Drosophila ribosomal proteins are associated with linker histone H1 and suppress gene transcription

Genes Dev. 2006 Jul 15;20(14):1959-73. doi: 10.1101/gad.390106. Epub 2006 Jun 30.

Abstract

The dynamics and function of ribosomal proteins in the cell nucleus remain enigmatic. Here we provide evidence that specific components of Drosophila melanogaster ribosomes copurify with linker histone H1. Using various experimental approaches, we demonstrate that this association of nuclear ribosomal proteins with histone H1 is specific, and that colocalization occurs on condensed chromatin in vivo. Chromatin immunoprecipitation analysis confirmed that specific ribosomal proteins are associated with chromatin in a histone H1-dependent manner. Overexpression of either histone H1 or ribosomal protein L22 in Drosophila cells resulted in global suppression of the same set of genes, while depletion of H1 and L22 caused up-regulation of tested genes, suggesting that H1 and ribosomal proteins are essential for transcriptional gene repression. Overall, this study provides evidence for a previously undefined link between ribosomal proteins and chromatin, and suggests a role for this association in transcriptional regulation in higher eukaryotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Nucleus / metabolism
  • Chromatin / metabolism
  • Chromatin Immunoprecipitation
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics*
  • Gene Expression Regulation
  • Histones / genetics
  • Histones / metabolism*
  • Molecular Sequence Data
  • RNA / genetics
  • RNA / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / metabolism*
  • Transcription, Genetic*

Substances

  • Chromatin
  • Drosophila Proteins
  • Histones
  • RNA-Binding Proteins
  • Ribosomal Proteins
  • RpL22 protein, Drosophila
  • RpL7 protein, Drosophila
  • RNA