title: Phosphorylations of the subcellular matrix in cells transformed by Rous' sarcoma virus.
abstract: The transforming protein of Rous' sarcoma virus (RSV) is a phosphoprotein of Mr 60 000 (pp60src) which displays protein kinase activity specific for tyrosine residues; pp60src is associated with the plasma membrane and is recovered in the detergent-insoluble material which represents the subcellular matrix of the cell. After phosphorylation of this material of RSV-transformed cells with [gamma-32P]ATP, five phosphoproteins have been detected which are not seen in normal cells. These proteins (Mr = 135 000, 125 000, 75 000, 70 000, 60 000) contain phosphotyrosine. Their phosphorylation is strongly inhibited by anti-pp60src antibodies. In cells transformed by a temperature-sensitive mutant of RSV, these phosphoproteins, present at the permissive temperature, are no longer detected at the non-permissive temperature. It is concluded that these phosphorylations are mediated by pp60src protein kinase activity. This supports a possible role of the phosphorylation of cytoskeletal proteins in the transformation process.
mesh_terms: D001358:Avian Sarcoma Viruses; D002472:Cell Transformation, Viral; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification; D012995:Solubility; D013347:Subcellular Fractions / Q000378:metabolism; D014764:Viral Proteins / Q000494:pharmacology*
chemical_list: D010750:Phosphoproteins; D014764:Viral Proteins; D011494:Protein Kinases