TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*1.A.8.1.1









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).

Bacteria
Proteobacteria
GlpF of E. coli
*1.A.8.2.1









Glycerol facilitator
Bacteria
Firmicutes
GlpF of Bacillus subtilis
*1.A.8.2.2









Mixed function glycerol facilitator/aquaporin, GlpF (Froger et al. 2001).

Bacteria
Firmicutes
GlpF of Lactococcus lactis
*1.A.8.2.3









Probable glycerol uptake facilitator protein
Bacteria
Tenericutes
GlpF of Mycoplasma gallisepticum )
*1.A.8.2.4









GlpF1; transports water, dihydroxyacetone and glycerol as well as D,L-lactic acid (Bienert et al. 2013).

Bacteria
Firmicutes
GlpF1 of Lactobacillus plantarum
*1.A.8.2.5









GlpF2.  Transporter of water, dihydroxyacetone and glycerol (Bienert et al. 2013).

Bacteria
Firmicutes
GlpF2 of Lactobacillus plantarum
*1.A.8.2.6









GlpF3.  Transports water, dihydroxyacetone and glycerol (Bienert et al. 2013).

Bacteria
Firmicutes
GlpF3 of Lactobacillus plantarum
*1.A.8.2.7









GlpF4.  Transports water, dihydroxyacetone and glycerol as well as D,L-lactic acid (Bienert et al. 2013).

Bacteria
Firmicutes
GlpF4 of Lactobacillus plantarum
*1.A.8.2.8









Putative aquaporin, GlpF6.  Probably transports water, glycerol and dihydroxyacetone (Bienert et al. 2013).

Bacteria
Firmicutes
GlpF6 of Lactobacillus plantarum
*1.A.8.2.9









Glycerol facilitator, GlpF, of 248 aas and 6 TMSs

Bacteria
Bacteroidetes
GlpF of Blattabacterium sp. subsp. Blattella germanica (strain Bge) (Blattella germanica symbiotic bacterium)
*1.A.8.3.1









Aquaporin Z water channel (aqpZ gene expression is under sigma S control; induced at the onset of stationary phase) (Mallo and Ashby, 2006)

Bacteria
Proteobacteria
AqpZ of E. coli (P60844)
*1.A.8.4.1









Aquaporin 11 (Aqp11) transporter (important for the development of kidney proximal tubules (Nozaki et al., 2008)).

Eukaryota
Metazoa
Aqp11 of Homo sapiens (Q8NBQ7)
*1.A.8.4.2









Aquaporin-12A (AQP-12) of 295 aas and probably 7 TMSs. Expressed in elevated amounts in exocrine glandular cells of the pancreas (Danielsson et al. 2014).

Eukaryota
Metazoa
AQP12A of Homo sapiens
*1.A.8.4.3









Aquaporin 10, Aqp10 of 259 aas and 6 TMSs

Eukaryota
Metazoa
Aqp10 of Haemonchus contortus (Barber pole worm)
*1.A.8.5.1









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).

Eukaryota
Fungi
FPS1 protein of Saccharomyces cerevisiae
*1.A.8.5.2









Fps1 hyperactive orthologue of the S. cerevisiae Fps1 (1.A.8.5.1) (Geijer et al., 2012).

Eukaryota
Fungi
Fps1 of Ashbya gossypii (Q75CI7)
*1.A.8.6.1









Aqy1, aquaporin (mediates H2O efflux during sporulation) (spore maturation) (Sidoux-Walter et al., 2004)
Eukaryota
Fungi
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)
Eukaryota
Fungi
Aqy2 of Saccharomyces chevalieri
*1.A.8.6.3









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 mechanism.

Eukaryota
Fungi
Aqy1 of Komagataella pastoris (Pichia pastoris)
*1.A.8.6.4









Water and CO2 permeable aquaporin, AQP1, of an edible mycorhizal fungus (desert truffles) (Navarro-Ródenas et al. 2012).

Eukaryota
Fungi
AQP1 of Terfezia claveryi
*1.A.8.7.1









Tobacco X-intrinsic protein (XIP1-1-β). Transports glycerol, urea and boric acid, but not water (Bienert et al., 2011).

Eukaryota
Viridiplantae
XIP1-1 of Nicotiana tomentosiformis (E3UN01)
*1.A.8.7.2









Potato X intrinsic protein, XIP1.  Transports glycerol, urea and boric acid, but not water (Bienert et al., 2011).

Eukaryota
Viridiplantae
XIP1-1 of Solanum tuberosum (E3UMZ6)
*1.A.8.7.3









Morning glory XIP-1-1-α. Transports glycerol, urea and boric acid, but not water (Bienert et al., 2011).

Eukaryota
Viridiplantae
XIP1 of Ipomoea nil (E3UMZ5)
*1.A.8.7.4









Major intrinsic protein superfamily, aquaporin-like protein. MIP2, of 247 aas and 6 TMSs.

Eukaryota
Viridiplantae
MIP2 of Chlamydomonas reinhardtii (Chlamydomonas smithii)
*1.A.8.8.1









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).

Eukaryota
Metazoa
Aquaporin 1 (AQP1) of Homo sapiens
*1.A.8.8.2









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).

Eukaryota
Metazoa
Major intrinsic protein (MIP or Aqp0) of Bos taurus
*1.A.8.8.3









The BIB aquaporin of D. melanogaster (transports ions by a channel mechanism involving E71 in TMS1) (Yool, 2007).
Eukaryota
Metazoa
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)
Eukaryota
Metazoa
Aqp6 of Homo sapiens
*1.A.8.8.5









Aquaporin-4 (AQP4) (2 splice variants; the shorter assembles into functional, tetrameric square arrays; the longer is palmitoylated on N-terminal cysteyl residues) (Suzuki et al., 2008). Six splice variants have been identified. The longest, Aqp4e, has a novel N-terminal domain and forms a water channel in the plasma membrane. 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).

Eukaryota
Metazoa
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).
Eukaryota
Metazoa
Aqp1 of Polypedilum vanderplanki
(A5A7N9)
*1.A.8.8.7









Aqp2 water channel of the sleeping chironomid (functions in water homeostasis during anhydrobiosis (Kikawada et al., 2008).

Eukaryota
Metazoa
Aqp2 of Polypedilum vanderplanki (A5A7P0)
*1.A.8.8.8









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).

Eukaryota
Metazoa
Aqp2 of Homo sapiens (P41181)
*1.A.8.8.9









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 (Zhao et al. 2014).  Its expression is regulated by androgens (Pust et al. 2015).

Eukaryota
Metazoa
Aquaporin 5 of Homo sapiens (P55064)
*1.A.8.8.10









Water and urea transporting aquaporin (cockroach) (Herraiz et al., 2011).

Eukaryota
Metazoa
Aquaporin of Blatella germanica (G8YY04)
*1.A.8.8.11









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).

Eukaryota
Metazoa
Aqp1 of Anopheles gambiae (F2YNF6)
*1.A.8.8.12









Aquaporin, Aqp1 in the gall fly. Transports water but not glycerol or urea. Promotes freeze-tolerance (Philip et al., 2011).

Eukaryota
Metazoa
Aqp1 of Eurosta solidaginis (E4W5Y5)
*1.A.8.8.13









The Drosophila melanogaster integral protein, DRIP (Ishida et al., 2012).

Eukaryota
Metazoa
Aqp, DRIP of Drosophila melanogaster (Q9V5Z7)
*1.A.8.8.14









Lens fiber major intrinsic protein (MIP26) (MP26)
Eukaryota
Metazoa
MIP26 of Rana pipiens
*1.A.8.8.15









Mercury-sensitive whitefly aquaporin-1 of the specialized filter chamber of the alimentary tract (Mathew et al. 2011).

Eukaryota
Metazoa
Aquaporin-1 of Bemisia tabaci
*1.A.8.8.16









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).

Eukaryota
Metazoa
Aqp1 of Sparus aurata (Gilthead sea bream)
*1.A.8.8.17









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).

Eukaryota
Metazoa
Aqp3 of Opisthorchis viverrini (liver fluke)
*1.A.8.8.18









Aqp-x2 water channel in the luminal epithelium of urinary bladder cells and lungs.  Responsive to Vasotocin (AVT) (Shibata et al. 2015).

Eukaryota
Metazoa
Aqp-x2 of Xenopus laevis
*1.A.8.8.19









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).

Eukaryota
Amoebidae
Aqp of Amoeba proteus (Amoeba) (Chaos diffluens)
*1.A.8.8.20









Channel protein
Bacteria
Cyanobacteria
Copper homeostasis protein (SmpX) of Synechococcus sp.
*1.A.8.9.1









Aquaporin 3.  Permeable to water and glycerol and 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).

Eukaryota
Metazoa
Aquaporin 3 of Rattus norvegicus (P47862)
*1.A.8.9.2









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).

Eukaryota
Metazoa
Aqp9 of Rattus norvegicus (P56627)
*1.A.8.9.3









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).

Eukaryota
Kinetoplastida
Aqp1 of Leishmania major (Q6Q1Q6)
*1.A.8.9.4









Aquaporin 1 (permeable to water, glycerol, dihydroxyacetone and urea) (Uzcategui et al., 2004)

Eukaryota
Kinetoplastida
Aqp1 of Trypanosoma brucei (Q6ZXT4)
*1.A.8.9.5









Aquaporin 10.  Present in keratinocytes and the stratum corneum (Jungersted et al. 2013).

Eukaryota
Metazoa
Aqp10 of Homo sapiens
*1.A.8.9.6









Glycerol/water/urea channel protein, aqaporin 7 or Aqp7.  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). 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).

Eukaryota
Metazoa
Aqp7 of Homo sapiens
*1.A.8.9.7









Glycerol facilitator, Yf1054c (70.5 kDa protein) (Oliveira et al., 2003)
Eukaryota
Fungi
Yf1054c of Saccharomyces cerevisiae (P43549)
*1.A.8.9.8









Glycerol uptake facilitator of 393 aas

Eukaryota
Fungi
Glycerol transporter of Cordyceps militaris (Caterpillar fungus)
*1.A.8.9.9









Aquaporin/glycerol facilitator of 294 aas and 6 TMSs.  May play a role in freeze tolerance (Hirota et al. 2015).

Eukaryota
Metazoa
Aqp-9 of Xenopus tropicalis
*1.A.8.9.10









Aqp9 or Aqp-h9 of 294 aas.  Takes up glycerol and thereby contributes to freeze tolerance (Hirota et al. 2015).

Eukaryota
Metazoa
Aqp9 of Hyla japonica
*1.A.8.9.11









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).

Eukaryota
Metazoa
Aqp1 of Schistosoma mansoni (Blood fluke)
*1.A.8.9.12









Basolateral Aqp3 of 292 aas and 6 TMSs in the frog urinary bladder (Shibata et al. 2015).

Eukaryota
Metazoa
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).
Eukaryota
Apicomplexa
Aqp of Plasmodium falciparum (CAC88373)
*1.A.8.9.14









Glycerolaquaporin 9, Aqp9 of 295 aas and 6 TMSs.  Transports water, glycerol and arsenic trioxide, As2O3. Primary APL cells expressed AQP9 significantly (2-3 logs) higher than other acute myeloid leukemias (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).

Eukaryota
Metazoa
Aqp9 of Homo sapiens
*1.A.8.9.15









Aquaporin 9, Aqp9, small solute channel 1 of 296 aas and 6 TMSs (Wang and Ye 2016). 

Eukaryota
Metazoa
Aqp9 of Echinococcus granulosus (Hydatid tapeworm)
*1.A.8.10.1









Tonoplast intrinsic protein
Eukaryota
Viridiplantae
TIP of Arabidopsis thaliana (P26587)
*1.A.8.10.2









Tonoplast intrinsic protein-a (transports water, urea, glycerol and gases (CO2 and NH3)
Eukaryota
Viridiplantae
TIPa of Nicotiana tabacum (Q9XG70)
*1.A.8.10.3









Tonoplast intrinsic protein 1.1 (permeable to water and H2O2)
Eukaryota
Viridiplantae
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)].
Eukaryota
Viridiplantae
TIP2;3 of Arabidopsis thaliana (Q9FGL2)
*1.A.8.10.5









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).

Eukaryota
Viridiplantae
SIP1;1 of Arabidopsis thaliana (Q9M8W5)
*1.A.8.10.6









The pollen-specific water/urea aquaporin, Tip1;3 (Soto et al. 2008)
Eukaryota
Viridiplantae
Tip1;3 of Arabidopsis thaliana (O82598)
*1.A.8.10.7









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).

Eukaryota
Viridiplantae
Tip5;1 of Arabidopsis thaliana (Q9STX9)
*1.A.8.10.8









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).

Eukaryota
Dictyosteliida
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)
Eukaryota
Viridiplantae
TIP1-2 of Arabidopsis thaliana
*1.A.8.10.10









Aquaporin TIP2-1 (Delta-tonoplast intrinsic protein) (Delta-TIP) (Tonoplast intrinsic protein 2-1) (AtTIP2;1)
Eukaryota
Viridiplantae
TIP2-1 of Arabidopsis thaliana
*1.A.8.10.11









Probable aquaporin TIP-type alpha (Alpha TIP) (Tonoplast intrinsic protein alpha)
Eukaryota
Viridiplantae
TIPA_PHAVU of Phaseolus vulgaris
*1.A.8.10.12









Aquaporin SIP2-1 (OsSIP2;1) (Small basic intrinsic protein 2-1)
Eukaryota
Viridiplantae
SIP2-1 of Oryza sativa subsp. japonica
*1.A.8.10.13









Aquaporin
Eukaryota
Fungi
AQP of Enterocytozoon bieneusi
*1.A.8.10.14









Uncharacterized protein of 295 aas and 6 TMSs.

Eukaryota
Viridiplantae
UP of Volvox carteri
*1.A.8.10.15









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).

Eukaryota
Metazoa
Aqp8 of Homo sapiens (O94778)
*1.A.8.10.16









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).

Eukaryota
Metazoa
Aqp8a.1 of Danio rerio (Zebrafish) (Brachydanio rerio)
*1.A.8.11.1









Tonoplast intrinsic protein (ωTIP)
Eukaryota
Viridiplantae
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)
Eukaryota
Viridiplantae
NtAQP1 of Nicotiana tabacum (CAA04750)
*1.A.8.11.3









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.

Eukaryota
Viridiplantae
PIP1.1 of Arabidopsis thaliana (P61837)
*1.A.8.11.4









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).

Eukaryota
Viridiplantae
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)
Eukaryota
Viridiplantae
PIP2-6 of Arabidopsis thaliana
*1.A.8.11.6









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).

Eukaryota
Viridiplantae
PIP2-8 of Arabidopsis thaliana
*1.A.8.11.7









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).

Eukaryota
Viridiplantae
PIP2;5 of Zea mays
*1.A.8.12.1









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).

Eukaryota
Viridiplantae
Nodulin-26 of Glycine max (spP08995)
*1.A.8.12.2









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).

Eukaryota
Viridiplantae
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)
Eukaryota
Viridiplantae
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).
Eukaryota
Viridiplantae
NIP2;1 of Arabidopsis thaliana (Q8W037)
*1.A.8.12.5









The silicon (silicic acid) transporter, Nip2-2 (Nip2;2) (Mitani et al., 2008). Also transports arsenite (Li et al., 2009).

Eukaryota
Viridiplantae
Nip2-2 of Oryza sativa (Q67WJ8)
*1.A.8.12.6









Nip7;1 arsenite and borate channel (Isayenkov and Maathuis, 2008; Li et al., 2011)

Eukaryota
Viridiplantae
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)
Eukaryota
Viridiplantae
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)
Eukaryota
Viridiplantae
NIP1-1 of Arabidopsis thaliana
*1.A.8.12.9









Aquaporin NIP6-1 (NOD26-like intrinsic protein 6-1) (AtNIP6;1)
Eukaryota
Viridiplantae
NIP6-1 of Arabidopsis thaliana
*1.A.8.12.10









Arsenite export pore, AqpS (Yang et al., 2005)
Bacteria
Proteobacteria
AqpS of Sinorhizobium meliloti (CAC45655)
*1.A.8.13.1









MIP family homologue
Archaea
Euryarchaeota
Orf of Archaeoglobus fulgidus, AE000782 (ID# AF1426)
*1.A.8.13.2









Hg2+-inhibitable aquaporin, AqpM (transports both water and glycerol as well as CO2) (Kozono et al., 2003; Araya-Secchi et al., 2011). 

Archaea
Euryarchaeota
AqpM of Methanothermobacter marburgensis
*1.A.8.13.3









Putative aquaporin, GlpF5, of  216 aas; probably transports water, glycerol and dihydroxyacetone (Bienert et al. 2013).

Bacteria
Firmicutes
GlpF5 of Lactobacillus plantarum