Histone H1 is a specific repressor of core histone acetylation in chromatin

Mol Cell Biol. 2000 Jan;20(2):523-9. doi: 10.1128/mcb.20.2.523-529.2000.

Abstract

Although a link between histone acetylation and transcription has been established, it is not clear how acetylases function in the nucleus of the cell and how they access their targets in a chromatin fiber containing H1 and folded into a highly condensed structure. Here we show that the histone acetyltransferase (HAT) p300/CBP-associated factor (PCAF), either alone or in a nuclear complex, can readily acetylate oligonucleosomal substrates. The linker histones, H1 and H5, specifically inhibit the acetylation of mono- and oligonucleosomes and not that of free histones or histone-DNA mixtures. We demonstrate that the inhibition is due mainly to steric hindrance of H3 by the tails of linker histones and not to condensation of the chromatin fiber. Cellular PCAF, which is complexed with accessory proteins in a multiprotein complex, can overcome the linker histone repression. We suggest that linker histones hinder access of PCAF, and perhaps other HATs, to their target acetylation sites and that perturbation of the linker histone organization in chromatin is a prerequisite for efficient acetylation of the histone tails in nucleosomes.

MeSH terms

  • Acetylation
  • Acetyltransferases / antagonists & inhibitors*
  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism
  • Animals
  • Binding, Competitive
  • Cattle
  • Cell Cycle Proteins / antagonists & inhibitors*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Chickens
  • Chromatin / chemistry
  • Chromatin / genetics
  • Chromatin / metabolism*
  • DNA / chemistry
  • DNA / genetics
  • DNA / metabolism
  • Histone Acetyltransferases
  • Histones / chemistry
  • Histones / deficiency
  • Histones / metabolism*
  • Micrococcal Nuclease / metabolism
  • Molecular Conformation
  • Nucleosomes / chemistry
  • Nucleosomes / genetics
  • Nucleosomes / metabolism
  • Protein Structure, Tertiary
  • Recombinant Proteins / antagonists & inhibitors
  • Recombinant Proteins / metabolism
  • Transcription Factors
  • p300-CBP Transcription Factors

Substances

  • Cell Cycle Proteins
  • Chromatin
  • Histones
  • Nucleosomes
  • Recombinant Proteins
  • Transcription Factors
  • DNA
  • Acetyltransferases
  • Histone Acetyltransferases
  • p300-CBP Transcription Factors
  • p300-CBP-associated factor
  • Micrococcal Nuclease