CD8 Rabbit Polyclonal Antibody (0108-7)

UNIPROT #

P01731

PROTEIN NAME

CD8

SYNONYMS

CD8 antibody;CD8 antigen, alpha polypeptide (p32) antibody;CD8a antibody;CD8a antigen antibody;CD8a molecule antibody;CD8A_HUMAN antibody;Leu2 antibody;Leu2 T lymphocyte antigen antibody;MAL antibody;OKT8 T cell antigen antibody;p32 antibody;T cell antigen Leu2 antibody;T cell co receptor antibody;T-cell surface glycoprotein CD8 alpha chain antibody;T-lymphocyte differentiation antigen T8/Leu-2 antibody;T8 T cell antigen antibody

POST-TRANSLATIONAL MODIFICATION

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.

SUBCELLULAR LOCATION

Cell membrane.

FUNCTION

CD8 (cluster of differentiation 8) is a transmembrane glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). Along with the TCR, the CD8 co-receptor plays a role in T cell signaling and aiding with cytotoxic T cell-antigen interactions. Like the TCR, CD8 binds to a major histocompatibility complex (MHC) molecule, but is specific for the MHC class I protein. There are two isoforms of the protein, alpha and beta, each encoded by a different gene. In humans, both genes are located on chromosome 2 in position 2p12. The CD8 co-receptor is predominantly expressed on the surface of cytotoxic T cells, but can also be found on natural killer cells, cortical thymocytes, and dendritic cells. The CD8 molecule is a marker for cytotoxic T cell population. It is expressed in T cell lymphoblastic lymphoma and hypo-pigmented mycosis fungoides. The extracellular IgV-like domain of CD8-α interacts with the α3 portion of the Class I MHC molecule. This affinity keeps the T cell receptor of the cytotoxic T cell and the target cell bound closely together during antigen-specific activation. Cytotoxic T cells with CD8 surface protein are called CD8+ T cells. The main recognition site is a flexible loop at the α3 domain of an MHC molecule. This was discovered by doing mutational analyses. The flexible α3 domain is located between residues 223 and 229 in the genome. In addition to aiding with cytotoxic T cell antigen interactions the CD8 co-receptor also plays a role in T cell signaling. The cytoplasmic tails of the CD8 co-receptor interact with Lck (lymphocyte-specific protein tyrosine kinase). Once the T cell receptor binds its specific antigen Lck phosphorylates the cytoplasmic CD3 and ζ-chains of the TCR complex which initiates a cascade of phosphorylation eventually leading to activation of transcription factors like NFAT, NF-κB, and AP-1 which affect the expression of certain genes.