CD81 a 26-kDa nonglycosylated member of the transmembrane 4 integral membrane protein superfamily, expressed by many types of cells. For example, CD81 participates with CD19 and CD21 in the signaltransduction complex associated with the B-cell receptor on human B lymph ocytes and with the CD4 and CD8 co-receptors on human thymocytes and T lymph ocytes. In mouse fetal thymic organ culture, interactions of immature thymocytes with CD81 expressed by thymic stromal cells are required to induce development of T cells with ?? T-cell receptors. Furthermore, CD81 has been shown to play a role in the regulation of rat mastcell degranulation. Despite its important roles in the immune response and wide tissue distribution, CD81-deficient mice are born without obvious developmental abnormalities. However, these mice have abnormal immune responses, and impaired fertility. Eat2 mAb cross-reacts with the rat CD81 antigen.
TAPA-1; Tspan28; Tapa1; Tapa-1; Target of the antiproliferative antibody 1