Interactions of HP1 Bound to H3K9me3 Dinucleosome by Molecular Simulations and Biochemical Assays
| Autor: | Isao Suetake, Shuhei Watanabe, Shoji Takada, Masahiro Shimizu, Yuichi Mishima |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Chromosomal Proteins Non-Histone Protein Conformation Heterochromatin Biophysics Plasma protein binding Molecular Dynamics Simulation Methylation Histones 03 medical and health sciences Histone H3 0302 clinical medicine Protein structure Nucleosome Amino Acid Sequence Peptide sequence Nucleic Acids and Genome Biophysics Chemistry Lysine Nucleosomes Chromatin Cell biology 030104 developmental biology Chromobox Protein Homolog 5 Heterochromatin protein 1 030217 neurology & neurosurgery Protein Binding |
| Zdroj: | Biophysical Journal. 114:2336-2351 |
| ISSN: | 0006-3495 |
| Popis: | Heterochromatin protein 1 (HP1), associated with heterochromatin formation, recognizes an epigenetically repressive marker, trimethylated lysine 9 in histone H3 (H3K9me3), and generally contributes to long-term silencing. How HP1 induces heterochromatin is not fully understood. Recent experiments suggested that not one, but two nucleosomes provide a platform for this recognition. Integrating previous and new biochemical assays with computational modeling, we provide near-atomic structural models for HP1 binding to the dinucleosomes. We found that the dimeric HP1α tends to bind two H3K9me3s that are in adjacent nucleosomes, thus bridging two nucleosomes. We identified, to our knowledge, a novel DNA binding motif in the hinge region that is specific to HP1α and is essential for recognizing the H3K9me3 sites of two nucleosomes. An HP1 isoform, HP1γ, does not easily bridge two nucleosomes in extended conformations because of the absence of the above binding motif and its shorter hinge region. We propose a molecular mechanism for chromatin structural changes caused by HP1. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|