Heterochromatin formation in mammalian cells: interaction between histones and HP1 proteins

A L Nielsen; M Oulad-Abdelghani; J A Ortiz; E Remboutsika; P Chambon; R Losson

doi:10.1016/s1097-2765(01)00218-0

Heterochromatin formation in mammalian cells: interaction between histones and HP1 proteins

Mol Cell. 2001 Apr;7(4):729-39. doi: 10.1016/s1097-2765(01)00218-0.

Authors

A L Nielsen¹, M Oulad-Abdelghani, J A Ortiz, E Remboutsika, P Chambon, R Losson

Affiliation

¹ Department of Molecular and Structural Biology and Institute of Human Genetics, Aarhus University, C. F. Mollersalle 130, DK-8000 C, Aarhus, Denmark.

PMID: 11336697
DOI: 10.1016/s1097-2765(01)00218-0

Abstract

Members of the heterochromatin protein 1 (HP1) family are silencing nonhistone proteins. Here, we show that in P19 embryonal carcinoma (EC) nuclei, HP1 alpha, beta, and gamma form homo- and heteromers associated with nucleosomal core histones. In vitro, all three HP1s bind to tailed and tailless nucleosomes and specifically interact with the histone-fold of histone H3. Furthermore, HP1alpha interacts with the linker histone H1. HP1alpha binds to H3 and H1 through its chromodomain (CD) and hinge region, respectively. Interestingly, the Polycomb (Pc1/M33) CD also interacts with H3, and HP1alpha and Pc1/M33 binding to H3 is severely impaired by CD mutations known to abrogate HP1 and Polycomb silencing in Drosophila. These results define a novel function for the conserved CD and suggest that HP1 self-association and histone binding may play a crucial role in HP1-mediated heterochromatin assembly.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Animals
Binding Sites / physiology
Chromobox Protein Homolog 5
Chromosomal Proteins, Non-Histone / chemistry
Chromosomal Proteins, Non-Histone / genetics
Chromosomal Proteins, Non-Histone / metabolism*
Conserved Sequence
Drosophila
Embryonal Carcinoma Stem Cells
Epitopes / genetics
Heterochromatin / genetics
Heterochromatin / metabolism*
Histones / chemistry
Histones / genetics
Histones / metabolism*
In Vitro Techniques
Mammals
Mice
Molecular Sequence Data
Mutagenesis / physiology
Neoplastic Stem Cells
Nucleosomes / genetics
Nucleosomes / metabolism
Oligopeptides
Peptides / genetics
Polycomb Repressive Complex 1
Polycomb-Group Proteins
Protein Structure, Tertiary
Repressor Proteins / genetics
Repressor Proteins / metabolism

Substances

CBX5 protein, human
Cbx2 protein, mouse
Chromosomal Proteins, Non-Histone
Epitopes
Heterochromatin
Histones
Nucleosomes
Oligopeptides
Peptides
Polycomb-Group Proteins
Repressor Proteins
Chromobox Protein Homolog 5
FLAG peptide
Polycomb Repressive Complex 1