Characterization of sites for tyrosine phosphorylation in the transforming protein of Rous sarcoma virus (pp60v-src) and its normal cellular homologue (pp60c-src).

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作者：

Smart，J.，E.，Oppermann，H.，Czernilofsky，A.，P.，Purchio，A.，F.，Erikson，R.，L.，Bishop，J.，M.

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摘要：

The transforming protein of Rous sarcoma virus (pp60v-src) and its normal cellular homologue (pp60c-src) appear to be protein kinases that phosphorylate tyrosine in a variety of protein substrates. In addition, (pp60v-src) and (pp60c-src) are themselves phosphorylated on serine and tyrosine. It is likely that these phosphorylations serve to regulate the function(s) of (pp60v-src) and (pp60c-src). We have therefore characterized the sites of tyrosine phosphorylation in the two proteins. Tyrosine phosphorylation of (pp60v-src) in infected cells occurs mainly (if not entirely) at residue 419 in the deduced amino acid sequence of the protein. Surrounding this residue is the sequence Leu-Ile-Glu-Asp-Asn-Glu-Tyr(P)-Thr-Ala-Arg. This peptide is distinguished by the fact that three out of the four amino acids that precede the phosphorylated tyrosine are acidic in nature. These results define what may prove to be a widely used site for tyrosine phosphorylation in the regulation of cellular function. The same site was phosphorylated when partially purified (pp60v-src) was used in a phosphotransfer reaction in vitro. The results with (pp60c-src) were more complex. The site of tyrosine phosphorylation in vitro appeared to be the same as that found in (pp60v-src). By contrast, phosphorylation of (pp60c-src) in vivo apparently occurred at a different, and currently unidentified, tyrosine residue. It is therefore possible that (pp60v-src) and (pp60c-src) respond differently to regulatory influences in the intact cell.

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关键词：

Biochemistry Oncogene Tumor Virus Protein Kinase Phosphotyrosine Src Gene

DOI：

10.1073/pnas.78.10.6013

被引量：

552

年份：

1981