Deletions in the C-terminal coding region of the v-sis gene: dimerization is required for transformation.
The v-sis gene encodes chain B of platelet-derived growth factor. However, this gene codes for additional amino acids at both the N terminus and the C terminus of its gene product which are not present in the amino acid sequence of platelet-derived growth factor. We constructed a series of deletion mutants with deletions in the v-sis gene in order to define the C-terminal limit of the v-sis gene product which is required for transformation. Deletion mutants of the v-sis gene which encoded truncated gene products up to 57 residues shorter than the v-siswt gene product were still able to transform cells. The minimal transforming region of the v-sis gene product contained six residues fewer than were present in chain B of platelet-derived growth factor. Only 10 residues, including the sequence Cys-Lys-Cys, separated the smallest transforming gene product from the largest nontransforming gene product. These cysteine residues were also important for dimerization of the v-sis gene product, since all of the nontransforming v-sis deletions were unable to form dimers when they were analyzed under nonreducing conditions. Our results suggest that there is a strong connection between transformation and dimerization.
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D003062:Codon; D005796:Genes; D051379:Mice; D008979:Moloney murine leukemia virus / Q000235:genetics; D009154:Mutation; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D014162:Transfection
D003062:Codon; D010982:Platelet-Derived Growth Factor