TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
8.A.23.1.1









Extracellular chaperone protein precursor, Basigin (BSG; CD147). It interacts with MCT1, 3 and 4 (TC# 2.A.1.13.1, 7 and 9, respectively) (Ovens et al., 2010; Halestrap 2012).  May play a role in cancer progression (Kendrick et al. 2016). Silencing of CD147 inhibits hepatic stellate cell activation related to suppressing aerobic glycolysis via hedgehog signaling (Li et al. 2021).

Eukaryota
Metazoa
Basigin precursor of Homo sapiens (P35613)
8.A.23.1.2









Extracellular chaperone protein precursor, Embigin. Interacts with MCT2 (2.A.1.13.5) (Ovens et al., 2010; Halestrap 2012).

Eukaryota
Metazoa
Embigin of Homo sapiens (Q6PCB8)
8.A.23.1.3









Potassium channel associated protein, contactin 2, CNTN2, of 1040 aas and possibly 2 TMSs, at the N- and C-termini.  Mutations are associated with autosomal recessive cortical myoclonic tremors and epilepsy (Stogmann et al. 2013).

Eukaryota
Metazoa
CNTN2 of Homo sapiens
8.A.23.1.4









Canalicular bile acid transporter (C-BAT) ecto-ATPase (GP110)
Eukaryota
Metazoa
C-BAT (GP110) of Rattus norvegicus
8.A.23.1.5









Hepatocyte cell adhesion molecule (CAM) precursor of 416 aas.  Important for interactions, trafficking and function of  ClC2 (CLC-2) in several tissues including the nervious system where it influences human leukodystrophies (Capdevila-Nortes et al. 2015).

Eukaryota
Metazoa
CAM of Homo sapiens
8.A.23.1.6









Fibroblast growth factor receptor-like protein, FGFRL1, of 504 aas and 2 TMSs, one N-terminal and one C-terminal. It is capable of inducing syncytium formation (Steinberg et al. 2010).

Eukaryota
Metazoa
FGFRL-1 of Homo sapiens
8.A.23.1.7









Fibroblast growth factor receptor 1, FGFR1, of822 aas and 2 TMSs, one N-terminal and one central.  FGFR1 is a tyrosine-protein kinase that acts as cell-surface receptor for fibroblast growth factors and plays an essential role in the regulation of embryonic development, cell proliferation, differentiation and migration. Required for normal mesoderm patterning and correct axial organization during embryonic development, normal skeletogenesis and normal development of the gonadotropin-releasing hormone (GnRH) neuronal system (Haenzi and Moon 2017).

FGFR1 of Homo sapiens
8.A.23.1.8









Neuroplastin NptN of 398 aas (Beesley et al. 2014).  Important for targetting of certain transporters such as Xkr8 to the plasma membrane with which it, with basigin, forms a physical complex (Suzuki et al. 2016).

Eukaryota
Metazoa
NptN of Homo sapiens
8.A.23.1.9









Fibroblast growth factor receptor 4, FGFR4, of 802 aas and 2 - 4 TMSs.  Serves as the receptor for FGF23 for the activation of TRP6 (TC# 1.A.4.1.5). Binding activates the TRP6 channel for inorganic cation (including Ca2+) transport (Smith et al. 2017). It also regulates Na+:phosphate co-transport together with α-Klotho (see paragraph 2 in the family description of TC# 1.A.108; Hu et al. 2018).

Eukaryota
Metazoa
FGFR4 of Homo sapiens
8.A.23.1.10









Activated leukocyte cell adhesion molecule, ALCAM or CD166 antigen, of 583 aas and 2 TMSs, N- and C-terminal.  It is expressed on and in the cell membranes of various cells.  In the spinal cord dorsal horn (DH), the first gate for the sensory and pain transmission to the brain, ALCAM plays modulatory roles in the excitatory synaptic transmission and plasticity in the (rat) spinal DH (Park et al. 2017).

Eukaryota
Metazoa
ALCAM of Homo sapiens
8.A.23.1.11









Interleukin 1 receptor of 569 aas and 2 TMSs, N-terminal and near the middle of the protein. It is the receptor for IL1A, IL1B and IL1RN. After binding to interleukin-1, it associates with the coreceptor IL1RAP to form the high affinity interleukin-1 receptor complex which mediates interleukin-1-dependent activation of NF-kappa-B, MAPK and other pathways. Signaling involves the recruitment of adapter molecules such as TOLLIP, MYD88, and IRAK1 or IRAK2 via the respective TIR domains of the receptor/coreceptor subunits. It binds ligands with comparable affinity, and binding of antagonist IL1RN prevents association with IL1RAP to form a signaling complex (Slack et al. 2000).

Eukaryota
Metazoa
IL-1R of Homo sapiens
8.A.23.1.12









cSrc tyr kinase of 536 aas; regulates the Na+,K+-ATPase and connexin 43, probably by direct phosphorylation (Giepmans 2006).

Eukaryota
Metazoa
cSrc of Homo sapiens
8.A.23.1.13









Epidermal growth factor receptor (EGFR) of 1426 aas and 2 or more TMSs.  Binds to four ligands: Spitz, Gurken, Vein and Argos, transducing signals through the ras-raf-MAPK pathway. Involved in a myriad of developmental decisions (Geiger et al. 2011).

Eukaryota
Metazoa
EGFR of Drosophila melanogaster (Fruit fly)
8.A.23.1.14









Coxsackievirus and adenovirus receptor, CAR, of 365 aas and 2 TMSs near the N- and C-termini. It is a component of the epithelial apical junction complex that may function as a homophilic cell adhesion molecule and is essential for tight junction integrity. It is also involved in transepithelial migration of leukocytes through adhesive interactions with JAML, a transmembrane protein of the plasma membrane of leukocytes (Cohen et al. 2001). It's subcellular distribution has been studied (Ifie et al. 2018). The CAR in zebrafish (Q90Y50) has been discussed (Rathjen 2020).

Eukaryota
Metazoa
CAR of Homo sapiens
8.A.23.1.15









Ephrin type-B receptor 4 (EPHB4; EC:2.7.10.1). Alternative name(s): Hepatoma transmembrane kinase; Tyrosine-protein kinase, TYRO11.  It is a receptor tyrosine kinase which binds promiscuously transmembrane ephrin-B family ligands residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells.  It plays a role in postnatal blood vessel remodeling, morphogenesis and permeability (Erber et al. 2006; Martin-Almedina et al. 2016).

Eukaryota
Metazoa
EPHB4 of Homo sapiens
8.A.23.1.16









Angiopoietin-1 receptor of 1072 aas, Tek, a tyrosyl protein kinase (Ward and Dumont 2002).

Eukaryota
Metazoa
Tek of Mus musculus
8.A.23.1.17









Receptor tyrosyl protein kinase, ErbB4 (ErbB-4).  Plays an essential role as cell surface receptor for neuregulins and EGF family members and regulates development of the heart, the central nervous system and the mammary gland, gene transcription, cell proliferation, differentiation, migration and apoptosis (Deng et al. 2013).

Eukaryota
Metazoa
ErbB4 of Homo sapiens
8.A.23.1.18









Tex14 of 1497 aas and 1 or 2 TMSs.  Required both for the formation of intercellular bridges during meiosis and for kinetochore-microtubule attachment during mitosis. Intercellular bridges, called 'ring canals', probably result from nurse cell fusion with the developing oocyte.  They are evolutionarily conserved structures that connect differentiating germ cells and are required for spermatogenesis, oogenesis and male fertility. They act by promoting the conversion of midbodies into intercellular bridges via its interaction with CEP55. Interaction with CEP55 inhibits the interaction between CEP55 and PDCD6IP/ALIX and TSG101, blocking cell abscission and leading to transformation of midbodies into intercellular bridges. In spite of its PK domain, it has no protein kinase activity in vitro (Lei and Spradling 2016).

Eukaryota
Metazoa
Tex14 of Homo sapiens
8.A.23.1.19









The Advanced glycosylation end product-specific receptor of 404 aas and 2 TMSs, N- and C-terminal, AGER or RAGE.  It is the receptor for amyloid beta peptide, and it contributes to the translocation of amyloid-beta peptide (ABPP) across the cell membrane from the extracellular to the intracellular space in cortical neurons. ABPP-initiated RAGE signaling, especially stimulation of p38 mitogen-activated protein kinase (MAPK), has the capacity to drive a transport system delivering ABPP as a complex with RAGE to the intraneuronal space.  RAGE also has a number of other functions (Fang et al. 2010;.Jin et al. 2011). It's structure is known to 1.5 Å resolution (Park et al. 2010; Xue et al. 2011).

;

Eukaryota
Metazoa
RAGE of Homo sapiens
8.A.23.1.20









Polymeric immunoglobulin receptor-like protein, pIgR, of 562 aas and 2 TMSs, one N-terminal and one near the C-terminus of the protein.  It is the receptor for white spot syndrome virus (WSSV) infection (Niu et al. 2019Niu et al. 2019).

Eukaryota
Metazoa
pIgR of Penaeus japonicus (Kuruma prawn) (Marsupenaeus japonicus)
8.A.23.1.21









Polymeric Ig-like receptor of 345 aas and 2 TMSs, pIgR, also called Cell adhesion molecule 4 isoform X2.

Eukaryota
Metazoa
pIgR of Homo sapiens
8.A.23.1.22









Polymeric Ig-like receptor family protein, pIgR, of 774 aas and 1 TMS, near the C-terminus.

Eukaryota
Metazoa
pIgR of Drosophila melanogaster (Fruit fly)
8.A.23.1.23









Poliovirus receptor-related protein 3-like isoform X, PVRL3, of 366 aas and 1 N-terminal TMS

Eukaryota
Metazoa
PVRL3 of Lipotes vexillifer (Yangtze river dolphin)
8.A.23.1.24









Uncharacterized protein of 323 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Metazoa
UP of Strongylocentrotus purpuratus
8.A.23.1.25









T-cell surface antigen CD2 of 351 aas. CD2 interacts with lymphocyte function-associated antigen CD58 (LFA-3) and CD48/BCM1 to mediate adhesion between T-cells and other cell types. CD2 is implicated in the triggering of T-cells,  and the cytoplasmic domain is implicated in the signaling function.

Bacteria
Firmicutes
CD2 of Homo sapiens
8.A.23.1.26









Carcinoembryonic antigen-related cell adhesion molecule 1-like protein of 663 aas and 1 TMS.  This protein appears to be related to members of family 8.A.128, and these two families may comprise a superfamily.

Eukaryota
Metazoa
Adhesin of Xenopus laevis
8.A.23.1.27









TGF-β (Tkv) receptor protein kinase of 575 aas and 1 TMS (Bartoszewski et al. 2004).

Eukaryota
Metazoa
Tkv receptor of Drosophila melanogaster (Fruit fly)
8.A.23.1.28









Neural cell adhesion molecule 2-like protein of 567 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Metazoa
Adhesion protein of Astatotilapia calliptera (eastern happy)
8.A.23.1.29









Receptor tyrosine kinase which plays a central role in the formation and the maintenance of the neuromuscular junction (NMJ), the synapse between the motor neuron and the skeletal muscle (Tan-Sindhunata et al. 2015). Recruitment of AGRIN by LRP4 to the MUSK signaling complex induces phosphorylation and activation of MUSK, the kinase of the complex (Koppel et al. 2019).

Eukaryota
Metazoa
MUSK of Homo sapiens
8.A.23.1.30









Insulin receptor-like tyrosine kinase, DAF2, of 1846 aas and 3 putative TMSs, one near the N-terminus, and two in the C-terminal part ofthe protein. It regulates metabolism, controls longevity and prevents developmental arrest at the dauer stage (Fierro-González et al. 2011; Tiku et al. 2017; Chen et al. 2013). The nematode insulin receptor (IR), DAF-2B, modulates insulin signaling by sequestration of insulin peptides (Martinez et al. 2020).

Eukaryota
Metazoa
DAF2 of Caenorhabditis elegans
8.A.23.1.31









Hemicentin-1-like protein of 321 aas and 0 - 4 TMSs.

Eukaryota
Metazoa
Him1 of Penaeus vannamei
8.A.23.1.32









Self-ligand receptor of the signaling lymphocytic activation molecule (SLAM) family-6, SlamF6, of 351 aas and possibly 3 TMSs, two near the N-terminus, and one near the C-terminus (Togni et al. 2004). SLAM receptors, triggered by homo- or heterotypic cell-cell interactions, modulate the activation and differentiation of a wide variety of immune cells and thus are involved in the regulation and interconnection of both innate and adaptive immune responses (Griewank et al. 2007).

Eukaryota
Metazoa
SlamF6 of Mus musculus (Mouse)
8.A.23.1.33









Nephrin, NPHS1 of 1241 aas and two TMSs, one at the N-terminus, and one near the C-terminus of the protein.  Nephrin forms a complex with podocin (TC# 3.A.16.1.1), CD2AP (8.A.34.1.5) and TRPC6 (1.A.4.1.5) to form a macromolecular assembly that constitutes the slit-diaphragm in podocytes, a tight juntion-like complex (Mulukala et al. 2020).

 

Eukaryota
Metazoa
Nephin of Homo sapiens
8.A.23.1.34









Signal-regulatory protein beta-1, SIRPbeta (SIRPβ) of 398 aas and 2 TMSs, N- and C-terminal.  It is an immunoglobulin-like cell surface receptor involved in the negative regulation of receptor tyrosine kinase-coupled signaling processes, and it participates in the recruitment of tyrosine kinase SYK. It triggers activation of myeloid cells when associated with TYROBP (Dietrich et al. 2000). Positive regulation of phagocytosis by SIRPbeta has been demonstrated as part of  its signaling mechanism in macrophages (Hayashi et al. 2004).

Eukaryota
Metazoa
SIRPβ of Homo sapiens
8.A.23.1.35









Serine/threonine-protein kinase LMTK1 (AATK) of 1374 aas and one N-terminal TMS. It plays a role in axon outgrowth and spine formation (Wei et al. 2020).

Eukaryota
Opisthokonta
LMTK1 of Homo sapiens
8.A.23.1.36









CD48 antigen (BCM1; BLAST1; Sgp-60; MEM102; SLAM family member 2, SLAMF2) of 243 aas with 2 TMSs, N- and C-terminal. It is a ligand for CD2, and may facilitate interaction between activated lymphocytes. It is probably involved in regulating T-cell activation (González-Cabrero et al. 1999).

Eukaryota
Opisthokonta
BCM1 of Homo sapiens
8.A.23.1.37









Platelet-derived growth factor receptor beta, PDGFRB, a tyrosine-protein kinase that acts as a cell-surface receptor for homodimeric PDGFB and PDGFD and for heterodimers formed by PDGFA and PDGFB (Kelly et al. 1991), and plays an essential role in the regulation of embryonic development, cell proliferation, survival, Ca2+ transport, differentiation, chemotaxis and migration (Kazlauskas et al. 1991; Vanlandewijck et al. 2015).

Eukaryota
Opisthokonta
PDGFRB of Homo sapiens
8.A.23.1.38









BDNF/NT-3 growth factors receptor, ofNKRK2 or TrkB, of 822 aas and 1 N-terminal TMS. It is a receptor tyrosine kinase involved in the development and the maturation of the central and the peripheral nervous systems through regulation of neuron survival, proliferation, migration, differentiation, and synapse formation and plasticity. It is a receptor for BDNF/brain-derived neurotrophic factor and NTF4/neurotrophin-4. Alternatively, it can bind NTF3/neurotrophin-3 which is less efficient in activating the receptor but regulates neuron survival through NTRK2 (Haniu et al. 1995, Yeo et al. 2004). Upon ligand-binding, it undergoes homodimerization, autophosphorylation and activation (Yeo et al. 2004).

 

 

 

 

 

 

 

Eukaryota
Opisthokonta
TrkB of Homo sapiens
8.A.23.2.1









T-cell surface glycoprotein, CD4, of 458 aas and 2 TMSs, N- and C-terminal.  It is the receptor for HIV and other viruses (see family description) (Raphael et al. 2020).

Eukaryota
Metazoa
CD4 of Homo sapiens
8.A.23.2.2









CD4-like protein 2 of 429 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Metazoa
CD4 of Ctenopharyngodon idella (grass carp)
8.A.23.2.3









Lymphocyte activation gene 3 protein of 487 aas and 2 TMSs

Eukaryota
Metazoa
Lymphocyte activation protein of Thamnophis elegans (Western garter snake)
8.A.23.2.4









Neural cell adhesion molecule 2-like protein of 496 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Metazoa
Cell adhestion protein of Tachysurus fulvidraco (yellow cat fish)
8.A.23.2.5









Uncharacterized protein of 414 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Metazoa
UP of Colinus virginianus (northern bobwhite)
8.A.23.2.6









CD16A (FcγRIIIA, FCGR3A, FCG3, FCGR3, IGFR3) antiinflamatory protein of 254 aas and 2 TMSs, N- and C-terminal (Ben Mkaddem et al. 2014). It is a receptor for the Fc region of IgG. It binds complexed or aggregated IgG and also monomeric IgG and mediates antibody-dependent cellular cytotoxicity (ADCC) and other antibody-dependent responses, such as phagocytosis (Ferrara et al. 2011, Mizushima et al. 2011).

Eukaryota
Opisthokonta
CD16A of Homo sapiens
8.A.23.2.7









CD16B of 233 aas and 2 TMSs, N- and C-terminal. It may serve as a trap for immune complexes in the peripheral circulation which does not activate neutrophils. Microinflammation status, involving CD16, observed in chronic kidney disease patients is associated with endothelial damage (Ramirez et al. 2007).

Eukaryota
Opisthokonta
CD16B of Homo sapiens
8.A.23.3.1









TMEM25 of 366 aas and up to 4 TMSs, scattered throughout the protein. The expression of the Tmem25 is strongly influenced by glutamate ionotropic receptor kainate type subunit 4, and it is primarily localized to late endosomes in neurons (Zhang et al. 2019). The effects of TMEM25 on neuronal excitability are likely mediated by N-methyl-D-aspartate receptors. TMEM25 affects the expression of the NR2B subunit and interacts with NR2B; both colocalize to late endosome compartments. TMEM25 induces acidification changes in lysosome compartments and accelerates the degradation of NR2B, and TMEM25 expression is decreased in brain tissues from patients with epilepsy and epileptic mice. TMEM25 overexpression attenuated the behavioral phenotypes of epileptic seizures, whereas TMEM25 downregulation exerted the opposite effect (Zhang et al. 2019).

Eukaryota
Metazoa
TMEM25 of Homo sapiens
8.A.23.3.2









TMEM25-like protein, isoform X3 of 169 aas and 1 TMS.

Eukaryota
Metazoa
TMEM25 of Pteropus alecto
8.A.23.3.3









TMEM25 protein of 279 aas and 1 TMS. It may be an incomplete sequence.

Eukaryota
Metazoa
TMEM25 of Neopelma chrysocephalum (saffron-crested tyrant-manakin)
8.A.23.4.1









Intercellular adhesion molecule 1, ICAM-1 or ICAM1, of 532 aas and 2 TMSs, N- and C-terminal. During leukocyte trans-endothelial migration, ICAM1 engagement promotes the assembly of endothelial apical cups (Hayashi et al. 2001; van Buul et al. 2007). STAT3-dependent transcriptional regulation of ICAM-1, an endothelial transmembrane protein, regulates vascular permeability in endothelial cells (Wang et al. 2020).

 

Eukaryota
Opisthokonta
ICAM1 of Homo sapiens
8.A.23.4.2









Vascular cell adhesion protein 1-like protein of 677 aas and probably two TMSs, N- and C-terminal.

Eukaryota
Opisthokonta
Vascular cell adhesion protein 1 of Bufo bufo (common toad)
8.A.23.4.3









Hemicentin-1 of 590 aas and possibly two TMSs, one N-terminal and one near the C-terminus of the protein. Hemicentins are conserved extracellular matrix proteins discovered in Caenorhabditis elegans, with orthologs in all vertebrate species including humans (Vogel et al. 2006).

Eukaryota
Opisthokonta
Hemicentin 1 of Sander lucioperca (pikeperch)
8.A.23.5.1









Programmed cell death 1 ligand 1, PDL1, CD274, B7H1, PDCD1L1, or PDCD1LG1, of 290 aas and 2 TMSs, one N-terminal and one C-terminal. It plays a role in induction of immune tolerance to self. It plays a critical role in induction and maintenance of immune tolerance to self (Freeman et al. 2000, Burr et al. 2017, Mezzadra et al. 2017). As a ligand for the inhibitory receptor PDCD1/PD-1, it modulates the activation threshold of T-cells and limits T-cell effector responses. Several forms of PD-L1 exist expressed on the plasma membrane (mPD-L1), at the surface of secreted cellular exosomes (exoPD-L1), in cell nuclei (nPD-L1), or as a circulating, soluble protein (sPD-L1) (Bailly et al. 2021). The membrane, exosomal and soluble forms of PD-L1 are parts of the highly dynamic PD-1/PD-L1 signaling pathway.

 

 

Eukaryota
Opisthokonta
PD-L1 of Homo sapiens
8.A.23.5.2









V-set domain-containing T-cell activation inhibitor 1 of 282 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Opisthokonta
V-set domain containing protein of Pteropus giganteus (Indian flying fox)
8.A.23.5.3









Butyrophilin-like protein 2 of 487 aas and 2 TMSs, N- and C-terminal.

Eukaryota
Opisthokonta
Butyrophilin of Lynx canadensis (canadian lynx)