Tyrosine-protein kinase CSK (CSK)

Non-receptor tyrosine-protein kinase that plays a significant role in the regulation of cell growth, differentiation, migration and immune response. Phosphorylates tyrosine residues located in the C-terminal tails of Src-family kinases (SFKs) such as LCK, SRC, HCK, FYN, LYN, CSK or YES1.

Upon tail phosphorylation, Src-family members engage in intramolecular interactions involving the phosphotyrosine tail and the SH2 domain which lead to an inactive conformation. To inhibit SFKs, CSK is recruited to the plasma membrane via binding to transmembrane proteins or jack proteins located close to the plasma membrane.