Evidence for ORC-dependent repression of budding yeast genes induced by starvation and other stresses

FEMS Yeast Res. 2006 Aug;6(5):763-76. doi: 10.1111/j.1567-1364.2006.00077.x.

Abstract

The highly conserved origin recognition complex (ORC) is required for repressing genes in the silent mating type loci of budding yeast. Here we report that at a non-permissive temperature, the temperature-sensitive orc2-1 mutation induces the expression of more than 500 genes, the majority of which are also induced during starvation of wild-type cells. Many genes induced by starvation or by the orc2-1 mutation are also induced by inactivation of proteins required for chromatin-mediated repression of transcription. Genes induced by the orc2-1 mutation, starvation, or inactivation of repressor proteins, map near ORC-binding loci significantly more frequently compared to all genes. Genes repressed by starvation map near ORC-binding sites less frequently compared to all genes, which suggests they have been evolutionarily excluded from regions of repressive chromatin near ORC-binding sites. Deletion of sequences containing ORC-binding sites near the DAL2 and DAL4 genes in the DAL gene cluster, which are induced by either the orc2-1 mutation or by starvation, constitutively activates these genes and abolishes their activation by the orc2-1 mutation. Our findings suggest a role for ORC in the repression of a large number of budding yeast genes induced by starvation or other aspects of a deleterious environment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Binding Sites
  • DNA Damage
  • Gene Expression Regulation, Fungal
  • Multigene Family
  • Mutation
  • Origin Recognition Complex / genetics
  • Origin Recognition Complex / physiology*
  • Repressor Proteins / physiology*
  • Saccharomycetales / genetics*
  • Saccharomycetales / metabolism

Substances

  • Origin Recognition Complex
  • Repressor Proteins