ZAP70

ZAP70 (Zeta-chain-associated protein kinase 70) is a protein that in humans is encoded by the ZAP70 gene. ZAP70 is a member of the Syk family of protein tyrosine kinases and plays a central role in T-cell receptor (TCR) signaling and T cell activation.

Function

ZAP70 is a cytoplasmic protein tyrosine kinase that is critical for T cell receptor-mediated signal transduction in response to antigen binding. The T cell receptor (TCR) and associated proteins recruit ZAP70 to the plasma membrane where it transduces the signal from the TCR into the cell interior. ZAP70 is activated by phosphorylation following TCR engagement, and this leads to the activation of downstream pathways that ultimately lead to the execution of T cell effector functions.

Clinical significance

Mutations in the ZAP70 gene cause selective T cell defect, a severe combined immunodeficiency disease characterized by a selective absence of CD8-positive T cells. ZAP70 deficiency results in a form of severe combined immunodeficiency (SCID), which is a group of disorders characterized by a block in T cell development.

See also

• Protein tyrosine kinase
• T cell receptor
• Severe combined immunodeficiency

External links

• ZAP70 at the US National Library of Medicine Medical Subject Headings (MeSH)