Activation of RNA Polymerase III Transcription in Cells Transformed by Simian Virus 40
AUTOR(ES)
Larminie, Christopher G. C.
FONTE
American Society for Microbiology
RESUMO
RNA polymerase (Pol) III transcription is abnormally active in fibroblasts that have been transformed by simian virus 40 (SV40). This report presents evidence that two separate components of the general Pol III transcription apparatus, TFIIIB and TFIIIC2, are deregulated following SV40 transformation. TFIIIC2 subunits are expressed at abnormally high levels in SV40-transformed cells, an effect which is observed at both protein and mRNA levels. In untransformed fibroblasts, TFIIIB is subject to repression through association with the retinoblastoma protein RB. The interaction between RB and TFIIIB is compromised following SV40 transformation. Furthermore, the large T antigen of SV40 is shown to relieve repression by RB. The E7 oncoprotein of human papillomavirus can also activate Pol III transcription, an effect that is dependent on its ability to bind to RB. The data provide evidence that both TFIIIB and TFIIIC2 are targets for activation by DNA tumor viruses.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=84300Documentos Relacionados
- Enhanced B2 transcription in simian virus 40-transformed cells is mediated through the formation of RNA polymerase III transcription complexes on previously inactive genes.
- Regulation of RNA polymerase III transcription in response to Simian virus 40 transformation.
- Induction of specific transcription by RNA polymerase III in transformed cells.
- Simian Virus 40 Transcription in Productively Infected and Transformed Cells
- Patterns of Simian Virus 40 Deoxyribonucleic Acid Transcription II. In Transformed Cells