title: Identification of a transforming activity suppressing sequence in the c-raf oncogene.
abstract: Our previous study revealed that the rat c-raf was activated by a rearrangement leading to replacement of the amino-terminal half of the product. Therefore, we suggested that some sequences present in the amino-terminal half might prevent c-raf from becoming an active oncogene. To examine this possibility, we constructed a series of deletion mutants of c-raf cDNA by the random linker insertion method. By transfection of NIH3T3 cells with these mutants, a region whose deletion resulted in activation of c-raf was identified. This region is located at amino acid residues 245 to 261, immediate upstream of the kinase domain of the c-raf product and is rich in serine and threonine residues. This region includes a sequence of six amino acids, RSTSTP, which is conserved in the products of normal raf gene families of various species. This sequence is the best candidate for suppressing transforming activity of c-raf.
authors.affiliation: Carcinogenesis Division, National Cancer Center Research Institute, Tokyo, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Ishikawa
authors.forename: R
authors.initials: R
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Ochiai
authors.forename: F
authors.initials: F
authors.lastname: Takaku
authors.forename: T
authors.initials: T
authors.lastname: Sugimura
authors.forename: M
authors.initials: M
authors.lastname: Nagao
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002471:Cell Transformation, Neoplastic; D004247:DNA / Q000378:metabolism; D015870:Gene Expression; D016153:Genes, Suppressor; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics*; D019908:Proto-Oncogene Proteins c-raf; D011519:Proto-Oncogenes; D051381:Rats; D017384:Sequence Deletion; D014162:Transfection
chemical_list: D011518:Proto-Oncogene Proteins; D004247:DNA; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf