title: The de-ubiquitylating enzymes USP26 and USP37 regulate homologous recombination by counteracting RAP80.
abstract: The faithful repair of DNA double-strand breaks (DSBs) is essential to safeguard genome stability. DSBs elicit a signaling cascade involving the E3 ubiquitin ligases RNF8/RNF168 and the ubiquitin-dependent assembly of the BRCA1-Abraxas-RAP80-MERIT40 complex. The association of BRCA1 with ubiquitin conjugates through RAP80 is known to be inhibitory to DSB repair by homologous recombination (HR). However, the precise regulation of this mechanism remains poorly understood. Through genetic screens we identified USP26 and USP37 as key de-ubiquitylating enzymes (DUBs) that limit the repressive impact of RNF8/RNF168 on HR. Both DUBs are recruited to DSBs where they actively remove RNF168-induced ubiquitin conjugates. Depletion of USP26 or USP37 disrupts the execution of HR and this effect is alleviated by the simultaneous depletion of RAP80. We demonstrate that USP26 and USP37 prevent excessive spreading of RAP80-BRCA1 from DSBs. On the other hand, we also found that USP26 and USP37 promote the efficient association of BRCA1 with PALB2. This suggests that these DUBs limit the ubiquitin-dependent sequestration of BRCA1 via the BRCA1-Abraxas-RAP80-MERIT40 complex, while promoting complex formation and cooperation of BRCA1 with PALB2-BRCA2-RAD51 during HR. These findings reveal a novel ubiquitin-dependent mechanism that regulates distinct BRCA1-containing complexes for efficient repair of DSBs by HR.
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Typas
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Martijn S
authors.initials: MS
authors.lastname: Luijsterburg
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Wouter W
authors.initials: WW
authors.lastname: Wiegant
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Michaela
authors.initials: M
authors.lastname: Diakatou
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Angela
authors.initials: A
authors.lastname: Helfricht
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Thijssen
authors.affiliation: Biophysics of Cell Signaling, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: Bram
authors.initials: B
authors.lastname: van den Broek
authors.affiliation: Biophysics of Cell Signaling, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: Bram
authors.initials: B
authors.lastname: van de Broek
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Leon H
authors.initials: LH
authors.lastname: Mullenders
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands h.van.attikum@lumc.nl.
authors.forename: Haico
authors.initials: H
authors.lastname: van Attikum
mesh_terms: D019313:BRCA1 Protein / Q000378:metabolism; D002352:Carrier Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004268:DNA-Binding Proteins; D010450:Endopeptidases / Q000378:metabolism*; D056488:Histone Chaperones; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051135:Rad51 Recombinase / Q000378:metabolism; D059767:Recombinational DNA Repair; D000071857:Tumor Suppressor p53-Binding Protein 1; D025801:Ubiquitin / Q000037:antagonists & inhibitors; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D019313:BRCA1 Protein; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D056488:Histone Chaperones; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1; C466234:UIMC1 protein, human; C501866:USP26 protein, human; D025801:Ubiquitin; C535210:RNF168 protein, human; D044767:Ubiquitin-Protein Ligases; D051135:Rad51 Recombinase; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C559980:USP37 protein, human