Tyrosine-protein kinase CSK
Domain
The architecture of this protein is similar to that of Src-family kinases (SFKs) with one N-terminal SH3 domain, one SH2 domain, and a C-terminal kinase domain.
Function
Non-receptor tyrosine-protein kinase that plays an important 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) including LCK, SRC, HCK, FYN, LYN, CSK or YES1. Upon tail phosphorylation, Src-family members engage in intramolecular interactions between the phosphotyrosine tail and the SH2 domain that result in an inactive conformation. To inhibit SFKs, CSK is recruited to the plasma membrane via binding to transmembrane proteins or adapter proteins located near the plasma membrane. Suppresses signaling by various surface receptors, including T-cell receptor (TCR) and B-cell receptor (BCR) by phosphorylating and maintaining inactive several positive effectors such as FYN or LCK.
Post-translational modifications
Phosphorylated at Ser-364 by PKA, leading to increased activity. Autophosphorylated.
Sequence Similarities
Belongs to the protein kinase superfamily. Tyr protein kinase family. CSK subfamily.
Tissue Specificity
Expressed in lung and macrophages.
Cellular localization
- Cytoplasm
- Cell membrane
- Mainly cytoplasmic, also present in lipid rafts.
Alternative names
Tyrosine-protein kinase CSK, C-Src kinase, Protein-tyrosine kinase CYL, CSK