Investigation of the role of P130gag-fps in transformation: generation and use of a temperature-sensitive mutant P130gag-fps.

Changing Glu-1025 to Asp in Fujinami sarcoma virus P130gag-fps made the protein temperature sensitive for transformation and protein-tyrosine kinase activity. Another mutant, Phe-1073 P130gag-fps, lacking the major autophosphorylation site, has an extended latent period for transformation (G. A. Weinmaster, M. J. Zoller, M. Smith, E. Hinze, and T. Pawson, Cell 37:559-568, 1984). By introducing the Asp-1025 lesion into Phe-1073 P130gag-fps, we showed that this mutant protein is required for the maintenance of the transformed phenotype of Phe-1073 P130gag-fps-expressing cells.