|CD316||IgSF8 (Immunoglobulin superfamily member 8), EWI-2, PGRL, CD81P3|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
Type 1 glycoprotein
|63 / 63|
|CD316 is expressed on B and T lymphocytes, NK cells, hepatocytes. There is a high expression in brain, kidney, testis, liver, placenta and expression in a broad range of tissues and minimal expression in peripheral blood leukocytes. It is not expressed on monocytes, polynuclear cells and platelets.|
|MOLECULAR FAMILY NAME: Belongs to the immunoglobulin gene family.|
CD316 is a single-pass type-1 613 aa glycoprotein. It contains a 27 aa N-terminal leader signal sequence, a 556 aa extracellular domain which contains 4 Ig-like C2 domains and 3 potential N-linked glycosylation sites, a 21 aa transmembrane domain and a very short cytoplasmic tail. The basic amino acids in the cytoplasmic domain may act as binding for ERM proteins that are a link to the actin cytoskeleton. CD316 is a member of a novel Ig-like protein subfamily known as EWI (glutamine-tryptophan-isoleucine) with the Ig gene superfamily. Other members of this family include CD101, IgSF3 and CD315 and are characterized by a CxxxEWI motif not found in other Ig proteins, extracellular domains composed exclusively of V-type Ig-like domain and short cytoplasmic domains. The distal 2 Ig-like domains have the greatest homology between members of the EWI family. A stretch of basic charged amino acids in the cytoplasmic domain may act as binding sites for ERM proteins that are linked to the actin cytoskeletal.
Alternative splicing yields 3 different isoforms. The Ig-like C2 domains 2 and 4 are required for interaction with CD81.
CD316 has 3 potential N-linked glycosylation sites.
|LIGANDS AND MOLECULE ASSOCIATED WITH CD316: No information.|
|CD316 associates with the tetraspanins CD9 and CD81 and forms stable CD319-CD9 and CD316-CD81 complexes. |
BIOCHEMICAL ACTIVITY: No information.
DISEASE RELEVANCE AND FUNCTION OF CD316 IN INTACT ANIMAL
The interaction of CD316 with CD9 and CD81 suggests it participates in the function with CD9 and CD81 including oocytes fertilization, tumor cell metastasis hepatitis C virus pathogenesis, nervous system development, cell proliferation and myogenesis but not with other tetraspanins or integrins. They may regulated proliferation and differentiation of keratinocytes. Recently CD316 in association with CD81 is involved in regulating cell motility and polarity and associates with CD82 to suppress prostate cancer cell migration and regulates epidermoid cell reaggregation and motility on laminin-5 with CD9 and CD81 as key linkers. CD316 may play a role on integrin dependent morphology and motility functions and may participate in the regulation of neurite outgrowth and maintence of the neural network in the brain.
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD316: No information.
SUBSTRATES: No information.
ENZYMES WHICH MODIFY CD316: No information.
For further information see Stipp, C. S. et al (2001) J. Biol. Chem. 276: 40545-40554.
Database accession numbers
Revised June 25, 2008