Nucleosome destabilization in the epigenetic regulation of gene expression.
Assembly, mobilization and disassembly of nucleosomes can influence the regulation of gene expression and other processes that act on eukaryotic DNA. Distinct nucleosome-assembly pathways deposit dimeric subunits behind the replication fork or at sites of active processes that mobilize pre-existing nucleosomes. Replication-coupled nucleosome assembly appears to be the default process that maintains silent chromatin, counteracted by active processes that destabilize nucleosomes. Nucleosome stability is regulated by the combined effects of nucleosome-positioning sequences, histone chaperones, ATP-dependent nucleosome remodellers, post-translational modifications and histone variants. Recent studies suggest that histone turnover helps to maintain continuous access to sequence-specific DNA-binding proteins that regulate epigenetic inheritance, providing a dynamic alternative to histone-marking models for the propagation of active chromatin.
Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, Washington 98109, USA. steveh@fhcrc.org
Steven
S
Henikoff
D000255:Adenosine Triphosphate / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D009707:Nucleosomes / Q000378:metabolism*; D011499:Protein Processing, Post-Translational
D002843:Chromatin; D009707:Nucleosomes; D000255:Adenosine Triphosphate; D004247:DNA