title: Mutagenesis of the v-mht/mil oncogene in avian carcinoma virus MH2.
abstract: Avian carcinoma retrovirus MH2 induces leukemia and solid tumors in chickens and transforms fibroblasts and macrophages in vitro. The genome of MH2 consists of two oncogenes, v-mht/mil and v-myc. Most of the transforming activity of MH2 is attributed to the v-myc oncogene. In contrast, the v-mht/mil oncogene alone does not induce a fully transformed phenotype of avian primary fibroblasts in vitro. It was shown previously that v-mht/mil is the avian homology of the v-raf oncogene in murine sarcoma retrovirus 3611. Because the v-raf oncogene transforms murine fibroblasts very efficiently, the present study tested the hypothesis that an extra segment in the 5' end of v-mht/mil relative to v-raf suppressed the fibroblast-transforming activity of v-mht/mil. By introducing an in-frame deletion of 195 nucleotides into the 5' end of v-mht/mil, the results demonstrate that in the presence of an inactive v-myc oncogene, the 5'-deleted v-mht/mil oncogene fails to transform chicken embryo fibroblasts. Therefore, it is likely that avian primary fibroblasts lack a cellular component that serves as a critical substrate/target for v-mht/mil-induced cellular transformation.
authors.affiliation: Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey 17033.
authors.forename: N C
authors.initials: NC
authors.lastname: Kan
mesh_terms: D000818:Animals; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002642:Chick Embryo; D004279:DNA, Viral / Q000235:genetics; D005347:Fibroblasts; D015967:Gene Expression Regulation, Viral; D016259:Genes, myc; D015151:Immunoblotting; D016296:Mutagenesis; D009857:Oncogenes; D010957:Plasmids; D012367:RNA, Viral / Q000032:analysis; D012190:Retroviridae / Q000235:genetics*; D014162:Transfection; D014760:Viral Fusion Proteins / Q000032:analysis
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral; D014760:Viral Fusion Proteins