title: H2B mono-ubiquitylation facilitates fork stalling and recovery during replication stress by coordinating Rad53 activation and chromatin assembly.
abstract: The influence of mono-ubiquitylation of histone H2B (H2Bub) on transcription via nucleosome reassembly has been widely documented. Recently, it has also been shown that H2Bub promotes recovery from replication stress; however, the underling molecular mechanism remains unclear. Here, we show that H2B ubiquitylation coordinates activation of the intra-S replication checkpoint and chromatin re-assembly, in order to limit fork progression and DNA damage in the presence of replication stress. In particular, we show that the absence of H2Bub affects replication dynamics (enhanced fork progression and reduced origin firing), leading to γH2A accumulation and increased hydroxyurea sensitivity. Further genetic analysis indicates a role for H2Bub in transducing Rad53 phosphorylation. Concomitantly, we found that a change in replication dynamics is not due to a change in dNTP level, but is mediated by reduced Rad53 activation and destabilization of the RecQ helicase Sgs1 at the fork. Furthermore, we demonstrate that H2Bub facilitates the dissociation of the histone chaperone Asf1 from Rad53, and nucleosome reassembly behind the fork is compromised in cells lacking H2Bub. Taken together, these results indicate that the regulation of H2B ubiquitylation is a key event in the maintenance of genome stability, through coordination of intra-S checkpoint activation, chromatin assembly and replication fork progression.
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan; Graduate Institute of Nutrition and Food Sciences, Fu-Jen Catholic University, Xinzhuang, New Taipei City, Taiwan.
authors.forename: Chia-Yeh
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Meng-Ying
authors.initials: MY
authors.lastname: Wu
authors.affiliation: Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), IFOM-IEO Campus, Milan, Italy.
authors.forename: Sophie
authors.initials: S
authors.lastname: Gay
authors.affiliation: Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
authors.forename: Lisette
authors.initials: L
authors.lastname: Marjavaara
authors.affiliation: Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), IFOM-IEO Campus, Milan, Italy.
authors.forename: Mong Sing
authors.initials: MS
authors.lastname: Lai
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Hsiao
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Shih-Hsun
authors.initials: SH
authors.lastname: Hung
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Tseng
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Duncan Edward
authors.initials: DE
authors.lastname: Wright
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan; Institut de Génétique et de Biologie Moléculaire. CNRS UMR 7104, INSERM U 596, Université Louis Pasteur de Strasbourg, Illkirch, CU de Strasbourg, France.
authors.forename: Chen-Yi
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Graduate Institute of Nutrition and Food Sciences, Fu-Jen Catholic University, Xinzhuang, New Taipei City, Taiwan.
authors.forename: Guoo-Shyng W
authors.initials: GS
authors.lastname: Hsu
authors.affiliation: Institut de Génétique et de Biologie Moléculaire. CNRS UMR 7104, INSERM U 596, Université Louis Pasteur de Strasbourg, Illkirch, CU de Strasbourg, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Devys
authors.affiliation: Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
authors.forename: Andrei
authors.initials: A
authors.lastname: Chabes
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Cheng-Fu
authors.initials: CF
authors.lastname: Kao
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D064447:Checkpoint Kinase 2 / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D004261:DNA Replication; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D006918:Hydroxyurea / Q000494:pharmacology; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009707:Nucleosomes / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D053484:RecQ Helicases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: C109731:ASF1 protein, S cerevisiae; D018797:Cell Cycle Proteins; D006657:Histones; D018832:Molecular Chaperones; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; C546605:BRE2 protein, S cerevisiae; D011495:Histone-Lysine N-Methyltransferase; C104169:DUN1 protein, S cerevisiae; D064447:Checkpoint Kinase 2; D017346:Protein Serine-Threonine Kinases; C067022:RAD53 protein, S cerevisiae; C090472:SGS1 protein, S cerevisiae; D053484:RecQ Helicases; D006918:Hydroxyurea