Transformation-Specific Tyrosine Phosphorylation of a Novel Cellular Protein in Chicken Cells Expressing Oncogenic Variants of the Avian Cellular src Gene
Year: 1989
Type: article
Abstract: We used myristylated and nonmyristylated c-src-based variants and phosphotyrosine-specific antibodies to reevaluate the role of tyrosine phosphorylation in cellular transformation by pp60src. Prior methods used to detect tyrosine-phosphorylated proteins failed to discriminate predicted differences in tyrosine phosphorylation which are clearly observed with phosphotyrosine-specific antibodies and Western blotting (immunoblotting). Here we report the observation of a 120,000-Mr protein whose phosphorylation on tyrosine correlates with the induction of morphological transformation. p120 was not observed in cells overexpressing the regulated, nononcogenic pp60c-src, whereas phosphorylation of p120 was greatly enhanced in cells expressing activated, oncogenic pp60527F. Furthermore, phosphorylation of p120 was not induced by expression of the activated but nonmyristylated src variant pp602A/527F, which is transformation defective. p120 partitioned preferentially with cellular membranes, consistent with the observation that transforming src proteins are membrane associated. Although a number of additional putative substrates were identified and partially characterized with respect to intracellular localization, tyrosine phosphorylation of these proteins was not tightly linked to transformation.
Source: Molecular and Cellular Biology
Authors: A B Reynolds, D J Roesel, S B Kanner, J T Parsons
Institution: University of Virginia
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1912221395