Abstract
Nucleosome assembly involves deposition of a heterotetramer of histones H3/H4 onto DNA followed by two heterodimers of histones H2A/H2B. Cycles of nucleosome assembly and disassembly are essential to cellular events such as replication, transcription, and DNA repair. After synthesis in the cytoplasm, histones are shuttled into the nucleus where they are associated with chaperone proteins. Chaperones of histones H3/H4 include CAF-I, the Hir proteins, and Asf1. CAF-I and the Hir proteins function as replication-coupled and replication-independent deposition factors for H3/H4, respectively, whereas Asf1 may play a role in both pathways. In addition to acting as assembly factors, histone chaperones assist nucleosome dissociation from DNA and they may recruit other proteins to chromatin. The past few years have witnessed a notable accumulation of genetic, biochemical, and structural data on Asf1, which motivated this review. We discuss the sequence and structural features of Asf1 before considering its roles in nucleosome assembly/disassembly, the cellular response to DNA damage, and the regulation of gene expression. We emphasize the key role of Asf1 as a central node in a network of partners that place it at the crossroads of chromatin and DNA checkpoint pathways.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
