Physiol. 145: 919-924. |
|Mahdieh, M., A. Mostajeran, T. Horie, and M. Katsuhara. (2008). Drought stress alters water relations and expression of PIP-type aquaporin genes in Nicotiana tabacum plants. Plant Cell Physiol. 49: 801-813.|
|Mallo, R.C. and Ashby, M.T. (2006). AqpZ-mediated water permeability in Escherichia coli measured by stopped-flow spectroscopy. J. Bacteriol. 188:820-822. |
|Martos-Sitcha, J.A., M.A. Campinho, J.M. Mancera, G. Martínez-Rodríguez, and J. Fuentes. (2015). Vasotocin and isotocin regulate aquaporin 1 function in the sea bream. J Exp Biol 218: 684-693.|
|Mathew, L.G., E.M. Campbell, A.J. Yool, and J.A. Fabrick. (2011). Identification and characterization of functional aquaporin water channel protein from alimentary tract of whitefly, Bemisia tabaci. Insect Biochem Mol Biol 41: 178-190.|
|Matsui, H., B. Hopkinson, K. Nakajima, and Y. Matsuda. (2018). Plasma-membrane-type aquaporins from marine diatoms function as CO2/NH3 channels and provide photoprotection. Plant Physiol. [Epub: Ahead of Print]|
|McDermott JR., Jiang X., Beene LC., Rosen BP. and Liu Z. (2010). Pentavalent methylated arsenicals are substrates of human AQP9. Biometals. 23(1):119-27.|
|Méndez-Giménez, L., S. Ezquerro, I.V. da Silva, G. Soveral, G. Frühbeck, and A. Rodríguez. (2018). Pancreatic Aquaporin-7: A Novel Target for Anti-diabetic Drugs? Front Chem 6: 99.|
|Meng, Y.-L., Z. Liu, and B.P. Rosen. (2004). As(III) and Sb(III) uptake by GlpF and efflux by ArsB in Escherichia coli. J. Biol. Chem. 279: 18334-18341.|
|Michalek, K. (2016). Aquaglyceroporins in the kidney: present state of knowledge and prospects. J. Physiol. Pharmacol 67: 185-193.|
|Mitani N., N. Yamaji, J.F. Ma. (2008). Characterization of substrate specificity of a rice silicon transporter, Lsi1. Pflugers Arch : .|
|Moe, S.E., J.G. Sorbo, R. Sogaard, T. Zeuthen, O. Petter Ottersen, and T. Holen. (2008). New isoforms of rat Aquaporin-4. Genomics 91: 367-377.|
|Mukhopadhyay R., Bhattacharjee H. and Rosen BP. (2014). Aquaglyceroporins: generalized metalloid channels. Biochim Biophys Acta. 1840(5):1583-91.|
|Murata, K., K. Mitsuoka, T. Hirai, T. Walz, P. Agre, J.B. Heymann, A. Engel, and Y. Fujiyoshi. (2000). Structural determinants of water permeation through aquaporin-1. Science 407: 599-605.|
|Najafabadi, H.S., N. Torabi, and M. Chamankhah. (2008). Designing multiple degenerate primers via consecutive pairwise alignments. BMC Bioinformatics 9: 55.|
|Nakazawa, Y., M. Oka, A. Mitsuishi, M. Bando, and M. Takehana. (2011). Quantitative analysis of ascorbic acid permeability of aquaporin 0 in the lens. Biochem. Biophys. Res. Commun. 415: 125-130.|
|Navarro-Ródenas, A., J.M. Ruíz-Lozano, R. Kaldenhoff, and A. Morte. (2012). The aquaporin TcAQP1 of the desert truffle Terfezia claveryi is a membrane pore for water and CO(2) transport. Mol. Plant Microbe Interact. 25: 259-266.|
|Nemeth-Cahalan, K.L., K. Kalman, A. Froger, and J. E. Hall. (2007). Zinc Modulation of Water Permeability Reveals that Aquaporin 0 Functions as a Cooperative Tetramer. J. Gen. Physiol. 130(5):457-464.|
|Niemietz, C.M. and S.D. Tyerman. (2000). Channel-mediated permeation of ammonia gas through the peribacteroid membrane of soybean nodules. FEBS Lett. 465: 110-114.|
|Nishihara, E., E. Yokota, A. Tazaki, H. Orii, M. Katsuhara, K. Kataoka, H. Igarashi, Y. Moriyama, T. Shimmen, and S. Sonobe. (2008). Presence of aquaporin and V-ATPase on the contractile vacuole of Amoeba proteus. Biol Cell 100: 179-188.|
|Nozaki, K., D. Ishii, and K. Ishibashi. (2008). Intracellular aquaporins: clues for intracellular water transport? Pflugers Arch 456(4): 701-707.|
|Olesen, E.T. and R.A. Fenton. (2017). Aquaporin-2 membrane targeting: still a conundrum. Am. J. Physiol. Renal Physiol ajprenal.00010.2017. [Epub: Ahead of Print]|
|Oliveira, R., F. Lages, M. Silva-Graça, and C. Lucas. (2003). Fps1p channel is the mediator of the major part of glycerol passive diffusion in Saccharomyces cerevisiae: artefacts and re-definitions. Biochim. Biophys. Acta. 1613: 57-71. |
|Palmgren, M., M. Hernebring, S. Eriksson, K. Elbing, C. Geijer, S. Lasič, P. Dahl, J.S. Hansen, D. Topgaard, and K. Lindkvist-Petersson. (2017). Quantification of the Intracellular Life Time of Water Molecules to Measure Transport Rates of Human Aquaglyceroporins. J. Membr. Biol. [Epub: Ahead of Print]|
|Pareek G., Krishnamoorthy V. and D'Silva P. (2013). Molecular insights revealing interaction of Tim23 and channel subunits of presequence translocase. Mol Cell Biol. 33(23):4641-59.|
|Park, J.H. and M.H. Saier, Jr. (1996). Phylogenetic characterization of the MIP family of transmembrane channel proteins. J. Membr. Biol. 153: 171-180.|
|Philip, B.N., A.J. Kiss, and R.E. Lee, Jr. (2011). The protective role of aquaporins in the freeze-tolerant insect Eurosta solidaginis: functional characterization and tissue abundance of EsAQP1. J Exp Biol 214: 848-857.|
|Pietrement, C., N. Da Silva, C. Silberstein, M. James, M. Marsolais, A. Van Hoek, D. Brown, N. Pastor-Soler, N. Ameen, R. Laprade, V. Ramesh, and S. Breton. (2008). Role of NHERF1, Cystic Fibrosis transmembrane conductance regulator, and cAMP in the regulation of aquaporin 9. J. Biol. Chem. 283: 2986-2996.|
|Pillitteri, L.J., N.L. Bogenschutz, and K.U. Torii. (2008). The bHLH protein, MUTE, controls differentiation of stomata and the hydathode pore in arabidopsis. Plant Cell Physiol. 49: 934-943.|
|Pust, A., D. Kylies, C. Hube-Magg, M. Kluth, S. Minner, C. Koop, T. Grob, M. Graefen, G. Salomon, M.C. Tsourlakis, J. Izbicki, C. Wittmer, H. Huland, R. Simon, W. Wilczak, G. Sauter, S. Steurer, T. Krech, T. Schlomm, and N. Melling. (2015). Aquaporin 5 expression is frequent in prostate cancer and shows a dichotomous correlation with tumor phenotype and PSA recurrence. Hum Pathol. [Epub: Ahead of Print]|
|Ramírez-Lorca, R., A.M. Muñoz-Cabello, J.J. Toledo-Aral, A.A. Ilundáin, and M. Echevarría. (2006). Aquaporins in chicken: localization of ck-AQP5 along the small and large intestine. Comp Biochem Physiol A Mol Integr Physiol 143: 269-277.|
|Reizer, J., A. Reizer, and M.H. Saier, Jr. (1993). The MIP family of integral membrane channel proteins: sequence comparisons, evolutionary relationships, reconstructed pathway of evolution and proposed functional differentiation of the two repeated halves of the proteins. Crit. Rev. Biochem. Mol. Biol. 28: 235-257.|
|Saparov, S.M., D. Kozono, U. Rothe, P. Agre, and P. Pohl. (2001). Water and ion permeation of aquaporin-1 in planar lipid bilayers. Major differences in structural determinants and stoichiometry. J. Biol. Chem. 276: 31515-31520.|
|Saparov, S.M., K. Liu, P. Agre, and P. Pohl. (2007). Fast and selective ammonia transport by aquaporin-8. J. Biol. Chem. 282: 5296-5301.
|Savage, D.F., P.F. Egea, Y. Robles-Colmenares, J.D. O''Connell, 3rd, and R.M. Stroud. (2003). Architecture and selectivity in aquaporins: 2.5 a X-ray structure of aquaporin Z. PLoS Biol 1: E72.|
|Schmidt, R.S., J.P. Macêdo, M.E. Steinmann, A.G. Salgado, P. Bütikofer, E. Sigel, D. Rentsch, and P. Mäser. (2018). Transporters of Trypanosoma brucei-phylogeny, physiology, pharmacology. FEBS J. 285: 1012-1023.|
|Shibata, Y., I. Katayama, T. Nakakura, Y. Ogushi, R. Okada, S. Tanaka, and M. Suzuki. (2015). Molecular and cellular characterization of urinary bladder-type aquaporin in Xenopus laevis. Gen Comp Endocrinol 222: 11-19.|
|Shukla, V.K. and M.J. Chrispeels. (1998). Aquaporins: their role and regulation in cellular water movement. NATO-ASI Series (subseries H). Cellular integration of signaling pathways in plant development, pp.11-22. Springer-Verlag.|
|Sidoux-Walter, F., N. Pettersson, and S. Hohmann. (2004). The Saccharomyces cerevisiae aquaporin Aqy1 is involved in sporulation. Proc. Natl. Acad. Sci. USA 101: 17422-17427. |
|Soria LR., Fanelli E., Altamura N., Svelto M., Marinelli RA. and Calamita G. (2010). Aquaporin-8-facilitated mitochondrial ammonia transport. Biochem Biophys Res Commun. 393(2):217-21.|
|Soto, G., K. Alleva, M.A. Mazzella, G. Amodeo, and J.P. Muschietti. (2008). AtTIP1;3 and AtTIP5;1, the only highly expressed Arabidopsis pollen-specific aquaporins, transport water and urea. FEBS Lett. 582: 4077-4082.|
|Soto, G., R. Fox, N. Ayub, K. Alleva, F. Guaimas, E.J. Erijman, A. Mazzella, G. Amodeo, and J. Muschietti. (2010). TIP5;1 is an aquaporin specifically targeted to pollen mitochondria and is probably involved in nitrogen remobilization in Arabidopsis thaliana. Plant J. 64: 1038-1047.|
|Stavang, J.A., F. Chauvigné, H. Kongshaug, J. Cerdà, F. Nilsen, and R.N. Finn. (2015). Phylogenomic and functional analyses of salmon lice aquaporins uncover the molecular diversity of the superfamily in Arthropoda. BMC Genomics 16: 618.|
|Stogsdill, B., J. Frisbie, C.M. Krane, and D.L. Goldstein. (2017). Expression of the aquaglyceroporin HC-9 in a freeze-tolerant amphibian that accumulates glycerol seasonally. Physiol Rep 5:.|
|Stokum, J.A., M.S. Kwon, S.K. Woo, O. Tsymbalyuk, R. Vennekens, V. Gerzanich, and J.M. Simard. (2017). SUR1-TRPM4 and AQP4 form a heteromultimeric complex that amplifies ion/water osmotic coupling and drives astrocyte swelling. Glia. [Epub: Ahead of Print]|
|Suzuki, H., K. Nishikawa, Y. Hiroaki, and Y. Fujiyoshi. (2008). Formation of aquaporin-4 arrays is inhibited by palmitoylation of N-terminal cysteine residues. Biochim. Biophys. Acta. 1778(4): 1181-1189.|
|Törnroth-Horsefield, S., Y. Wang, K. Hedfalk, U. Johanson, M. Karlsson, E. Tajkhorshid, R. Neutze, and P. Kjellbom. (2006). Structural mechanism of plant aquaporin gating. Nature 439: 688-694.|
|Takahashi, G., S. Hasegawa, Y. Fukutomi, C. Harada, M. Furugori, Y. Seki, Y. Kikkawa, and K. Wada. (2017). A novel missense mutation of Mip causes semi-dominant cataracts in the Nat mouse. Exp Anim 66: 271-282.|
|Takano, J., M. Wada, U. Ludewig, G. Schaaf, N. von Wirén, and T. Fujiwara. (2006). The Arabidopsis major intrinsic protein NIP5;1 is essential for efficient boron uptake and plant development under boron limitation. The Plant Cell 18: 1498-1509.|
|Tang, H., C. Shao, and J. He. (2017). Down-regulated expression of aquaporin-4 in the cerebellum after status epilepticus. Cogn Neurodyn 11: 183-188.|
|Tani, K., T. Mitsuma, Y. Hiroaki, A. Kamegawa, K. Nishikawa, Y. Tanimura, and Y. Fujiyoshi. (2009). Mechanism of aquaporin-4's fast and highly selective water conduction and proton exclusion. J. Mol. Biol. 389: 694-706.|
|Uehlein, N., B. Otto, D.T. Hanson, M. Fischer, N. McDowell, and R. Kaldenhoff. (2008). Function of Nicotiana tabacum Aquaporins as Chloroplast Gas Pores Challenges the Concept of Membrane CO2 Permeability. Plant Cell 20: 648-657.|
|Uehlein, N., C. Lovisolo, F. Siefritz, and R. Kaldenhoff. (2003). The tobacco aquaporin NtAQP1 is a membrane CO2 pore with physiological functions. Nature (in press).|
|Uzcategui, N.L., A. Szallies, S. Pavlovic-Djuranovic, M. Palmada, K. Figarella, C. Boehmer, F. Lang, E. Beitz, and M. Duszenko. (2004). Cloning, heterologous expression, and characterization of three aquaglyceroporins from Trypanosoma brucei. J. Biol. Chem. 279: 42669-42676. |
|Vajpai, M., M. Mukherjee, and R. Sankararamakrishnan. (2018). Cooperativity in Plant Plasma Membrane Intrinsic Proteins (PIPs): Mechanism of Increased Water Transport in Maize PIP1 Channels in Hetero-tetramers. Sci Rep 8: 12055.|
|Varadaraj, K., S.S. Kumari, R. Patil, M.B. Wax, and R.T. Mathias. (2008). Functional characterization of a human aquaporin 0 mutation that leads to a congenital dominant lens cataract. Exp Eye Res 87: 9-21.|
|Verdoucq, L., A. Grondin, and C. Maurel. (2008). Structure-function analysis of plant aquaporin AtPIP2;1 gating by divalent cations and protons. Biochem. J. 415: 409-416.|
|Verma, R.K., A.B. Gupta, and R. Sankararamakrishnan. (2015). Major intrinsic protein superfamily: channels with unique structural features and diverse selectivity filters. Methods Enzymol 557: 485-520.|
|Viadiu, H., T. Gonen, and T. Walz. (2007). Projection map of aquaporin-9 at 7 Å resolution. J. Mol. Biol. 367: 80-88.|
|Virkki MT., Agrawal N., Edsbacker E., Cristobal S., Elofsson A. and Kauko A. (2014). Folding of Aquaporin 1: multiple evidence that helix 3 can shift out of the membrane core. Protein Sci. 23(7):981-92.|
|von Bülow, J., A. Golldack, T. Albers, and E. Beitz. (2015). The amoeboidal Dictyostelium aquaporin AqpB is gated via Tyr216 and aqpB gene deletion affects random cell motility. Biol Cell 107: 78-88.|
|Wang, F. and B. Ye. (2016). Bioinformatics analysis and construction of phylogenetic tree of aquaporins from Echinococcus granulosus. Parasitol Res 115: 3499-3511.|
|Wang, L., Q. Li, Q. Lei, C. Feng, Y. Gao, X. Zheng, Y. Zhao, Z. Wang, and J. Kong. (2015). MzPIP2;1: An Aquaporin Involved in Radial Water Movement in Both Water Uptake and Transportation, Altered the Drought and Salt Tolerance of Transgenic Arabidopsis. PLoS One 10: e0142446.|
|Watanabe, S., C.S. Moniaga, S. Nielsen, and M. Hara-Chikuma. (2016). Aquaporin-9 facilitates membrane transport of hydrogen peroxide in mammalian cells. Biochem. Biophys. Res. Commun. 471: 191-197.|
|Wysocki, R., C.C. Chéry, D. Wawrzycka, M. Van Hulle, R. Cornelis, J.M. Thevelein, and M.J. Tamás. (2001). The glycerol channel Fps1p mediates the uptake of arsenite and antimonite in Saccharomyces cerevisiae. Mol. Microbiol. 40: 1391-1401.|
|Yaba, A., B. Sozen, B. Suzen, and N. Demir. (2017). Expression of aquaporin-7 and aquaporin-9 in tanycyte cells and choroid plexus during mouse estrus cycle. Morphologie 101: 39-46.|
|Yang, B., Z. Zador, and A.S. Verkman. (2008). Glial cell aquaporin-4 overexpression in transgenic mice accelerates cytotoxic brain swelling. J. Biol. Chem. 283: 15280-15286.|
|Yang, G., G. Zhang, Q. Wu, and J. Zhao. (2011). A novel mutation in the MIP gene is associated with autosomal dominant congenital nuclear cataract in a Chinese family. Mol Vis 17: 1320-1323.|
|Yang, H.-C., J. Cheng, T.M. Finan, B.P. Rosen, and H. Bhattacharjee. (2005). Novel pathway for arsenic detoxification in the legume symbiont Sinorhizobium meliloti. J. Bacteriol. 187: 6991-6997.|
|Yasui, M., A. Hazama, T.-H. Kwon, S. Nielsen, W.B. Guggino, and P. Agre. (1999). Rapid gating and anion permeability of an intracellular aquaporin. Nature 402: 184-187.|
|Yeste, M., R. Morató, J.E. Rodríguez-Gil, S. Bonet, and N. Prieto-Martínez. (2017). Aquaporins in the male reproductive tract and sperm: Functional implications and cryobiology. Reprod Domest Anim 52Suppl4: 12-27.|
|Yoo, Y.J., H.K. Lee, W. Han, D.H. Kim, M. Lee, J. Jeon, D.W. Lee, J. Lee, Y. Lee, J. Lee, J.S. Kim, Y. Cho, J.K. Han, and I. Hwang. (2016). Interactions between transmembrane helices within monomers of the aquaporin AtPIP2;1 play a crucial role in tetramer formation. Mol Plant. [Epub: Ahead of Print]|
|Yool, A.J. (2007). Dominant-negative suppression of big brain ion channel activity by mutation of a conserved glutamate in the first transmembrane domain. Gene Expr. 13: 329-337.|
|Yool, A.J. and E.M. Campbell. (2012). Structure, function and translational relevance of aquaporin dual water and ion channels. Mol Aspects Med 33: 553-561.|
|Yu, X.S., X. Yin, E.M. Lafer, and J.X. Jiang. (2005). Developmental regulation of the direct interaction between the intracellular loop of connexin 45.6 and the C terminus of major intrinsic protein (aquaporin-0). J. Biol. Chem. 280: 22081-22090.
|Zardoya, R. and S. Villalba. (2001). A phylogenetic framework for the aquaporin family in eukaryotes. J. Mol. Evol. 52: 391-404.|
|Zeuthen T., B. Wu, S. Pavlovic-Djuranovic, L.M. Holm, N.L. Uzcategui, M. Duszenko, J.F. Kun, J.E. Schultz, E. Beitz. (2006). Ammonia permeability of the aquaglyceroporins from Plasmodium falciparum, Toxoplasma gondii and Trypansoma brucei. Mol. Microbiol. 61: 1598-1608.|
|Zhang, H. and A.S. Verkman. (2010). Aquaporin-1 tunes pain perception by interaction with Na(v)1.8 Na+ channels in dorsal root ganglion neurons. J. Biol. Chem. 285: 5896-5906.|
|Zhang, Z., P. Xu, Z. Xie, F. Shen, N. Chen, L. Yu, and R. He. (2017). Downregulation of AQP2 in the anterior vaginal wall is associated with the pathogenesis of female stress urinary incontinence. Mol Med Rep 16: 3503-3509.|
|Zhao, R., X. Liang, M. Zhao, S.L. Liu, Y. Huang, S. Idell, X. Li, and H.L. Ji. (2014). Correlation of apical fluid-regulating channel proteins with lung function in human COPD lungs. PLoS One 9: e109725.|
|Zhao, X.Q., N. Mitani, N. Yamaji, R.F. Shen, and J.F. Ma. (2010). Involvement of silicon influx transporter OsNIP2;1 in selenite uptake in rice. Plant Physiol. 153: 1871-1877.|
|Zhou, Y., L. Li, J. Qian, H. Jia, and Y. Cui. (2018). Identification of three aquaporin subgroups from Blomia tropicalis by transcriptomics. Int J Mol Med. [Epub: Ahead of Print]|
|Zwiazek, J.J., H. Xu, X. Tan, A. Navarro-Ródenas, and A. Morte. (2017). Significance of oxygen transport through aquaporins. Sci Rep 7: 40411.|
Glycerol facilitator, GlpF. Transports various polyols with decreasing rates as size increases (Heller et al. 1980); also transports arsenite (As(III) and antimonite (Sb(III)) (Meng et al., 2004).
GlpF of E. coli
Aqp1 of 270 aas and 6 TMSs. Induced by NH3 but not CO2, but transports both gases. Aqp1 is found in the plasma membrae as well as the ER/chloroplast. Aqp1 may be involved in photoprotection. It may facilitate the efflux of NH3, preventing the uncoupling effect of high intracellular ammonia concentrations (Matsui et al. 2018).
Aqp1 of Phaeodactylum tricornutum, a marine photoautotrophic diatoms
|1.A.8.10.1||Tonoplast intrinsic protein ||Plants ||TIP of Arabidopsis thaliana (P26587)|
|1.A.8.10.10||Aquaporin TIP2-1 (Delta-tonoplast intrinsic protein) (Delta-TIP) (Tonoplast intrinsic protein 2-1) (AtTIP2;1)||Plants||TIP2-1 of Arabidopsis thaliana |
|1.A.8.10.11||Probable aquaporin TIP-type alpha (Alpha TIP) (Tonoplast intrinsic protein alpha)||Plants||TIPA_PHAVU of Phaseolus vulgaris |
|1.A.8.10.12||Aquaporin SIP2-1 (OsSIP2;1) (Small basic intrinsic protein 2-1)|
|SIP2-1 of Oryza sativa subsp. japonica |
|AQP of Enterocytozoon bieneusi |
Uncharacterized protein of 295 aas and 6 TMSs.
UP of Volvox carteri
Aquaporin-8 (Aqp8) transporter, permeable to water, NH3, formamide and H2O2 (present in the inner membrane of mitochondria and the plasma membrane) (Bienert et al., 2007; Saparov et al., 2007; Soria et al., 2010).
Aqp8 of Homo sapiens (O94778)
Aqp8a.1 of 260 aas and 6 TMSs. The spaciotemporal pattern of induction of three aquaporins during embyonic development in Zebrafish has been determined, and all three, Aqp8a.1, Aqp8a.2 and Aqp8b, show distictive patterns (Koun et al. 2016).
Aqp8a.1 of Danio rerio (Zebrafish) (Brachydanio rerio)
|1.A.8.10.2||Tonoplast intrinsic protein-a (transports water, urea, glycerol and gases (CO2 and NH3) ||Plants ||TIPa of Nicotiana tabacum (Q9XG70)|
|1.A.8.10.3||Tonoplast intrinsic protein 1.1 (permeable to water and H2O2)||Plants||Tip1.1 of Arabidopsis thaliana (P25818)|
|1.A.8.10.4||Vacuolar (tonoplast) NH3 channel, TIP2;3 (Loque et al., 2005). [Tip2;2 of wheat is also an NH3/H2O channel (Bertl and Kaldenhoff, 2007)]. ||Plants||TIP2;3 of Arabidopsis thaliana (Q9FGL2)|
Endoplasmic reticulum Small and Basic Intrinsic Protein; (SIP1;1) water channel (present in all plant tissues except seeds) (Ishikawa et al., 2005) May play a role in gas and water exchange between the plant and its environment via stromata (turgor-driven epidermal valves) and the hydathode pore (Pillitteri et al., 2008).
SIP1;1 of Arabidopsis thaliana (Q9M8W5)
|1.A.8.10.6||The pollen-specific water/urea aquaporin, Tip1;3 (Soto et al. 2008)||Viridiplantae|
Tip1;3 of Arabidopsis thaliana (O82598)
The pollen-specific water/urea aquaporin. Tip5;1 (Soto et al. 2008) An aquaporin specifically targeted to pollen mitochondria; probably involved in nitrogen remobilization (Soto et al., 2010).
Tip5;1 of Arabidopsis thaliana (Q9STX9)
Aquaporin-B, AqpB of 294 aas and 6 TMSs. Tyr216 in loop D is a key residue in gating, possibly
involving phosphorylation. Mutation of Tyr216 to aspartate or glutamate
initiated water permeability. The truncated, permanently open AqpB yielded
cells with reduced capability to cope with hypotonic stress (von Bülow et al. 2015).
AqpB of Dictyostelium discoideum
|1.A.8.10.9||Aquaporin TIP1-2 (Gamma-tonoplast intrinsic protein 2) (Gamma-TIP2) (Salt stress-induced tonoplast intrinsic protein) (Tonoplast intrinsic protein 1-2) (AtTIP1;2)||Plants||TIP1-2 of Arabidopsis thaliana |
|1.A.8.11.1||Tonoplast intrinsic protein (ωTIP) ||Plants||ωTIP of Pisum sativum (spP25794)|
|1.A.8.11.2||The plasma membrane aquaporin, NtAQP1 (H2O and CO2 permeable; important for photosynthesis, stomatal opening and leaf growth) (Uehlein et al., 2003; Uehlein et al., 2008)||Plants||NtAQP1 of Nicotiana tabacum (CAA04750)|
Plasma membrane aquaporin 1 (Törnroth-Horsefield et al., 2006). Transports H2O, H2O2 (Dynowski et al., 2008), O2 and CO2 (Zwiazek et al. 2017). Forms active heterotetramers with PIP2;1 (1.A.8.11.4); down regulated under drought stress (Najafabadi et al., 2008). Gated by H+, Ca2+, Mn2+ and Cd2+ (Verdoucq et al., 2008). The wheat orthologue has been described (Ayadi et al., 2011). 96% identical to PIP1;3. In Selaginella moellendorffii (Sm; spikemoss), SmPIP1;1 is retained in the ER while SmPIP2;1 is found in the plasma membrane but, upon co-expression, both isoforms are found in the plasma membrane as a heterotetramer, leading to a synergistic effect on water membrane permeability (Bienert et al. 2018). In some speices, PIP1 is inactive (e.g., in maize), but formation of a hetrotetramer with PIP2 allows transport (Vajpai et al. 2018).
PIP1.1 of Arabidopsis thaliana (P61837)
Plasma membrane intrinsic protein 2a (forms active heterotetramers with PIP1;1 (TC# 1.A.8.11.3); down regulated under drought stress (Najafabadi et al., 2008). Transports H2O2 (Dynowski et al., 2008). The Mesembryanthemum crystallinum PIP2;1 orthologue is an aquaporin impermeable to urea and glycerol. It is positively regulated by PKA- and PKC- mediated phosphorylation (Amezcua-Romero et al., 2010). PIP1;1 and PIP2;2 (Q9ATM8) co-expression modulates the membrane water permeability in the halophyte Beta vulgaris storage root through a pH regulatory response, enhancing membrane versatility to adjust its water transfer capacity (Bellati et al., 2010). The wheat orthologue has been described (Ayadi et al., 2011). Inter-TMS interactions occurring both within and between
monomers play crucial roles in tetramer formation, and assembly of tetramers is critical for their trafficking from the ER to the plasma membrane as well as
water permeability (Yoo et al. 2016). This protein as well as 1.A.8.11.6 is possibly orthologous to spinach
PIP1;2 for which the crystal structure is available (PDP# 4JC6) (Berny et al. 2016). Plays a role in drought and salt tolerance (Wang et al. 2015).
PIP2;1 of Arabidopsis thaliana (P43286)
|1.A.8.11.5||Probable aquaporin PIP2-6 (Plasma membrane intrinsic protein 2-6) (AtPIP2;6) (Plasma membrane intrinsic protein 2e) (PIP2e)||Plants||PIP2-6 of Arabidopsis thaliana |
Aquaporin PIP2-8 (Plasma membrane intrinsic protein 2-8) (AtPIP2;8) (Plasma membrane intrinsic protein 3b) (PIP3b). This protein as well as 1.A.8.11.4 are possibly orthologous to spinach PIP1;2 for which the crystal structure is available (PDP# 4JC6) (Berny et al. 2016).
PIP2-8 of Arabidopsis thaliana
Aquaporin PIP2;5 (PIP2-5) of 285 aas. Transports water and hydrogen peroxide (H2O2) (Bienert et al. 2014). PIP1;2 doesn't transport H2O2. TMS3 contains an LxxA motif that targets the protein to the plasma membrane from the ER. While PIP2s are in the plasma mebrane, PIP1s are retained in the ER; this motif only partly explains the difference (Chevalier and Chaumont 2015). PIP1;2 AND PIP2;5 form homo- and heterotetramers (Berny et al. 2016).
PIP2;5 of Zea mays
Aqp2 of 297 aas and 6 TMSs. Induced by both NH3 and CO2, and transports both gases. Aqp2 is found in the plasma membrane and may be involved in photoprotection. It may
facilitate the efflux of NH3, preventing the uncoupling effect of high
intracellular ammonia concentrations (Matsui et al. 2018).
Aqp2 of Phaeodactylum tricornutum, a marine photoautotrophic diatoms
Nodulin-26 aquaporin and glycerol facilitator, NIP (de Paula Santos Martins et al. 2015). Transports NH3 5-fold better than water in Hg2+-sensitive fashion (Hwang et al., 2010).
Nodulin-26 of Glycine max (spP08995)
|1.A.8.12.10||Arsenite export pore, AqpS (Yang et al., 2005)||Bacteria||AqpS of Sinorhizobium meliloti (CAC45655)|
The silicon (silicic acid) (undissociated form) transporter, Lsi1 (Ma et al., 2007a, b; Mitani et al., 2008). The barley orthologue Lsi1 (also called NIP2-1) is also a silicon (silicic acid) uptake channel (Chiba et al., 2009). Rice Lsi1 also transports arsenite and pentavalent mono and dimethyl arsenite (Li et al., 2009). In addition to silicon (Si), selenite (Se) uptake is mediated by Lsi1, also called NIP2;1 (Zhao et al., 2010).
Lsi1 of Oryza sativa (Q6Z2T3)
|1.A.8.12.3||The boric acid channel protein, NIP5;1 (expressed in the root elongation zone and root hairs in response to boron deficiency) (Takano et al., 2006)||Plants||NIP5;1 of Arabidopsis thaliana (NP_192776)|
|1.A.8.12.4||The root-expressed MIP transporter of lactic acid, NIP2;1 (Nod26-like MIP-4; NLM4) (induced by water logging and anoxic stress; shows minimal water and glycerol transport). It may play a role in adaptation to lactic fermentaion under anaerobic stress (Choi and Roberts, 2007). Lactic acid transport is induced by anoxic stress (Choi and Roberts, 2007).||Plants ||NIP2;1 of Arabidopsis thaliana (Q8W037)|
The silicon (silicic acid) transporter, Nip2-2 (Nip2;2) (Mitani et al., 2008). Also transports arsenite (Li et al., 2009).
Nip2-2 of Oryza sativa (Q67WJ8)
Nip7;1 arsenite and borate channel (Isayenkov and Maathuis, 2008; Li et al., 2011)
Nip7. 1 of Arabidopsis thaliana (Q8LAI1)
|1.A.8.12.7||Aquaporin NIP1-2 (NOD26-like intrinsic protein 1-2) (AtNIP1;2) (Nodulin-26-like major intrinsic protein 2) (NodLikeMip2) (Protein NLM2)||Plants||NIP1-2 of Arabidopsis thaliana |
|1.A.8.12.8||Aquaporin NIP1-1 (NOD26-like intrinsic protein 1-1) (AtNIP1;1) (Nodulin-26-like major intrinsic protein 1) (NodLikeMip1) (Protein NLM1)||Plants||NIP1-1 of Arabidopsis thaliana |
|1.A.8.12.9||Aquaporin NIP6-1 (NOD26-like intrinsic protein 6-1) (AtNIP6;1)||Plants||NIP6-1 of Arabidopsis thaliana |
|1.A.8.13.1||MIP family homologue ||Archaea ||Orf of Archaeoglobus fulgidus, AE000782 (ID# AF1426)|
Hg2+-inhibitable aquaporin, AqpM (transports both water and glycerol as well as CO2) (Kozono et al., 2003; Araya-Secchi et al., 2011). Its 3-d structure has been determined to 1.7 Å. In AqpM, isoleucine replaces a key histidine residue found in the lumen of water channels, which becomes a glycine residue in aquaglyceroporins. As a result of this and other side-chain substituents in the walls of the channel, the channel is intermediate in size and exhibits differentially tuned electrostatics when compared with the other subfamilies (Lee et al. 2005).
AqpM of Methanothermobacter marburgensis
Putative aquaporin, GlpF5, of 216 aas; probably transports water, glycerol and dihydroxyacetone (Bienert et al. 2013).
GlpF5 of Lactobacillus plantarum
|1.A.8.2.1||Glycerol facilitator ||Gram-positive bacteria and Haemophilus influenzae ||GlpF of Bacillus subtilis |
Aquaglyceroporin of 270 aas and 6 TMSs.
Aquaporin of Paramecium bursaria chlorella
Mixed function glycerol facilitator/aquaporin, GlpF (Froger et al. 2001).
GlpF of Lactococcus lactis
|1.A.8.2.3||Probable glycerol uptake facilitator protein|
GlpF of Mycoplasma gallisepticum )
GlpF1; transports water, dihydroxyacetone and glycerol as well as D,L-lactic acid (Bienert et al. 2013).
GlpF1 of Lactobacillus plantarum
GlpF2. Transporter of water, dihydroxyacetone and glycerol (Bienert et al. 2013).
GlpF2 of Lactobacillus plantarum
GlpF3. Transports water, dihydroxyacetone and glycerol (Bienert et al. 2013).
GlpF3 of Lactobacillus plantarum
GlpF4. Transports water, dihydroxyacetone and glycerol as well as D,L-lactic acid (Bienert et al. 2013).
GlpF4 of Lactobacillus plantarum
Putative aquaporin, GlpF6. Probably transports water, glycerol and dihydroxyacetone (Bienert et al. 2013).
GlpF6 of Lactobacillus plantarum
Glycerol facilitator, GlpF, of 248 aas and 6 TMSs
GlpF of Blattabacterium sp. subsp. Blattella germanica (strain Bge) (Blattella germanica symbiotic bacterium)
Aquaporin Z water channel (aqpZ gene expression is under sigma S control; induced at the onset of stationary phase) (Mallo and Ashby, 2006). The high resolution 3-d structure is available (PDB 1RC2) revealing two re-entrant coil-helix domains from the selectivity filter (Savage et al. 2003).
AqpZ of E. coli (P60844)
Intracellular endoplasmic reticulum (ER)-localized Aquaporin 11 (Aqp11, AqpX1) water channel (important for the development of kidney proximal tubules; disruption produces neonatally fatal polycystic kidneys (Ishibashi 2006). Has a positively charged C-terminal amino acid cluster similar to the di-lysine motif (-KKXX) for ER retention (Nozaki et al., 2008)). In the horse, AQP3 and AQP11 are involved in the resilience of stallion sperm to withstand cryopreservation (Bonilla-Correal et al. 2017).
Aqp11 of Homo sapiens (Q8NBQ7)
Aquaporin-12A (AQP-12) of 295 aas and probably 7 TMSs with an extra N-terminal TMS. Bears a C-terminal KKXX-like ER retention sequence and is found intracelllularly (Ishibashi 2006). It is expressed in elevated amounts in exocrine glandular cells of the pancreas (Danielsson et al. 2014).
AQP12A of Homo sapiens
Aquaporin 10, Aqp10 of 259 aas and 6 TMSs
Aqp10 of Haemonchus contortus (Barber pole worm)
Aquaporin of 263 aas and 7 TMSs (Stavang et al. 2015).
Aquaporin of the salmon leach, Lepeophtheirus salmonis
Aquaporin of 256 aas with 6 TMSs in a 3 (N-terminus) + 3 TMS (C-terminus) arrangement (Zhou et al. 2018).
Aqp of Blomia tropicalis (mite)
FPS1 glycerol efflux facilitator (important for maintaining osmotic balance during mating-induced yeast cell fusion and for tolerating hypoosmotic shock; also transports arsenite and antimonite). FPS1 is a homotetramer (Beese-Sims et al., 2011). Fps1 is important for osmo-adaptation by regulating intracellular glycerol levels during changes in external osmolarity. Upon high osmolarity conditions, yeast accumulate glycerol by increased production of the osmolyte and by restricting glycerol efflux through Fps1. The extended cytosolic termini of Fps1 contain short domains that are important for regulating glycerol flux through the channel. The transmembrane core of the protein plays an equally important role (Geijer et al., 2012). The MAP kinase, Slt2, physically interacts
with Fps1, and this interaction, dependent on phosphorylation of S537, regulates arsenite uptake (Ahmadpour et al. 2016).
FPS1 protein of Saccharomyces cerevisiae
Fps1 hyperactive orthologue of the S. cerevisiae Fps1 (1.A.8.5.1) (Geijer et al., 2012).
Fps1 of Ashbya gossypii (Q75CI7)
|1.A.8.6.1||Aqy1, aquaporin (mediates H2O efflux during sporulation) (spore maturation) (Sidoux-Walter et al., 2004)||Yeast||Aqy1 of Saccharomyces cerevisiae|
|1.A.8.6.2||Aquaporin-2 Aqy2 (plays a role in reducing surface hydrophobicity promoting cell dispersion during starvation and reproduction)||Yeast||Aqy2 of Saccharomyces chevalieri|
Aquaporin, Aqy1 (PIP2-7 7). The subangstron (0.88Å) structure is available (Kosinska Eriksson et al. 2013). the H-bond donor interactions of the NPA motif''s asparagine residues to
passing water molecules are revealed. A polarized water-water H-bond
configuration is observed within the channel. Four selectivity filter water positions
are too closely spaced to be simultaneously occupied. Strongly correlated
movements break the connectivity of selectivity filter water molecules to other water molecules
within the channel, thereby preventing proton transport via a Grotthuss
Aqy1 of Komagataella pastoris (Pichia pastoris)
Water and CO2 permeable aquaporin, AQP1, of an edible mycorhizal fungus (desert truffles) (Navarro-Ródenas et al. 2012).
AQP1 of Terfezia claveryi
Tobacco X-intrinsic protein (XIP1-1-β). Transports glycerol, urea and boric acid, but not water (Bienert et al., 2011).
XIP1-1 of Nicotiana tomentosiformis (E3UN01)
Potato X intrinsic protein, XIP1. Transports glycerol, urea and boric acid, but not water (Bienert et al., 2011).
XIP1-1 of Solanum tuberosum (E3UMZ6)
Morning glory XIP-1-1-α. Transports glycerol, urea and boric acid, but not water (Bienert et al., 2011).
XIP1 of Ipomoea nil (E3UMZ5)
Major intrinsic protein superfamily, aquaporin-like protein. MIP2, of 247 aas and 6 TMSs.
MIP2 of Chlamydomonas reinhardtii (Chlamydomonas smithii)
Aquaporin 1 (CO2-, O2- and nitrous oxide-permeable and water-selective) (Zwiazek et al. 2017). Aquaporin-1 tunes pain perception by interacting with Na(v)1.8 Na+ channels in dorsal root ganglion neurons (Zhang and Verkman, 2010). It is upregulated in skeletal muscle in muscular dystrophy (Au et al. 2008). AQP1 has been reported to
first insert as a four-helical intermediate, where helices 2 and 4 are not inserted into the membrane.
In a second step this intermediate is folded into a six-helical topology. During this process, the
orientation of the third helix is inverted, and it can shift out the membrane core (Virkki et al. 2014). Its synthesis is regluated by Kruppel-like factor 2 (KLF2; Q9Y5W3) which also interacts directly with Aqp1 (Fontijn et al. 2015). A nanoscale ion pump has been derived artificially from Aqp1 (Decker et al. 2017). Mammalian Aquaporin-1 (AQP1) channels activated by cyclic GMP can carry non-selective monovalent cation currents, selectively blocked by arylsulfonamide compounds AqB007 (IC50 170 muM) and AqB011 (IC50 14 muM). Loop D-domain amino acids activate the channel for ion coductance (Kourghi et al. 2018). Water flux through AQP1s is inhibited by 1 - 10 mμM acetozolaminde (Gao et al. 2006).
Aquaporin 1 (AQP1) of Homo sapiens
Water and urea transporting aquaporin (cockroach) (Herraiz et al., 2011).
Aquaporin of Blatella germanica (G8YY04)
Water channel, Aqp1; inhibited by HgCl2 and tetraethylammonium. Plays a role in water homeostasis during blood feeding and humidity adaptation of A. gambiae, a major mosquito vector of human malaria in Africa (Liu et al., 2011).
Aqp1 of Anopheles gambiae (F2YNF6)
Aquaporin, Aqp1 in the gall fly. Transports water but not glycerol or urea. Promotes freeze-tolerance (Philip et al., 2011).
Aqp1 of Eurosta solidaginis (E4W5Y5)
The Drosophila melanogaster integral protein, DRIP (Ishida et al., 2012).
Aqp, DRIP of Drosophila melanogaster (Q9V5Z7)
|1.A.8.8.14||Lens fiber major intrinsic protein (MIP26) (MP26)||Amphibians|
MIP26 of Rana pipiens
Mercury-sensitive whitefly aquaporin-1 of the specialized filter chamber of the alimentary tract (Mathew et al. 2011).
Aquaporin-1 of Bemisia tabaci
Aquaporin-1 or Aquaporin1, Aqp1, of 258 aas and 6 TMSs. Three Aqp1 isoforms are differentially regluated by the function of the vasotocin
(AVTR) and isotocin (ITR) receptors (Martos-Sitcha et al. 2015). Aqp1aa, one of two isoforms in teleosts, may play a role in spermatogenesis in Cynoglossus semilaevis (Guo et al. 2017).
Aqp1 of Sparus aurata (Gilthead sea bream)
Aquaporin-3, Aqp-3 of 271 aas. Transports water, glycerol, hydrogen peroxide and urea (Geadkaew et al. 2015). AQP3 induces the production of
chemokines such as CCL24 and CCL22 through regulating the amount of cellular H2O2 in M2 polarized
alveolar macrophages, implying a role of AQP3 in asthma (Ikezoe et al. 2016).
Aqp3 of Opisthorchis viverrini (liver fluke)
Aqp-x2 water channel in the luminal epithelium of urinary bladder cells and lungs. Responsive to Vasotocin (AVT) (Shibata et al. 2015).
Aqp-x2 of Xenopus laevis
Contractile vacuole aquaporin of 295 aas and 6 TMSs, Aqp. Shown to transport water, accounting for the high water permeability of the contractile vacuole (Nishihara et al. 2008).
Aqp of Amoeba proteus (Amoeba) (Chaos diffluens)
The lens fiber MIP aquaporin (Aqp0) of B. taurus (forms membrane junctions in vivo and double layered crystals in vitro that resemble the in vivo junctions). The water pore is closed in the in vitro structure (Gonen et al., 2004b). It interacts directly with the intracellular loop of connexin 45.6 via its C-terminal extension (Yu et al., 2005). Forms human cataract lens membranes (Buzhynskyy et al., 2007; Yang et al., 2011). A mutation that causes congenital dominant lens cataracts has been identified (Varadaraj et al. 2008). AqpO catalyzes Zn2+-modulated water permeability as a cooperative tetramer (Nemeth-Cahalan et al., 2007). It transports ascorbic acid (Nakazawa et al., 2011). The Detergent organization around solubilized aquaporin-0 using Small Angle X-ray Scattering has been reported (Berthaud et al., 2012). Aquaporin 0 (AQP0) in the eye lens is truncated by proteolytic cleavage during lens maturation. This truncated AQP0 is no longer a water channel (Berthaud et al. 2015). A mutation that causes congenital dominant lens cataracts has been identified (Varadaraj et al. 2008). Cataractogenesis in MIP mutants are probably caused by defects in MIP gene expression in mice (Takahashi et al. 2017).
Major intrinsic protein (MIP or Aqp0) of Bos taurus
|1.A.8.8.20||Channel protein ||Cyanobacteria ||Copper homeostasis protein (SmpX) of Synechococcus sp. |
Aquaporin x5 of 273 aas and 6 TMSs, Aqp-x5. The sequence reveals a mercurial-sensitive cysteine and a putative phosphorylation motif site for protein kinase A at Ser-257 (Kubota et al. 2006). A swelling assay using Xenopus oocytes revealed that AQP-x5 facilitated water permeability. Expression of AQP-x5 mRNA was restricted to the skin, brain, lungs and testes. Immunofluorescence and immunoelectron microscopical studies using an anti-peptide antibody (ST-156) against the C-terminal region of the AQP-x5 protein revealed the presence of immunopositive cells in the skin, with the label predominately localized in the apical plasma membrane of the secretory cells of the small granular glands. These glands are unique both in being close to the epidermal layer of the skin and in containing mitochondria-rich cells with vacuolar H+-ATPase dispersed among its secretory cells. Results from immunohistochemical experiments on the mucous or seromucous glands of several other anurans verified this result (Kubota et al. 2006).
Aqp-x5 of Xenopus laevis (African clawed frog)
Aqp-1A of 258 aas and 6 TMSs, DRIP1. Transports water but not glycerol or urea. Functions in water homeostasis in many tissues and stages of development (Lu et al. 2018).
Aqp-1A of Chilo suppressalis (Asiatic rice borer moth)
Aqp-2A of 269 aas and 6 TMSs, DRIP2. Transports water but not glycerol
or urea. Functions in water homeostasis in many tissues and stages of
development (Lu et al. 2018).
Aqp-2A of Chilo suppressalis (Asiatic rice borer moth)
Big brain-like protein of 309 aas and 6 probable TMSs, BibL1 (Lind et al. 2017).
BibL1 of the euryhaline bay barnacle, Balanus improvisus (Darwin, 1854) (Amphibalanus improvisus)
Aquaporin 1, AQP1, of 261 aas and 6 TMSs, which selectively transports water (Lind et al. 2017).
AQP1 of the euryhaline bay barnacle Balanus improvisus (Darwin, 1854) (Amphibalanus improvisus)
Aquaporin (Aqp) of 458 aas, 6 N-terminal TMSs and a 200 aa hydrophilic C-terminal domain.
Aqp of Blomia tropicalis (mite)
|1.A.8.8.3||The BIB aquaporin of D. melanogaster (transports ions by a channel mechanism involving E71 in TMS1) (Yool, 2007). ||Animals||Big brain (BIB) of Drosophila melanogaster |
|1.A.8.8.4||Aqp6 aquaporin (also transports NO3- and other anions at acidic pH or in the presence of Hg2+) (Ikeda et al., 2002)||Animals||Aqp6 of Homo sapiens|
Aquaporin-4 (AQP4) is the major water channel in the central nervous system and plays an important role in the brain's water balance, including edema formation and clearance. There are 6 splice variants; the shorter ones assemble into functional, tetrameric square arrays; the longer is palmitoylated on N-terminal cysteyl residues) (Suzuki et al., 2008). The longest, Aqp4e, has a novel N-terminal domain and forms a water channel in the plasma membrane although various shorter variants don't (Moe et al., 2008). AQP4, like AQP0 (1.A.8.8.2), forms water channels but also forms adhesive junctions (Engel et al., 2008) (causes cytotoxic brain swelling in mice (Yang et al., 2008)) Mice lacking Aqp4 have impaired olfactions (Lu et al., 2008). Aqp4 is down regulated in skeletal muscle in muscular dystrophy (Au et al. 2008). The crystal structure is known to 2.8 Å resolution (Tani et al., 2009). The structure reveals 8 water molecules in each of the four channels, supporting a hydrogen-bond isolation mechanism and explains its fast and selective water conduction and proton exclusion (Tani et al., 2009; Cui and Bastien, 2011). It is an important antigen in Neuromyelitis optica (NMO) patients (Kalluri et al., 2011). A connection has been made between AQP4-mediated fluid accumulation and post traumatic syringomyelia (Hemley et al. 2013). AQP4 has increased water
permeability at low pH, and His95 is the pH-dependent gate (Kaptan et al. 2015). Also transports NH3 but not NH4+ (Assentoft et al. 2016). Cerebellar damage following status epilepticus involves down regulation of AQP4 expression (Tang et al. 2017). SUR1-TRPM4 and AQP4 form a complex to increase bulk water influx during astrocyte swelling (Stokum et al. 2017). A mutation, S111T, causes intellectual disability, hearing loss, and progressive gait dysfunction (Berland et al. 2018). As in humans, the chicken ortholog, Aqp4, is found in brain > kidney > stomach (Ramírez-Lorca et al. 2006).
AQP4 of Homo sapiens (P55087)
|1.A.8.8.6||Aqp1 water channel of the sleeping chironomid (functions in water removal during anhydrobiosis, Kikawada et al., 2008).|
Aqp1 of Polypedilum vanderplanki
Aqp2 water channel of the sleeping chironomid (functions in water homeostasis during anhydrobiosis (Kikawada et al., 2008).
Aqp2 of Polypedilum vanderplanki (A5A7P0)
Vasopressin-sensitive aquaporin-2 (Aqp2) in the apical membrane of the renal collecting duct (Fenton et al., 2008). Controls cell volume and thereby influences cell proliferation (Di Giusto et al. 2012). It plays a
key role in concentrating urine. Water reabsorption is regulated by AQP2 trafficking between
intracellular storage vesicles and the apical membrane. This process is tightly controlled by the
pituitary hormone arginine vasopressin, and defective trafficking results in nephrogenic diabetes
insipidus (NDI). The crystal structure of Aqp2 has been solved to 2.75Å (Frick et al. 2014). In terrestrial vertebrates, AQP2 function is generally regulated by arginine-vasopressin to
accomplish key functions in osmoregulation such as the maintenance of body water
homeostasis by a cyclic AMP-independent mechanism (Olesen and Fenton 2017; Martos-Sitcha et al. 2015). AQP2 is expressed in the anterior vaginal wall and fibroblasts, and regulates the expression level of collagen I/III i, suggesting that AQP2 is associated with the pathogenesis of stress urinary incontinence through collagen metabolism during ECM remodeling (Zhang et al. 2017). As in humans, the chicken ortholog, Aqp2, is found only in the kidney (Ramírez-Lorca et al. 2006).
Aqp2 of Homo sapiens (P41181)
Aquaporin 5 (x-ray structure at 2.0 Å resolution (PDB# 3D9S) is available) (Horsefield et al., 2008). Aqp5 is a marker for proliferation and migration of human breast cancer cells (Jung et al., 2011). Plays a role in chronic obstructive pulmonary diseases (COPD) (Zhao et al. 2014). Its expression is regulated by androgens (Pust et al. 2015). As in humans, the chicken ortholog, Aqp5, is found in the intestine, the jejunum, ileum and colon (Ramírez-Lorca et al. 2006).
Aquaporin 5 of Homo sapiens (P55064)
Aquaporin 3. 95% identical to the human orthologue. Poorly permeable to water, but more permeable to glycerol and arsenic trioxide (Palmgren et al. 2017). It is expressed in the plasma membrane of basal epidermal cells in the skin; loss of function prevents skin tumorigenesis and epidermal cell proliferation (Hara-Chikuma and Verkman, 2008). The human orthologue also transports both water and glycerol and is the predominant AQP in skin (Jungersted et al. 2013). It's function is necessary for normal proliferation of colon cancer cells due to glycerol uptake (Li et al. 2016). Aqp3 is implicated in cancer progression to the metastatic state as its function promotes cell migration and cell shape plasticity. Its synthesis is regulated by the AhR (aryl hydrocarbon (pollutant) receptor or dioxin receptor), a transcription factor triggered by environmental pollutants (Bui et al. 2016).
Aquaporin 3 of Rattus norvegicus (P47862)
Aqp9 or Aqp-h9 of 294 aas. Takes up glycerol as well as water, and thereby contributes to freeze tolerance (Hirota et al. 2015). An almost identical orthologue, HC-9 in Dryophytes chrysoscelis (gray treefrog), similarly facilitates glycerol permeability. Both the transcriptional and translational levels of HC-9 change in response to thermal challenges, with a unique increase in liver during freezing and thawing (Stogsdill et al. 2017).
Aqp9 of Hyla japonica
Aqp1 of 304 aas and 6 TMSs; the most abundant transmembrane protein in the tegument of Schistosoma mansoni.
This protein is expressed in all developmental stages and seems to be essential in parasite survival
since it plays a crucial role in osmoregulation, nutrient transport and drug uptake (Figueiredo et al. 2014).
Aqp1 of Schistosoma mansoni (Blood fluke)
Basolateral Aqp3 of 292 aas and 6 TMSs in the frog urinary bladder (Shibata et al. 2015).
Aqp3 of Xenopus laevis
|1.A.8.9.13||Aquaglycerolporin, Aqp (high permeability to ammonium, methylamine, glycerol and water) (Beitz et al., 2004) NH4+/NH3+CH3 transporter (Zeuthen et al., 2006).||Protozoan||Aqp of Plasmodium falciparum (CAC88373)|
Glycerolaquaporin 9, Aqp9 of 295 aas and 6 TMSs. Transports water, glycerol and arsenic trioxide, As2O3 (Palmgren et al. 2017). Primary APL cells express AQP9 significantly (2-3 logs) higher than other acute myeloid leukemia cells (AMLs), explaining their exquisite As2O3 sensitivity (Leung et al. 2007). AQP-7 and AQP-9-mediated glycerol transport in tanycyte cells may be
under hormonal control to use glycerol as an energy source during the
mouse estrus cycle (Yaba et al. 2017). It transports multiple neutral and ionic arsenic species including arsenic trioxide, monomethylarsenous acid (MAs(III)) and dimethylarsenic acid (DMA(V)). It also transports clinically relevant selenium species including monomethylselenic acid (MSeA), especially at acidic pH. FCCP, valinomycin and nigericin do not significantly inhibit MSeA uptake, but AQP9 also transport ionic selenite and lactate, with low efficiency compared with MSeA uptake. Selenite and lactate uptake is pH dependent and inhibited by FCCP and nigericin but not valinomycin. The selenite and lactate uptake via AQP9 can be inhibited by different lactate analogs. AQP9 transport of MSeA, selenite and lactate is inhibited by an AQP9 inhibitor, phloretin, and the AQP9 substrate, arsenite (As(III)) (Geng et al. 2017).
Aqp9 of Homo sapiens
Aquaporin 9, Aqp9, small solute channel 1 of 296 aas and 6 TMSs (Wang and Ye 2016).
Aqp9 of Echinococcus granulosus (Hydatid tapeworm)
Water/glycerol aquaglyceroporin 2, AQP2, of 294 aas and 6 TMSs (Lind et al. 2017).
AQP2 of the euryhaline bay barnacle, Balanus improvisus (Darwin, 1854) (Amphibalanus improvisus)
Glycerol-aquaporin of 332 aas and 6 TMSs (Stavang et al. 2015).
Aqp of the salmon leach, Lepeophtheirus salmonis
Aquaporin of 341 aas and 7 TMSs (Ben Amira et al. 2018).
Aqp of Hypocrea atroviridis (Trichoderma atroviride)
AQP2 (AQP9) of 312 aas and 6 TMSs; transports water, glycerol and urea as well as the drugs, melarsoprol and pentamidine (Schmidt et al. 2018).
AQP2 of Trypanosoma brucei
Aquaporin-9 (Aqp9) (permeable to glycerol, urea, polyols, carbamides, purines, pyrmidines, nucleosides, monocarboxylates, pentavalent methylated arsenicals and the arsenic chemotherapeutic drug, trisenox (McDermott et al., 2009). It is poorly permeable to water and not permeable to β-hydroxybutyrate (Carbrey et al., 2003). (Regulated by CFTR and NHERF1 in response to cyclic AMP (Pietrement et al., 2008)) The 7 Å projection structure and a homology model revealed that pore-lining residues and the hydrophobic edge of the tripathic pore of GlpF (1.A.8.1.1) provide the basis for broad substrate specificity (Viadiu et al., 2007). Important for urea transport in mouse hepatocytes (Jelen et al. 2012). Activation of the PPARα transcription factor results in reduction in the abundance of
AQP9 in periportal hepatocytes, but its activation in the fed state directs glycerol into
glycerolipid synthesis rather than into de novo synthesis of glucose (Lebeck et al. 2015). Azacytidine up-regulates AQP9 and enhances arsenic trioxide (As2O3)-mediated
cytotoxicity in acute myeloid leukemia (AML) (Chau et al. 2015). Human Aqp9 transports hydrogen peroxide (HOOH) (Watanabe et al. 2016).
Aqp9 of Rattus norvegicus (P56627)
Aquaporin of 274 aas and 6 TMSs. See Zhou et al. 2018 for its identification.
Aqp of Blomia tropicalis (mite)
Major aquaglyceroporin, LmAQP1: transports water, glycerol, methylglyoxal, trivalent metalloids such as arsenite and antimonite, dihydroxyacetone and sugar alcohols. Also takes up the activated form or the drug, pentostam. It localizes to the flagellum of the Leishmania promastigotes and is used to regulate volume in response to hypoosmotic stress, functions in osmotaxis) (Figarella et al., 2005; Gourbal et al, 2004).
Aqp1 of Leishmania major (Q6Q1Q6)
Aquaporin 1 (permeable to water, glycerol, dihydroxyacetone and urea) (Uzcategui et al., 2004)
Aqp1 of Trypanosoma brucei (Q6ZXT4)
Aquaporin 10. Present in keratinocytes and the stratum corneum (Jungersted et al. 2013).
Aqp10 of Homo sapiens
Glycerol/water/urea/arsenic trioxide-transporting channel protein, aqaporin 7 or Aqp7, but water is a poor substrate (Palmgren et al. 2017). Present in adipose tissue where it allows glycerol efflux. Defects result in increased accumulation of triglycerides, obesity and adult onset (type 2) diabetes (Lebeck 2014). It may be a drug target for anti-type 2 diabetes (Méndez-Giménez et al. 2018). AQP-7- and AQP-9-mediated glycerol transport in tanycyte cells may be under hormonal control to use glycerol as an energy source during the mouse estrus cycle (Yaba et al. 2017). It may also influence whole body energy metabolism (Iena and Lebeck 2018).
Aqp7 of Homo sapiens
|1.A.8.9.7||Glycerol facilitator, Yf1054c (70.5 kDa protein) (Oliveira et al., 2003)||Yeast ||Yf1054c of Saccharomyces cerevisiae (P43549)|
Glycerol uptake facilitator of 393 aas
Glycerol transporter of Cordyceps militaris (Caterpillar fungus)
Aquaporin/glycerol facilitator of 294 aas and 6 TMSs. May play a role in freeze tolerance (Hirota et al. 2015).
Aqp-9 of Xenopus tropicalis