Tyrosine phosphorylation of three cellular proteins correlates with transformation of rat 1 cells by pp60src

✍ Scribed by Amy H. Bouton; Steven B. Kanner; Richard R. Vines; J. Thomas Parsons

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 860 KB
• Volume: 4
• Category: Article
• ISSN: 0899-1987
• DOI: 10.1002/mc.2940040210

✦ Synopsis

The analysis of phosphotyrosine-containing proteins in Rat 1 cells overexpressing either the tyrosine kinase pp60c-src or genetic variants containing alterations in functional and structural domains has led to the identification of three proteins whose tyrosine phosphorylation correlated with pp60src-induced cellular transformation. The tyrosine phosphorylation of one of these proteins, p120, has been previously shown by us and others to coincide with the presence of kinase-activated, membrane-associated pp60src in chicken embryo cells. The second protein was identified as the ras-associated GTPase-activating protein (GAP). The third protein whose tyrosine phosphorylation was markedly elevated in Rat 1 cells expressing activated, membrane-bound forms of pp60src had an apparent molecular mass of 64-67 kDa. The electrophoretic mobility of this protein varied in cells expressing different pp60src variants. The tyrosine-phosphorylated form of p64-67 was present in immune complexes containing GAP, suggesting a stable interaction between these two cellular proteins.