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: Membrane protein, integral; Cell surface
Cellular Component: early endosome; endoplasmic reticulum membrane; external side of plasma membrane; lipid raft; plasma membrane
Molecular Function: enzyme binding; glycoprotein binding; MHC class II protein binding; protein binding; protein homodimerization activity; protein kinase binding; receptor activity; transmembrane receptor activity; zinc ion binding
Biological Process: cell surface receptor linked signal transduction; entry into host cell; enzyme linked receptor protein signaling pathway; induction by virus of cell-cell fusion in host; maintenance of cellular protein localization; positive regulation of protein kinase activity; regulation of defense response to virus by virus; regulation of T cell activation; signal transduction; T cell costimulation; T cell differentiation; T cell receptor signaling pathway; T cell selection; 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.