Functional antagonism between RNA polymerase II holoenzyme and global negative regulator NC2 in vivo

Proc Natl Acad Sci U S A. 1997 Apr 1;94(7):3145-50. doi: 10.1073/pnas.94.7.3145.

Abstract

Activation of eukaryotic class II gene expression involves the formation of a transcription initiation complex that includes RNA polymerase II, general transcription factors, and SRB components of the holoenzyme. Negative regulators of transcription have been described, but it is not clear whether any are general repressors of class II genes in vivo. We reasoned that defects in truly global negative regulators should compensate for deficiencies in SRB4 because SRB4 plays a positive role in holoenzyme function. Genetic experiments reveal that this is indeed the case: a defect in the yeast homologue of the human negative regulator NC2 (Dr1 x DRAP1) suppresses a mutation in SRB4. Global defects in mRNA synthesis caused by the defective yeast holoenzyme are alleviated by the NC2 suppressing mutation in vivo, indicating that yeast NC2 is a global negative regulator of class II transcription. These results imply that relief from repression at class II promoters is a general feature of gene activation in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Humans
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • RNA Polymerase II / metabolism*
  • Transcription, Genetic

Substances

  • RNA Polymerase II

Associated data

  • GENBANK/U18917
  • GENBANK/U32274