Nucleosomes influence multiple steps during replication initiation
Authors
Azmi, Ishara F.Watanabe, Shinya
Maloney, Michael F.
Kang, Sukhyun
Belsky, Jason A.
MacAlpine, David M.
Peterson, Craig L.
Bell, Stephen P.
UMass Chan Affiliations
Program in Molecular MedicineDocument Type
Journal ArticlePublication Date
2017-03-21Keywords
DNA Replicationeukaryotic
helicase
S. cerevisiae
biochemistry
chromatin remodeling enzyme
chromosomes
genes
nucleosome
origin licensing
Biochemistry, Biophysics, and Structural Biology
Cell and Developmental Biology
Genetics and Genomics
Metadata
Show full item recordAbstract
Eukaryotic replication origin licensing, activation and timing are influenced by chromatin but a mechanistic understanding is lacking. Using reconstituted nucleosomal DNA replication assays, we assessed the impact of nucleosomes on replication initiation. To generate distinct nucleosomal landscapes, different chromatin-remodeling enzymes (CREs) were used to remodel nucleosomes on origin-DNA templates. Nucleosomal organization influenced two steps of replication initiation: origin licensing and helicase activation. Origin licensing assays showed that local nucleosome positioning enhanced origin specificity and modulated helicase loading by influencing ORC DNA binding. Interestingly, SWI/SNF- and RSC-remodeled nucleosomes were permissive for origin licensing but showed reduced helicase activation. Specific CREs rescued replication of these templates if added prior to helicase activation, indicating a permissive chromatin state must be established during origin licensing to allow efficient origin activation. Our studies show nucleosomes directly modulate origin licensing and activation through distinct mechanisms and provide insights into the regulation of replication initiation by chromatin.Source
Elife. 2017 Mar 21;6. pii: e22512. doi: 10.7554/eLife.22512. Link to article on publisher's siteDOI
10.7554/eLife.22512Permanent Link to this Item
http://hdl.handle.net/20.500.14038/40311PubMed ID
28322723Related Resources
Rights
Copyright © 2017, Azmi et al.Distribution License
http://creativecommons.org/licenses/by/4.0/ae974a485f413a2113503eed53cd6c53
10.7554/eLife.22512