High-level expression of human c-jun gene causes cellular transformation of chicken embryo fibroblasts.
To analyze the transforming activity of c-jun, a Rous sarcoma virus (RSV) variant that carries human c-jun instead of v-src (JH1) was constructed. After infection onto chicken embryo fibroblasts (CEF), JH1 formed foci with a titer comparable to that of wild-type RSV, and the infected cells grew in soft agar, indicating that the human c-jun gene has transforming potential, like the v-jun gene. The expression of Fra-2, one of the recently isolated Fos-related antigens, but not Fos was detected in both JH1-infected CEF and CEF infected with the control retrovirus vector (DS3). Gel shift analysis using nuclear extracts from DS3-infected CEF revealed that the Fra-2/Jun complex contributes to the basal level of AP-1 DNA binding activity. A similar activity was detected in JH1-infected CEF, but these cells have an additional AP-1 binding activity derived from Jun homodimers that seems to play important roles in the cellular transformation.
Suzuki
T
T
Department of Tumor Virus Research, University of Tokyo.
Hashimoto
Y
Y
Okuno
H
H
Sato
H
H
Nishina
H
H
Iba
H
H
D000818:Animals; D002642:Chick Embryo; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000235:genetics*; D005347:Fibroblasts; D006801:Humans; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection; D014170:Transformation, Genetic / Q000235:genetics*
D015342:DNA Probes; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors