Active PHO5 chromatin encompasses variable numbers of nucleosomes at individual promoters

Nat Struct Mol Biol. 2006 Mar;13(3):256-63. doi: 10.1038/nsmb1062. Epub 2006 Feb 19.

Abstract

Transcriptional activation is often associated with chromatin remodeling. However, little is known about the dynamics of remodeling of nucleosome arrays in vivo. Upon induction of Saccharomyces cerevisiae PHO5, a novel kinetic assay of DNA methyltransferase accessibility showed that nucleosomes adjacent to the histone-free upstream activating sequence (UASp1) are disrupted earlier and at higher frequency in the cell population than are those more distal. Individually cloned molecules, each representing the chromatin state of a full promoter from a single cell, revealed multiple promoter classes with either no remodeling or variable numbers of disrupted nucleosomes. Individual promoters in the remodeled fraction were highly enriched for contiguous blocks of disrupted nucleosomes, the majority of which overlapped the UAS region. These results support a probabilistic model in which chromatin remodeling at PHO5 spreads from sites of transactivator association with DNA and attenuates with distance.

Publication types

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

MeSH terms

  • Acid Phosphatase
  • Chromatin Assembly and Disassembly
  • Gene Expression Regulation, Fungal
  • Kinetics
  • Methyltransferases / metabolism
  • Nucleosomes / genetics*
  • Nucleosomes / metabolism*
  • Promoter Regions, Genetic / genetics*
  • Regulatory Sequences, Nucleic Acid / genetics
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / genetics*

Substances

  • Nucleosomes
  • Saccharomyces cerevisiae Proteins
  • Methyltransferases
  • Acid Phosphatase
  • PHO5 protein, S cerevisiae