Transformation by Jun: requirement for leucine zipper, basic region and transactivation domain and enhancement by Fos.
Mutants in the leucine zipper and basic regions of mouse c-jun were tested for transformation in chicken embryo fibroblast cultures. Reduction or elimination of the ability of Jun to dimerize or to bind to DNA severely decreased transformation. A chicken v-jun gene from which the major transactivation domain was deleted also failed to transform. We conclude that an intact leucine zipper, basic region and transactivation domain are required for Jun-induced oncogenic transformation. Coexpression of chicken c-Fos increased formation of transformed foci by Jun proteins of moderate to low oncogenic potency but had no effect on highly transforming Jun. Chicken c-Fos could also transform chicken embryo fibroblasts on its own, albeit after prolonged culture and at a low efficiency.
Morgan
I M
IM
Department of Microbiology, University of Southern California School of Medicine, Los Angeles.
Ransone
L J
LJ
Bos
T J
TJ
Verma
I M
IM
Vogt
P K
PK
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D016762:Genes, fos; D016758:Genes, jun; D016350:Leucine Zippers / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D014176:Protein Biosynthesis; D011487:Protein Conformation; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
D004268:DNA-Binding Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D015500:Chloramphenicol O-Acetyltransferase