title: New histone supply regulates replication fork speed and PCNA unloading.
abstract: Correct duplication of DNA sequence and its organization into chromatin is central to genome function and stability. However, it remains unclear how cells coordinate DNA synthesis with provision of new histones for chromatin assembly to ensure chromosomal stability. In this paper, we show that replication fork speed is dependent on new histone supply and efficient nucleosome assembly. Inhibition of canonical histone biosynthesis impaired replication fork progression and reduced nucleosome occupancy on newly synthesized DNA. Replication forks initially remained stable without activation of conventional checkpoints, although prolonged histone deficiency generated DNA damage. PCNA accumulated on newly synthesized DNA in cells lacking new histones, possibly to maintain opportunity for CAF-1 recruitment and nucleosome assembly. Consistent with this, in vitro and in vivo analysis showed that PCNA unloading is delayed in the absence of nucleosome assembly. We propose that coupling of fork speed and PCNA unloading to nucleosome assembly provides a simple mechanism to adjust DNA replication and maintain chromatin integrity during transient histone shortage.
authors.affiliation: Biotech Research and Innovation Centre, 2 Centre for Epigenetics, and 3 The Bioinformatics Centre, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Mejlvang
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Feng
authors.forename: Constance
authors.initials: C
authors.lastname: Alabert
authors.forename: Kai J
authors.initials: KJ
authors.lastname: Neelsen
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Jasencakova
authors.forename: Xiaobei
authors.initials: X
authors.lastname: Zhao
authors.forename: Michael
authors.initials: M
authors.lastname: Lees
authors.forename: Albin
authors.initials: A
authors.lastname: Sandelin
authors.forename: Philippe
authors.initials: P
authors.lastname: Pasero
authors.forename: Massimo
authors.initials: M
authors.lastname: Lopes
authors.forename: Anja
authors.initials: A
authors.lastname: Groth
mesh_terms: D045744:Cell Line, Tumor; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D056504:Chromatin Assembly Factor-1 / Q000235:genetics / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D004249:DNA Damage / Q000235:genetics; D004261:DNA Replication; D006367:HeLa Cells; D006657:Histones / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors
chemical_list: C489780:CNOT8 protein, human; D002843:Chromatin; D056504:Chromatin Assembly Factor-1; D006657:Histones; D009707:Nucleosomes; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D014157:Transcription Factors