RNA polymerase III transcription is repressed in response to the tumour suppressor ARF

Nucleic Acids Res. 2007;35(9):3046-52. doi: 10.1093/nar/gkm208. Epub 2007 Apr 16.

Abstract

The tumour suppressor protein ARF provides a defence mechanism against hyperproliferative stresses that can result from the aberrant activation of oncogenes. Accordingly, ARF is silenced or deleted in many human cancers. Activation of ARF can arrest growth and cell cycle progression, or trigger apoptosis. A principle mediator of these effects is p53, which ARF stabilizes by binding and inhibiting MDM2. However, ARF has additional targets and remains able to block growth in the absence of p53, albeit less efficiently. For example, ARF can suppress rRNA production in a p53-independent manner. We have found that the synthesis of tRNA by RNA polymerase III is also inhibited in response to ARF. However, in contrast to its effects on rRNA synthesis, ARF is unable to inhibit tRNA gene transcription when p53 is ablated. These results add to the growing list of cellular changes that can be triggered by ARF induction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • E2F1 Transcription Factor / metabolism
  • Humans
  • RNA Polymerase III / antagonists & inhibitors*
  • Repressor Proteins / metabolism*
  • Transcription, Genetic
  • Tumor Suppressor Protein p14ARF / metabolism*
  • Tumor Suppressor Protein p53 / physiology

Substances

  • E2F1 Transcription Factor
  • E2F1 protein, human
  • Repressor Proteins
  • Tumor Suppressor Protein p14ARF
  • Tumor Suppressor Protein p53
  • RNA Polymerase III