TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*9.B.87.1.1









Low density lipoprotein receptor-related protein 2 precursor (Megalin - 4660aas; glycoprotein 330) [required for SelP uptake in kidney]. May take up cadmium-metallothionein complexes via receptor-mediated endocytosis (Thévenod, 2010).

Eukaryota
Metazoa
Megalin of Mus musculus (A2ARV4)
*9.B.87.1.2









The EGF-like domain-containing protein of 1918 aas.

Eukaryota
Dictyosteliida
EGF-like domain protein of Dictyostelium discoideum
*9.B.87.1.3









Uncharacterized protein of 270 aas.

Eukaryota
Viridiplantae
UP of Chlorella variabilis (Green alga)
*9.B.87.1.4









Viruses
Poxviridae
EGF-like protein of Variola (smallpox) virus
*9.B.87.1.5









Uncharacterized protein of 3499 aas and 2 TMSs.

Eukaryota
Metazoa
UP of Tetraodon nigroviridis
*9.B.87.1.6









Uncharacterized protein of 628 aas and 2 TMSs

Eukaryota
Viridiplantae
UP of Picea sitchensis
*9.B.87.1.7









Putative vacuolar sorting receptor protein homologue of 631 aas and 2 TMSs

Eukaryota
Viridiplantae
Vacuolar sorting receptor of Oryza sativa
*9.B.87.1.8









Integrin β-1 (ITGB1, FNRB, MDF2, MSK12) of 798 aas and 2 TMSs, N- and C-termini, is a collagen receptor.  Inhibition of endothelial cell migration by thrombospondin-1 type-1 repeats is mediated by beta1 integrins (Short et al. 2005). Integrin beta1 interacts with integrins α1 - 11 to form receptors for fibronectin, laminin, several bacteria and viruses and many other extracellular proteins, and it facilitates sperm-egg fusion (Paul et al. 2015).

Eukaryota
Metazoa
ITGB1 of Homo sapiens
*9.B.87.1.9









Low density lipoprotein receptor, Apolipoprotein E receptor 2 (ApoER2; 996aas) [required for SelP uptake in brain and testis, but not kidney].
Eukaryota
Metazoa
ApoER2 of Mus musculus (Q924X6)
*9.B.87.1.10









Lipophorin receptor of 881 aas, LpR2 (Tufail and Takeda 2009).

Eukaryota
Metazoa
LpR2 of Bombyx mori
*9.B.87.1.11









Crumbs, Crb of 2146 aas and 2 TMSs at the N- and C-termini.  Plays a central role in cell polarity establishment. Participates in the assembly, positioning and maintenance of adherens junctions via its interaction with the SAC complex. Controls the coalescence of the spots of zonula adherens (ZA) into a adhesive ring around the cells (Tepass et al. 1990).

Eukaryota
Metazoa
Crumbs of Drosophila melanogaster
*9.B.87.1.12









Neurogenic locus Notch homolog protein 1, NOTCH of 2,555 aas and 2 TMSs, one N-terminal and one nearer the C-terminus.  Functions as a receptor for membrane-bound ligands Jagged1, Jagged2 and Delta1 to regulate cell-fate determination. Upon ligand activation through the released notch intracellular domain (NICD), it forms a transcriptional activator complex with RBPJ/RBPSUH and activates genes of the enhancer of split locus. It affects the implementation of differentiation, proliferation and apoptotic programs (Brütsch et al. 2010). NOTCH is a schizophrenia gene (Sundararajan et al. 2018). The NOTCH1 signalling pathway regulates vascular barrier function, driving assembly of adherens junction and vascular barrier functions (Polacheck et al. 2017).

 

Eukaryota
Metazoa
Notch of Homo sapiens
*9.B.87.1.13









The BP80 vacuolar sorting receptor of 623 aas and two (N- and C-terminal) TMSs (daSilva et al. 2006). BP80 is a vacuolar sorting receptor for soluble proteins and has a cytosolic domain essential for its intracellular trafficking between the trans-Golgi network and the prevacuole (Saint-Jean et al. 2010).

Eukaryota
Viridiplantae
BP80 of Arabidopsis thaliana (Mouse-ear cress)
*9.B.87.1.14









Low-density lipoprotein receptor-related protein 2, LRP2, of 4630 aas and 1 TMS. Also called the multiligand endocytic receptor. Acts together with CUBN to mediate endocytosis of high-density lipoproteins and is responsible for receptor-mediated uptake of polybasic drugs such as aprotinin, aminoglycosides and polymyxin B. In the kidney, it mediates the tubular uptake and clearance of leptin, and transports leptin across the blood-brain barrier through endocytosis at the choroid plexus epithelium. Endocytosis of leptin in neuronal cells is required for hypothalamic leptin signaling and leptin-mediated regulation of feeding and body weight. It also mediates endocytosis and subsequent lysosomal degradation of CST3 in kidney proximal tubule cells, and catalyzes renal uptake of 25-hydroxyvitamin D3 in complex with the vitamin D3 transporter GC/DBP. It is also involved in the renal uptake of metallothionein-bound heavy metals (Klassen et al. 2004). Together with CUBN, it mediates renal reabsorption of myoglobin as well as renal uptake and subsequent lysosomal degradation of APOM while playing a role in kidney selenium homeostasis by facilitating renal endocytosis of selenoprotein SEPP1. It similarly mediates renal uptake of the antiapoptotic protein BIRC5/survivin which may be important for functional integrity of the kidney (Jobst-Schwan et al. 2013).

Eukaryota
Metazoa
LRP2 of Homo sapiens
*9.B.87.1.15









CFEM domain containing protein of 464 aas and possibly 2 TMSs, N- and C-terminal.

Eukaryota
Fungi
CFEM containing protein of Beauveria bassiana (White muscardine disease fungus) (Tritirachium shiotae)
*9.B.87.1.16









Pro-low-density lipoprotein receptor-related protein 1, pro-LRP1, of 4544 aas and 2 TMSs, one at the N-terminus, and one near the C-terminus.  It is an endocytic receptor involved in endocytosis, in phagocytosis of apoptotic cells, in early embryonic development, and in cellular lipid homeostasis. It may modulate cellular events, such as APP metabolism, kinase-dependent intracellular signaling, neuronal calcium signaling as well as neurotransmission (May et al. 2002, Kinoshita et al. 2003, May and Herz 2003). It acts as an alpha-2-macroglobulin receptor (Klar et al. 2015).and serves as a receptor for Pseudomonas aeruginosa exotoxin A (Kounnas et al. 1992). It modulates APP transport and processing (Eggert et al. 2018).

 

Eukaryota
Metazoa
por-LUP1 of Homo sapiens
*9.B.87.1.17









Sortilin-related protein, SorL1 or SorLA, of 2214 aas and 2 TMSs, N- and C-terminal.  It is a multifunctional endocytic receptor, that may be implicated in the uptake of lipoproteins and of proteases. It also binds LDL, the major cholesterol-carrying lipoprotein of plasma, and transports it into cells by endocytosis (Andersen et al. 2005). This protein contains a large domain that is homologous to several proteins in TC family 9.A.63.

Eukaryota
Metazoa
SorLA of Homo sapiens
*9.B.87.1.18









SPO-spondin of 5150 aas.  It is involved in the modulation of neuronal aggregation and may be involved in developmental events during the formation of the central nervous system.

Eukaryota
Metazoa
SPO-spondin of Homo sapiens
*9.B.87.1.19









Tenurin-1(TENM1, Tnm1, Odz1) of 2725 aas and 1 TMS near but not at the N-terminus. Possibly additional TMSs are present C-terminal to this one, but this is speculative. It is involved in neural development, regulating the establishment of proper connectivity within the nervous system, and may function as a cellular signal transducer (Silva et al. 2011).

Eukaryota
Metazoa
TENM1 of Homo sapiens
*9.B.87.1.20









Tenurin-2 (TENM2, Tnm2, Odz2, latrophilin, LPH1) of 2774 aas and 1 TMS near but not at the N-terminus. Possibly additional TMSs are present C-terminal to this one, but this is speculative. It is involved in neural development, regulating the establishment of proper connectivity within the nervous system, and may function as a cellular signal transducer (Silva et al. 2011). The carboxy-terminal peptide regions of the teneurins plays a role in neuronal function and behavior in mammals (Hogg et al. 2019). LPH1 is presynaptic, whereas Lasso, its high affinity ligand, is postsynaptic. A C-terminal fragment of Lasso interacts with LPH1 and induces Ca2+ signals in presynaptic boutons of hippocampal neurons and in neuroblastoma cells expressing LPH1. Thus, LPH1 and Lasso form transsynaptic complexes capable of inducing presynaptic Ca2+ signals, which affect synaptic functions (Silva et al. 2011).

 

Eukaryota
Metazoa
Tenurin-2 of Homo sapiens
*9.B.87.1.21









Low-density lipoprotein receptor-related-protein 13, Lrp13, of 1355 aas (Gao et al. 2020).

Eukaryota
Metazoa
Lrp13 of Danio rerio (Zebrafish) (Brachydanio rerio)
*9.B.87.1.22









Scavenger receptor/homing receptor stabilin-1 (FEEL-1/CLEVER-1) of 2570 aas and at least 3 TMSs, one N-terminal, and two C-terminal (Adachi and Tsujimoto 2002). It acts as a scavenger receptor for acetylated low density lipoprotein and binds to both Gram-positive and Gram-negative bacteria, possibly playing a role in defense against bacterial infection (Prevo et al. 2004). When inhibited in endothelial tube formation assays, there is a marked decrease in cell-cell interactions, suggesting a role in angiogenesis. It is also involved in the delivery of newly synthesized CHID1/SI-CLP from the biosynthetic compartment to the endosomal/lysosomal system (Kzhyshkowska et al. 2006).

 

Eukaryota
Metazoa
Stabilin-1 of Homo sapiens (Human)
*9.B.87.1.23









Flagellar pocket receptor, cysteine-rich, acidic integral membrane protein, CRAM, of 945 aas with 1 C-terminal TMS and many repeat sequences. It may function as cell surface receptor involved in receptor-mediated endocytosis. Clathrin-dependent targeting is responsible for its localization to the flagellar pocket of the procyclic-form of Trypanosoma brucei (Hung et al. 2004).

 

Eukaryota
Euglenozoa
CRAM of Trypanosoma brucei.
*9.B.87.1.24









Low-density lipoprotein receptor-related protein 4, LRP4, of 1905 aas and 2 TMSs, one N-terminal and one C-terminal. It plays a key role in the formation and the maintenance of the neuromuscular junction (NMJ), the synapse between motor neuron and skeletal muscle. It directly binds AGRIN and recruits it to the MUSK signaling complex to mediates the AGRIN-induced phosphorylation of MUSK, the kinase of the complex. The activation of MUSK in myotubes induces the formation of NMJ by regulating different processes including the transcription of specific genes and the clustering of AChR in the postsynaptic membrane. More generally, has been proposed to function as a cell surface endocytic receptor, binding and internalizing extracellular ligands for degradation by lysosomes (Leupin et al. 2011; Nishimune and Shigemoto 2018).

Eukaryota
Metazoa
LRP4 of Homo sapiens
*9.B.87.2.1









Astrotactin-1, Astn1, of 1174 aas and 3 potential TMSs, with a MACPF domain.  It is a neuronal adhesion molecule that is required for glial-guided migration of young postmitotic neuroblasts in cortical regions of the developing brain, including the cerebrum, hippocampus, cerebellum and olfactory bulb. It functions in proliferation and migration of Schwann cells (Yi et al. 2016).

Eukaryota
Metazoa
Astrotactin-1 of Homo sapiens
*9.B.87.3.1









The microneme organelles of Toxoplasma gondii tachyzoites release protein complexes (MICs), including one composed of the transmembrane protein MIC6 plus MIC1 and MIC4 (Sawmynaden et al. 2008). In this complex, carbohydrate recognition domains of MIC1 and MIC4 are exposed and interact with terminal sialic acid and galactose residues, respectively, of host cell glycans (Costa Mendonça-Natividade et al. 2019). MIC1 (456 aas and 1 TMS)/MIC4 (580 aas and 1 TMS)/MIC6 (349 aas and 1 TMS) form a complex together.  MIC1 and MIC4 are adhesins that are required for attachment of the parasite to the host cell prior to invasion (Brecht et al. 2001). MIC1 also ensures correct folding of MIC6 and transport of the MIC6-MIC1-MIC4 complex into the micronemes. MIC1 has a galectin-like domain (Saouros et al. 2005). MIC6 is an escort protein for the two adhesins, MIC1 and MIC4 (Reiss et al. 2001).galectin-like domain

galectin-like domain

galectin-like doma
galectin-like domaingalectin-like domain

Eukaryota
Apicomplexa
MIC1/4/6 of Toxoplasma gondii