Zinc-induced tyrosine phosphorylation of hippocampal p60c-src is catalyzed by another protein tyrosine kinase.
Tyrosine phosphorylation of p60c-src induced by Zn2+ in rat hippocampal membranes is shown to inhibit Src tyrosine kinase activity. Zn2+ catalyzes the phosphorylation of p60c-src in the membranes but does not activate autophosphorylation of p60c-src immunoprecipitated with anti-Src monoclonal antibody. Moreover, the immunoprecipitated Src kinase has no Zn(2+)-induced activity in phosphorylation of exogenous substrate, enolase. Cyanogen bromide cleavage of p60c-src phosphorylated in the presence of Zn2+ yields a 4-kDa phosphopeptide corresponding to phosphorylation of a carboxy-terminal tyrosine residue of Src kinase. In conclusion, hippocampal membranes contain a Zn(2+)-stimulated protein tyrosine kinase capable of regulating the p60c-src activity.
Vener
A V
AV
INSERM U29, Paris, France.
Loeb
J
J
D000818:Animals; D002384:Catalysis; D003488:Cyanogen Bromide; D006624:Hippocampus / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D051381:Rats; D014443:Tyrosine / Q000378:metabolism*; D015032:Zinc / Q000494:pharmacology*
D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src); D015032:Zinc; D003488:Cyanogen Bromide