Tyrosine phosphorylation of three cellular proteins correlates with transformation of rat 1 cells by pp60src.
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.
Bouton
A H
AH
Department of Microbiology and Cancer Center, University of Virginia Health Sciences Center, Charlottesville 22908.
Kanner
S B
SB
Vines
R R
RR
Parsons
J T
JT
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D020690:GTPase-Activating Proteins; D016391:Genes, src; D014644:Genetic Variation; D008970:Molecular Weight; D016296:Mutagenesis; D010449:Peptide Mapping; D010748:Phosphopeptides / Q000302:isolation & purification; D010750:Phosphoproteins / Q000302:isolation & purification*; D010766:Phosphorylation; D010957:Plasmids; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D051381:Rats; D014443:Tyrosine; D020703:ras GTPase-Activating Proteins
D020690:GTPase-Activating Proteins; D010748:Phosphopeptides; D010750:Phosphoproteins; D011506:Proteins; D020703:ras GTPase-Activating Proteins; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)