Accessibility of the c-Src SH2-domain for binding is increased during mitosis.
The Src homology 2 (SH2) region is a noncatalytic domain of Src-family tyrosine kinases and other proteins which participants in inter- and intramolecular interactions of tyrosine-phosphorylated proteins. A synthetic peptide modeled on the c-Src carboxyl terminus, which contains phosphotyrosine at position 527, binds recombinant SH2 and the SH2-domain of c-Src which lacks phosphotyrosine 527. Unphosphorylated peptide does not bind detectably. Thus, the phosphorylated peptide is a specific probe for investigating SH2 accessibility. Since Src and other tyrosine kinases may participate in regulating events in mitosis, we used the SH2-binding probe to test the prediction that decreased tyrosine 527 phosphorylation would lead to increased accessibility of the c-Src SH2-domain during mitosis. Probe binding to overexpressed chicken c-Src was enhanced at least 6-fold during mitosis, indicating that the c-Src SH2-domain is more accessible in this part of the cell cycle. This suggests that there may be mitosis-specific interactions of the c-Src SH2-domain with cellular proteins in vivo.
Bagrodia
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S
Department of Pathology, Cornell University, Ithaca, New York 14853.
Laudano
A P
AP
Shalloway
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D
D016475:3T3 Cells; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D002645:Chickens; D051379:Mice; D008938:Mitosis; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D011485:Protein Binding; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D010455:Peptides; D019000:Phosphotyrosine; D014443:Tyrosine; D016392:Proto-Oncogene Proteins pp60(c-src)