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Phosphatidylinositol 4,5‐bisphosphate stimulates phosphorylation of the adaptor protein Shc by c‐Src
Author(s) -
Sato Ken-ichi,
Yamamoto Hideki,
Otsuki Tetsuji,
Aoto Mamoru,
Tokmakov Alexander A,
Hayashi Fumio,
Fukami Yasuo
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00539-5
Subject(s) - phosphorylation , phosphotyrosine binding domain , signal transducing adaptor protein , phosphatidylinositol , phosphatidic acid , autophosphorylation , chemistry , biochemistry , proto oncogene tyrosine protein kinase src , phosphatidylinositol 4,5 bisphosphate , microbiology and biotechnology , fusion protein , biology , protein kinase a , sh2 domain , recombinant dna , phospholipid , membrane , gene
The adaptor protein Shc was prepared as glutathione S ‐transferase fusion proteins (GST–Shc) and used as in vitro substrate for c‐Src. Since phosphotyrosine‐binding domain of Shc has been shown to bind phosphatidyl‐inositol 4,5‐bisphosphate (PtdIns(4,5)P2) [Zhou et al. (1995) Nature 378, 584–592], effect of PtdIns(4,5)P2 on the phosphorylation of GST–Shc by c‐Src was examined. PtdIns(4,5)P2 stimulated the phosphorylation of GST–Shc without any effect on the c‐Src activity as judged by both its autophosphorylation and phosphorylation of exogenous substrate, Cdc2 peptide. On the other hand, phosphatidylserine, phosphatidic acid, phosphatidylinositol, and phosphatidylinositol 4‐phosphate but not phosphatidylcholine stimulated the c‐Src activity itself. K m for GST–Shc in the presence of 1 μM PtdIns(4,5)P2 was calculated to be 90 nM. The PtdIns(4,5)P2‐dependent phosphorylation of GST–Shc was inhibited by a GST–fusion protein containing the phosphotyrosine‐binding domain of Shc. These results suggest that PtdIns(4,5)P2 can act as a regulator of phosphorylation of Shc by c‐Src through its binding to Shc.