A single point mutation has pleiotropic effects on pp60v-src function.
The Rous sarcoma virus mutant tsLA29 encodes a pp60v-src molecule that is temperature sensitive for both tyrosine kinase activity and its ability to locate at the cell periphery. The defect in localization appears to be due to a perturbation in events following complex dissociation, since the mutant enzyme shows a rapidly reversible association with the cytoskeleton when shifted between permissive and restrictive temperatures. Although tsLA29 pp60v-src differs from the wild type at three amino acid residues, studies with chimeric proteins show that only one of the mutations, an alanine-for-proline substitution at residue 507, accounts for all the temperature-sensitive characteristics. Moreover, a single second site mutation, at residue 427, can restore the wild phenotype. Cells infected with a chimeric virus encoding only the alanine substitution at position 507 have a conspicuously fusiform morphology, suggesting that this mutation also has subtle effects on pp60v-src function that are apparently compensated for by the other mutations in native tsLA29.
D000818:Animals; D001483:Base Sequence; D002451:Cell Compartmentation; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002645:Chickens; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D046911:Macromolecular Substances; D009154:Mutation; D015688:Oncogene Protein pp60(v-src); D011505:Protein-Tyrosine Kinases / Q000502:physiology*; D051381:Rats; D011994:Recombinant Proteins / Q000502:physiology; D012191:Retroviridae Proteins / Q000502:physiology*; D013329:Structure-Activity Relationship; D013696:Temperature
D046911:Macromolecular Substances; D011994:Recombinant Proteins; D012191:Retroviridae Proteins; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)