CD81 Antibody – Hamster Monoclonal

The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. This encoded protein is a cell surface glycoprotein that is known to complex with integrins. This protein appears to promote muscle cell fusion and support myotube maintenance. Also it may be involved in signal transduction. This gene is localized in the tumor-suppressor gene region and thus it is a candidate gene for malignancies. [provided by RefSeq, Jul 2008]

Function: May play an important role in the regulation of lymphoma cell growth. Interacts with a 16-kDa Leu-13 protein to form a complex possibly involved in signal transduction. May act as the viral receptor for HCV.

Subunit structure: Plays a critical role in HCV attachment and/or cell entry by interacting with HCV E1/E2 glycoproteins heterodimer. Interacts directly with IGSF8. Interacts with CD53 and SCIMP. Interacts with IFITM1, IFITM2 and IFITM3. Part of a GPCR-tetraspanin complex consisting at least of GPR56, CD81, eventually CD9, and GNA11 in which CD81 is enhancing the association of GPR56 with GNA11. Ref.6 Ref.8 Ref.9 Ref.10 Ref.11 Ref.14

Subcellular location: Membrane; Multi-pass membrane protein.

Tissue specificity: Hematolymphoid, neuroectodermal and mesenchymal tumor cell lines.

Post-translational modification: Not glycosylated

Probable.

Involvement in disease: Immunodeficiency, common variable, 6 (CVID6) [MIM:613496]: A primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B cells is usually in the normal range, but can be low.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.12

Sequence similarities: Belongs to the tetraspanin (TM4SF) family.