Nucleosomes influence multiple steps during replication initiation
Name
Azmi-2017-Nucleosomes influence multiple steps.pdf
Size
3.66 MB
Format
Adobe PDF
Checksum (MD5)
64b156eb0440cbef9f5bf50d255666c0
Author(s)
Watanabe, Shinya
Kang, Sukhyun
Belsky, Jason A
MacAlpine, David M.
Peterson, Craig L
Azmi, Ishara F
Maloney, Michael Finnan
Bell, Stephen P
Date Issued
March 2017
Journal
eLife
Publisher
eLife Sciences Publications, Ltd.
Citation
Azmi, Ishara F et al. “Nucleosomes Influence Multiple Steps during Replication Initiation.” eLife 6 (2017): n. pag.
Version
Final published version
Abstract
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.
MIT Department
Massachusetts Institute of Technology. Department of Biology
Terms of Use
Creative Commons Attribution 4.0 International License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.7554/eLife.22512
