Enzymatically inactive p60c-src mutant with altered ATP-binding site is fully phosphorylated in its carboxy-terminal regulatory region.

Published

Journal Article

Cellular src protein, p60c-src, is phosphorylated on tyrosine 527 in chicken embryo fibroblasts, and this phosphorylation is implicated in suppressing the protein-tyrosine kinase activity and transforming potential of p60c-src. To determine whether tyrosine 527 phosphorylation is dependent on p60c-src kinase activity, the ATP-binding site of chicken p60c-src was destroyed by substitution of lysine 295 with methionine. The resultant protein, p60c-src(M295), expressed either in chicken cells or in yeast, lacked detectable kinase activity. Nevertheless, tyrosine and serine phosphorylation of p60c-src(M295) overproduced in chicken cells were indistinguishable from that of authentic p60c-src. By contrast, p60c-src(M295) was not phosphorylated on tyrosine in yeast. These results suggest that a protein kinase present in chicken cells but not in yeast phosphorylates tyrosine 527 in trans, and are consistent with the possibility that this kinase is distinct from p60c-src.

Full Text

Duke Authors

Cited Authors

  • Jove, R; Kornbluth, S; Hanafusa, H

Published Date

  • September 1987

Published In

Volume / Issue

  • 50 / 6

Start / End Page

  • 937 - 943

PubMed ID

  • 2441875

Pubmed Central ID

  • 2441875

Electronic International Standard Serial Number (EISSN)

  • 1097-4172

International Standard Serial Number (ISSN)

  • 0092-8674

Digital Object Identifier (DOI)

  • 10.1016/0092-8674(87)90520-4

Language

  • eng