title: Replication-Coupled PCNA Unloading by the Elg1 Complex Occurs Genome-wide and Requires Okazaki Fragment Ligation.
abstract: The sliding clamp PCNA is a crucial component of the DNA replication machinery. Timely PCNA loading and unloading are central for genome integrity and must be strictly coordinated with other DNA processing steps during replication. Here, we show that the S. cerevisiae Elg1 replication factor C-like complex (Elg1-RLC) unloads PCNA genome-wide following Okazaki fragment ligation. In the absence of Elg1, PCNA is retained on chromosomes in the wake of replication forks, rather than at specific sites. Degradation of the Okazaki fragment ligase Cdc9 leads to PCNA accumulation on chromatin, similar to the accumulation caused by lack of Elg1. We demonstrate that Okazaki fragment ligation is the critical prerequisite for PCNA unloading, since Chlorella virus DNA ligase can substitute for Cdc9 in yeast and simultaneously promotes PCNA unloading. Our results suggest that Elg1-RLC acts as a general PCNA unloader and is dependent upon DNA ligation during chromosome replication.
authors.affiliation: Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK. Electronic address: t.kubota@abdn.ac.uk.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubota
authors.affiliation: Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Katou
authors.affiliation: Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Nakato
authors.affiliation: Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Shirahige
authors.affiliation: Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
authors.forename: Anne D
authors.initials: AD
authors.lastname: Donaldson
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication / Q000502:physiology*; D004271:DNA, Fungal / Q000096:biosynthesis* / Q000235:genetics; D016681:Genome, Fungal / Q000502:physiology; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism*; D051818:Replication Protein C / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C000607890:CDC9 protein, S cerevisiae; D002352:Carrier Proteins; D002843:Chromatin; D004271:DNA, Fungal; C477609:Elg1 protein, S cerevisiae; C022262:Okazaki fragments; D018809:Proliferating Cell Nuclear Antigen; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA; D051818:Replication Protein C; D011088:DNA Ligases; D000072481:DNA Ligase ATP