CSK (5F3) Antibody

Csk (Carboxy-terminal Src kinase) is a ubiquitously expressed nonreceptor tyrosine kinase. Csk negatively regulates the Src family kinases (SFK) by phosphorylation of the SFK carboxy-terminal tyrosine. Phosphorylated carboxy-terminal tyrosine binds to the SH2 domain of SFK intramolecularly and leads to folding and inactivation of the SFK. This Csk-catalyzed SFK tyrosine phosphorylation is highly specific and exclusive. The SFK carboxy-terminal tyrosine is the only known physiological substrate of Csk. It is expressed in lungs and macrophages.