Inactivation of c-Yes tyrosine kinase by elevation of intracellular calcium levels

Yuhang Zhao, Hendrik Uyttendaele, James G. Krueger, Marius Sudol, Hidesaburo Hanafusa

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35 Scopus citations


We have previously shown that the c-Src tyrosine kinase is activated four- to fivefold when cultured keratinocytes differentiate following the elevation of intracellular calcium levels. In contrast to c-Src, another Src family tyrosine kinase, c-Yes, was rapidly inactivated in these same cells, despite its marked similarity in structure and enzymatic activity to c-Src. The inactivation of c-Yes was independent of the protein kinase C pathway, which is usually activated by elevation of intracellular calcium levels. The protein levels of c-Src and c-Yes were not altered, but the phosphotyrosine content of both proteins was greatly reduced. As has been demonstrated for c-Src, in vitro dephosphorylation of c-Yes by incubation with protein tyrosine phosphatases also resulted in its activation, not inactivation. In vitro reconstitution experiments showed that c-Yes can be inactivated by preincubation with a Ca2+-supplemented cell extract and that this inhibition was reversed by the addition of EGTA [ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid]. Gradient sedimentation of cell lysates showed that in cells treated with calcium and ionophore, c-Yes formed complexes with two distinct cellular proteins, whereas similar complexes were not seen in c-Src immunoprecipitates. One of these two proteins has the ability to inhibit c-Yes kinase activity in vitro. Finally, the Ca2+-dependent inactivation of c-Yes was observed in kidney tubular cells and fibroblasts, suggesting that the Ca2+-dependent regulation of c-Yes tyrosine kinase is not unique to keratinocytes. We postulate that c-Yes is inactivated through a Ca2+-dependent association with cellular proteins, which seems to override its activation resulting from tyrosine dephosphorylation.

Original languageEnglish
Pages (from-to)7507-7514
Number of pages8
JournalMolecular and Cellular Biology
Issue number12
StatePublished - Dec 1993
Externally publishedYes


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