Communicated by: Hiroshi Handa
Artificial recruitment of certain Mediator components affects requirement of basal transcription factor IIE
Article first published online: 8 JAN 2003
Genes to Cells
Volume 8, Issue 1, pages 41–50, January 2003
How to Cite
Sakurai, H. and Fukasawa, T. (2003), Artificial recruitment of certain Mediator components affects requirement of basal transcription factor IIE. Genes to Cells, 8: 41–50. doi: 10.1046/j.1365-2443.2003.00613.x
- Issue published online: 8 JAN 2003
- Article first published online: 8 JAN 2003
- Received: 20 September 2002 Accepted: 25 October 2002
Background: Basal transcription factors are essential for RNA polymerase II (RNAPII)-catalysed transcription of many but not all the mRNA-encoding genes in vivo as well as in vitro. For example, copper-inducible transcription of the copper metallothionein gene CUP1 occurs independently of basal factor TFIIE in budding yeast. To gain insight into the mechanism by which the requirement for TFIIE is bypassed, we artificially recruited certain constituents of Mediator, a large protein complex transmitting signals from various activators to the RNAPII machinery, to the CUP1 promoter by protein fusions with Ace1, the copper-inducible activator.
Results: Fusions with Med2 or Pgd1 activated CUP1 independently of TFIIE. Surprisingly, fusions with neither Srb5 nor Med9 circumvented TFIIE requirement for the CUP1 activation. Components of TFIID were similarly recruited to the CUP1 promoter without activation. By using a chromatin immunoprecipitation technique, we found that TFIIE is necessary for stable binding of TFIIH and RNAPII to the ADH1 promoter, whose activation requires TFIIE. However, binding of TFIIH and RNAPII to CUP1 upon its activation did not require TFIIE.
Conclusions: Our results strongly suggest that the TFIIE requirement of a gene is determined by a target(s) in Mediator through which the signal of the cognate activator is transmitted.