CD8B
Description
The CD8B (CD8 subunit beta) is a protein-coding gene located on chromosome 2.
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. To function, CD8 forms a dimer, consisting of a pair of CD8 chains. The most common form of CD8 is composed of a CD8-α and CD8-β chain, both members of the immunoglobulin superfamily with an immunoglobulin variable (IgV)-like extracellular domain connected to the membrane by a thin stalk, and an intracellular tail.
Integral membrane glycoprotein that plays a critical role in the immune response. Functions as a coreceptor for MHC class I molecule:peptide complex in T-cells. Interacts simultaneously with the T-cell receptor (TCR) and MHC class I proteins presented by antigen presenting cells (APCs). Recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex. A palmitoylation site in the cytoplasmic tail contributes to partitioning of CD8 into the plasma membrane lipid rafts where signaling proteins are enriched. Initiates different intracellular signaling pathways by phosphorylating various substrates ultimately leading to lymphokine production, motility, adhesion and activation of cytotoxic T-lymphocytes (CTLs). Plays a critical role in thymic selection of CD8+ T-cells.
CD8B is also known as CD8B1, CD8beta, LEU2, LY3, LYT3, Ly-3, P37.
Associated Diseases
- progressive supranuclear palsy
- Okt4 epitope deficiency
- combined immunodeficiency with skin granulomas
- severe combined immunodeficiency due to IKK2 deficiency
- severe combined immunodeficiency due to CARD11 deficiency
- common variable immunodeficiency
- immunodeficiency 79
- immunodeficiency 18
- 22q11.2 deletion syndrome
- severe combined immunodeficiency due to CTPS1 deficiency
- immunodeficiency 19
- Wiskott-Aldrich syndrome
- immunodeficiency, common variable, 4
- immunodeficiency 99 with hypogammaglobulinemia and autoimmune cytopenias
- T-cell immunodeficiency, congenital alopecia, and nail dystrophy
- immunodeficiency 73c with defective neutrophil chemotaxis and hypogammaglobulinemia
- T-cell lymphopenia, infantile, with or without nail dystrophy, autosomal dominant
