c-Kit Background Information The c-Kit proto-oncogene has been identified as a member of the receptor tyrosine kinase family and more specifically has been shown to be closely related to the platelet derived growth factor receptor (PDGFR). c-Kit, the normal cellular homolog of the HZ4-feline sarcoma virus transforming gene, v-Kit, encodes a transmembrane receptor. c-Kit has also been show to be identical with the product of the W locus in mice and as such is integral to the development of mast cells and hematopoiesis. The ligand for the c-Kit receptor (KL) has been identified and shown to be encoded at the murine steel (SI) locus. Two sites on c-Kit are able to bind SH2(CHK), the Tyr 568/570 diphosphorylated sequence and the monophosphorylated Tyr 721 sequence. SH2(CHK) binds to the two sites directly and only the Tyr 568/570, and not the Tyr 721, is able to bind SH2(CHK). The Tyr 568 and Tyr 570 residues are phosphorylated in vivo following ligand-stimulation.
p-c-Kit (Tyr 721)-R
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p-c-Kit (Tyr 721)-R: sc-23766-R. Western blot analysis of c-Kit phosphorylation in untreated (A), EGF treated (B) and EGF and lambda protein phosphatase treated (C) A-431 whole cell lysates.
