Nucleosomes influence multiple steps during replication initiation

• DOI: 10.7554/elife.22512
• Publication Date: 2017-03-21T15:51:09Z
• Authors: Ishara F Azmi; Shinya Watanabe; Michael F Maloney; Sukhyun Kang; Jason A Belsky; David M MacAlpine; Craig L Peterson; Stephen P Bell
• Keywords: Origin recognition complex; Pre-replication complex; Minichromosome maintenance

Eukaryotic replication origin licensing, activation and timing are influenced by chromatin but a mechanistic understanding is lacking. Using reconstituted nucleosomal DNA assays, we assessed the impact of nucleosomes on initiation. To generate distinct landscapes, different chromatin-remodeling enzymes (CREs) were used to remodel origin-DNA templates. Nucleosomal organization two steps initiation: licensing helicase activation. Origin assays showed that local nucleosome positioning enhanced specificity modulated loading influencing ORC binding. Interestingly, SWI/SNF- RSC-remodeled permissive for reduced Specific CREs rescued these templates if added prior activation, indicating state must be established during allow efficient Our studies show directly modulate through mechanisms provide insights into regulation initiation chromatin.