CD8A
Description
The CD8A (CD8 subunit alpha) is a protein-coding gene located on chromosome 2.
CD8A, the gene encoding T-cell surface glycoprotein CD8 alpha chain (Cluster of Differentiation 8a), is a key player in the immune system. This protein, found on cytotoxic T lymphocytes, facilitates cell-cell interactions by acting as a coreceptor alongside the T-cell receptor. Together, they recognize antigens presented by antigen-presenting cells (APCs) in the context of class I MHC molecules. CD8 can exist as either a homodimer (two alpha chains) or a heterodimer (one alpha and one beta chain). The alpha and beta chains share similarities to immunoglobulin light chains. This gene encodes the CD8 alpha chain, which can be found in two isoforms: a membrane-associated form and a secreted form. CD8A has been shown to interact with CD3D, HLA-A, and HLA-G.
CD8A plays a crucial role in the immune response, functioning as a coreceptor for MHC class I molecule:peptide complexes. It interacts with the T-cell receptor (TCR) and MHC class I proteins presented by antigen-presenting cells (APCs). By recruiting the Src kinase LCK to the TCR-CD3 complex, CD8A initiates intracellular signaling pathways that lead to lymphokine production, motility, adhesion, and activation of cytotoxic T-lymphocytes (CTLs). This process allows CTLs to identify and eliminate infected and tumor cells. In NK-cells, CD8A homodimers provide a survival mechanism enabling the conjugation and lysis of multiple target cells. Additionally, CD8A homodimer molecules contribute to the survival and differentiation of activated lymphocytes into memory CD8 T-cells.
CD8A is also known as CD8, CD8alpha, IMD116, Leu2, p32.
