Accessory protein for MHC class-II antigen/T-cell receptor interaction. May regulate T-cell activation. Induces the aggregation of lipid rafts. Associates with LCK. Binds to HIV-1 gp120 and to P4HB/PDI and upon HIV-1 binding to the cell membrane, is part of P4HB/PDI- CD4-CXCR4-gp120 complex. Interacts with HIV-1 Envelope polyprotein gp160 and protein Vpu. Interacts with Human Herpes virus 7 capsid proteins. Interacts with PTK2/FAK1; this interaction requires the presence of HIV-1 gp120. Note: This description may include information from UniProtKB.
Protein type: Cell surface; Membrane protein, integral
Cellular Component: early endosome; endoplasmic reticulum lumen; endoplasmic reticulum membrane; external side of plasma membrane; integral to membrane; lipid raft; plasma membrane; T cell receptor complex
Molecular Function: coreceptor activity; enzyme binding; extracellular matrix structural constituent; glycoprotein binding; immunoglobulin binding; MHC class II protein binding; protein binding; protein homodimerization activity; protein kinase binding; receptor activity; transmembrane receptor activity; viral receptor activity; zinc ion binding
Biological Process: adaptive immune response; cell surface receptor linked signal transduction; cytokine production; defense response to Gram-negative bacterium; entry into host cell; enzyme linked receptor protein signaling pathway; immune response; induction by virus of cell-cell fusion in host; maintenance of cellular protein localization; positive regulation of calcium-mediated signaling; positive regulation of interleukin-2 biosynthetic process; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of protein kinase activity; positive regulation of T cell proliferation; regulation of defense response to virus by virus; regulation of T cell activation; response to estradiol stimulus; response to vitamin D; signal transduction; T cell costimulation; T cell differentiation; T cell receptor signaling pathway; T cell selection; transmembrane receptor protein tyrosine kinase signaling pathway; viral envelope fusion with host membrane
LTP: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.