title: RPA Mediates Recruitment of MRX to Forks and Double-Strand Breaks to Hold Sister Chromatids Together.
abstract: The Mre11-Rad50-Xrs2 (MRX) complex is related to SMC complexes that form rings capable of holding two distinct DNA strands together. MRX functions at stalled replication forks and double-strand breaks (DSBs). A mutation in the N-terminal OB fold of the 70 kDa subunit of yeast replication protein A, rfa1-t11, abrogates MRX recruitment to both types of DNA damage. The rfa1 mutation is functionally epistatic with loss of any of the MRX subunits for survival of replication fork stress or DSB recovery, although it does not compromise end-resection. High-resolution imaging shows that either the rfa1-t11 or the rad50Δ mutation lets stalled replication forks collapse and allows the separation not only of opposing ends but of sister chromatids at breaks. Given that cohesin loss does not provoke visible sister separation as long as the RPA-MRX contacts are intact, we conclude that MRX also serves as a structural linchpin holding sister chromatids together at breaks.
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland.
authors.forename: Andrew
authors.initials: A
authors.lastname: Seeber
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Hegnauer
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Hustedt
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland.
authors.forename: Ishan
authors.initials: I
authors.lastname: Deshpande
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Poli
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Eglinger
authors.affiliation: Institute of Human Genetics, CNRS UPR 1142, 34090 Montpellier, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pasero
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Heinz
authors.initials: H
authors.lastname: Gut
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Shinohara
authors.affiliation: Gene Center LMU Munich, Feodor-Lynen Strasse 25, 81377 Munich, Germany.
authors.forename: Karl-Peter
authors.initials: KP
authors.lastname: Hopfner
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Kenji
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland. Electronic address: susan.gasser@fmi.ch.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Gasser
mesh_terms: D000818:Animals; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases; D004843:Epistasis, Genetic; D005090:Exodeoxyribonucleases; D046912:Multiprotein Complexes / Q000378:metabolism*; D051716:Replication Protein A; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; C086930:RAD50 protein, S cerevisiae; C082728:RFA1 protein, S cerevisiae; D051716:Replication Protein A; D029701:Saccharomyces cerevisiae Proteins; C086929:XRS2 protein, S cerevisiae; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C094191:MRE11 protein, S cerevisiae
keywords: Mre11-Rad50-Xrs2; RPA; checkpoint; double-strand breaks; replication stress; sister chromatid cohesion