Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Mol Cell Biol. 1994 Feb;14(2):1266-77.

tRNA genes as transcriptional repressor elements.

Author information

  • 1Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606.

Abstract

Eukaryotic genomes frequently contain large numbers of repetitive RNA polymerase III (pol III) promoter elements interspersed between and within RNA pol II transcription units, and in several instances a regulatory relationship between the two types of promoter has been postulated. In the budding yeast Saccharomyces cerevisiae, tRNA genes are the only known interspersed pol III promoter-containing repetitive elements, and we find that they strongly inhibit transcription from adjacent pol II promoters in vivo. This inhibition requires active transcription of the upstream tRNA gene but is independent of its orientation and appears not to involve simple steric blockage of the pol II upstream activator sites. Evidence is presented that different pol II promoters can be repressed by different tRNA genes placed upstream at varied distances in both orientations. To test whether this phenomenon functions in naturally occurring instances in which tRNA genes and pol II promoters are juxtaposed, we examined the sigma and Ty3 elements. This class of retrotransposons is always found integrated immediately upstream of different tRNA genes. Weakening tRNA gene transcription by means of a temperature-sensitive mutation in RNA pol III increases the pheromone-inducible expression of sigma and Ty3 elements up to 60-fold.

PMID:
8289806
[PubMed - indexed for MEDLINE]
PMCID:
PMC358482
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk