Inactivation of c-Yes tyrosine kinase by elevation of intracellular calcium levels.
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 Ca(2+)-supplemented cell extract and that this inhibition was reversed by the addition of EGTA [ethylene glycol-bis(beta-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 Ca(2+)-dependent inactivation of c-Yes was observed in kidney tubular cells and fibroblasts, suggesting that the Ca(2+)-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.
Zhao
Y
Y
Laboratory of Molecular Oncology, Rockefeller University, New York, New York 10021.
Uyttendaele
H
H
Krueger
J G
JG
Sudol
M
M
Hanafusa
H
H
D000081247:CSK Tyrosine-Protein Kinase; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002454:Cell Differentiation; D002478:Cells, Cultured; D006801:Humans; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors*; D051575:Proto-Oncogene Proteins c-yes; D014443:Tyrosine / Q000378:metabolism; D019061:src-Family Kinases
D011518:Proto-Oncogene Proteins; D000001:Calcimycin; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D051575:Proto-Oncogene Proteins c-yes; D019061:src-Family Kinases; C000631346:CSK protein, human; D011493:Protein Kinase C; D002118:Calcium