Recombinant Mouse T-cell surface glycoprotein CD8 alpha chain (Cd8a), partial (Active)

Function

Integral membrane glycoprotein that plays an essential role in the immune response and serves multiple functions in responses against both external and internal offenses. In T-cells, functions primarily as a coreceptor for MHC class I molecule:peptide complex. The antigens presented by class I peptides are derived from cytosolic proteins while class II derived from extracellular proteins. Interacts simultaneously with the T-cell receptor (TCR) and the MHC class I proteins presented by antigen presenting cells (APCs). In turn, recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK then initiates different intracellular signaling pathways by phosphorylating various substrates ultimately leading to lymphokine production, motility, adhesion and activation of cytotoxic T-lymphocytes (CTLs). This mechanism enables CTLs to recognize and eliminate infected cells and tumor cells. In NK-cells, the presence of CD8A homodimers at the cell surface provides a survival mechanism allowing conjugation and lysis of multiple target cells. CD8A homodimer molecules also promote the survival and differentiation of activated lymphocytes into memory CD8 T-cells

Subcellular Location

Cell membrane (Single-pass type I membrane protein)

Subunit

Forms disulfide-linked heterodimers with CD8B at the cell surface. Also forms homodimers in several cell types including NK-cells or peripheral blood T-lymphocytes. Interacts with the MHC class I HLA-A/B2M dimer. Interacts with LCK in a zinc-dependent manner

• Nakauchi H. et al. Molecular cloning of Lyt-2, a membrane glycoprotein marking a subset of mouse T lymphocytes: molecular homology to its human counterpart, Leu-2/T8, and to immunoglobulin variable regions. — Proc. Natl. Acad. Sci. U.S.A. (1985)
• Zamoyska R. et al. Two Lyt-2 polypeptides arise from a single gene by alternative splicing patterns of mRNA. — Cell (1985)
• Nakauchi H. et al. Isolation and characterization of the gene for the murine T cell differentiation antigen and immunoglobulin-related molecule, Lyt-2. — Nucleic Acids Res. (1987)
• Youn H.J. et al. Nucleotide sequence analysis of the C.AKR Lyt-2a gene: structural polymorphism in alleles encoding the Lyt-2.1 T-cell surface alloantigen. — Immunogenetics (1988)
• Liaw C.W. et al. Structure, sequence, and polymorphism of the Lyt-2 T cell differentiation antigen gene. — J. Immunol. (1986)
• DiSanto J.P. et al. Phosphorylation and down-regulation of CD4 and CD8 in human CTLs and mouse L cells. — Immunogenetics (1989)
• Fung-Leung W.P. et al. CD8 is needed for development of cytotoxic T cells but not helper T cells. — Cell (1991)
• Madakamutil L.T. et al. CD8alphaalpha-mediated survival and differentiation of CD8 memory T cell precursors. — Science (2004)