title: Structural domains of the avian erythroblastosis virus erbB protein required for fibroblast transformation: dissection by in-frame insertional mutagenesis.
abstract: Avian erythroblastosis virus (AEV) induces erythroblastosis and fibrosarcomas. The viral erbB protein is required for AEV-mediated oncogenesis. To explore the structural aspects of the v-erbB polypeptide necessary for its oncogenic function, we created a series of small in-frame insertions in different domains of the v-erbB oncogene. AEV genomes bearing lesions within the v-erbB kinase domain demonstrated a drastically decreased ability to transform avian fibroblasts, establishing a functional role for this structurally conserved oncogene domain. In contrast, mutations in the extracellular domain, between the transmembrane region and the kinase domain, or at the extreme C terminus of the v-erbB protein had no effect on AEV-mediated fibroblast transformation. One lesion within the v-erbB kinase domain, a 10-amino acid insertion, produced a temperature-sensitive mutant capable of fibroblast transformation at 36 degrees C but not at 41 degrees C, suggesting that small in-frame insertions have general utility for the in vitro creation of conditional mutants.
mesh_terms: D001355:Alpharetrovirus / Q000235:genetics* / Q000502:physiology; D000818:Animals; D001354:Avian Leukosis Virus / Q000235:genetics*; D002455:Cell Division; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002642:Chick Embryo; D004251:DNA Transposable Elements; D003847:Deoxyglucose / Q000378:metabolism; D005347:Fibroblasts; D005814:Genes, Viral; D009154:Mutation; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000502:physiology; D009857:Oncogenes; D010641:Phenotype; D010960:Plasminogen Activators / Q000096:biosynthesis; D013696:Temperature; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics* / Q000502:physiology
chemical_list: D004251:DNA Transposable Elements; D009856:Oncogene Proteins, Viral; D014764:Viral Proteins; D003847:Deoxyglucose; D010960:Plasminogen Activators