CD8 alpha

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.

Post-translational modifications

Palmitoylated, but association with CD8B seems to be more important for the enrichment of CdD8A in lipid rafts.

Phosphorylated in cytotoxic T-lymphocytes (CTLs) following activation.

Cellular localization

• Cell membrane
• Single-pass type I membrane protein
• Cd8a localizes to lipid rafts only when associated with its partner Cd8b.

Alternative names

• T-cell surface glycoprotein CD8 alpha chain
• T-cell surface glycoprotein Lyt-2
• Cd8a
• Lyt-2
• Lyt2

Database links

• entrezGene:12525
• swissprot:P01731

Target type

Proteins

Primary research area

Immuno-oncology

Other research areas

• Immunology & Infectious Disease

Molecular weight

0Da