Substrate specificities of tyrosine-specific protein kinases toward cytoskeletal proteins in vitro.

摘要: We have previously reported that fodrin (beta subunit), tubulin (alpha subunit) and microtubule-associated proteins (MAPs; MAP2 tau) are good substrates for the purified insulin receptor kinase (Kadowaki, T., Nishida, E., Kasuga, M., Akiyama, Takaku, F., Ishikawa, Sakai, H., Kathuria, S., Fujita-Yamaguchi, Y. (1985) Biochem. Biophys. Res. Commun. 127, 493-500 Kadowaki, Y., Akanuma, M. J. Biol. Chem. 260, 4016-4020). In this study, to investigate substrate specificities of tyrosine kinases, we examined actions epidermal growth factor (EGF) Rous sarcoma virus src on microfilament- microtubule-related proteins. Among microfilament-related examined, EGF phosphorylated beta subunit, but not alpha residues with a Km below micromolar range. The phosphorylation by was markedly inhibited F-actin. contrast, preferentially subunit residues. Fodrin microtubule best kinase. By favored as compared MAP2. peptide mapping produced very similar patterns phosphopeptides, while gave distinctly different pattern. When subunits preferred both extent. These results, together our previous indicate similar, identical, is from these kinases.