Author:
Ni Jian-Quan,Liu Lu-Ping,Hess Daniel,Rietdorf Jens,Sun Fang-Lin
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.
Publisher
Cold Spring Harbor Laboratory
Subject
Developmental Biology,Genetics
Reference79 articles.
1. Abmayr S.M. Carrozza M.J. Workman J.L. (2003) in Current protocols in pharmacology, Preparation of nuclear and cytoplasmic extracts from mammalian cells. ed Enna S.J. (John WIley & Sons, NY), Unit 12.3.
2. Does protein synthesis occur within the nucleus? Unambiguous evidence is still needed.;Allen;Trends Biol. Sci.,1978
3. Nonsense-mediated mRNA decay: terminating erroneous gene expression
4. Histone H1 Is Dispensable for Methylation-Associated Gene Silencing in
Ascobolus immersus
and Essential for Long Life Span
5. Exp5 exports eEF1A via tRNA from nuclei and synergizes with other transport pathways to confine translation to the cytoplasm