2rsy

Structural highlights

Function

[CSK_RAT] 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 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 (By similarity).^{[1] [2]} [PHAG1_RAT] Negatively regulates TCR (T-cell antigen receptor)-mediated signaling in T-cells and FCER1 (high affinity immunoglobulin epsilon receptor)-mediated signaling in mast cells. Promotes CSK activation and recruitment to lipid rafts, which results in LCK inhibition. Inhibits immunological synapse formation by preventing dynamic arrangement of lipid raft proteins. May be involved in cell adhesion signaling.^{[3] [4] [5]}

See Also

• Tyrosine kinase

References

1. ↑ Okada M, Nada S, Yamanashi Y, Yamamoto T, Nakagawa H. CSK: a protein-tyrosine kinase involved in regulation of src family kinases. J Biol Chem. 1991 Dec 25;266(36):24249-52. PMID:1722201
2. ↑ Ruzzene M, James P, Brunati AM, Donella-Deana A, Pinna LA. Regulation of c-Fgr protein kinase by c-Src kinase (CSK) and by polycationic effectors. J Biol Chem. 1994 Jun 3;269(22):15885-91. PMID:7515063
3. ↑ Kawabuchi M, Satomi Y, Takao T, Shimonishi Y, Nada S, Nagai K, Tarakhovsky A, Okada M. Transmembrane phosphoprotein Cbp regulates the activities of Src-family tyrosine kinases. Nature. 2000 Apr 27;404(6781):999-1003. PMID:10801129 doi:10.1038/35010121
4. ↑ Takeuchi S, Takayama Y, Ogawa A, Tamura K, Okada M. Transmembrane phosphoprotein Cbp positively regulates the activity of the carboxyl-terminal Src kinase, Csk. J Biol Chem. 2000 Sep 22;275(38):29183-6. PMID:10918051 doi:10.1074/jbc.C000326200
5. ↑ Ohtake H, Ichikawa N, Okada M, Yamashita T. Cutting Edge: Transmembrane phosphoprotein Csk-binding protein/phosphoprotein associated with glycosphingolipid-enriched microdomains as a negative feedback regulator of mast cell signaling through the FcepsilonRI. J Immunol. 2002 Mar 1;168(5):2087-90. PMID:11859092