Slx4 and Rtt107 control checkpoint signalling and DNA resection at double-strand breaks.
The DNA damage checkpoint pathway is activated in response to DNA lesions and replication stress to preserve genome integrity. However, hyper-activation of this surveillance system is detrimental to the cell, because it might prevent cell cycle re-start after repair, which may also lead to senescence. Here we show that the scaffold proteins Slx4 and Rtt107 limit checkpoint signalling at a persistent double-strand DNA break (DSB) and at uncapped telomeres. We found that Slx4 is recruited within a few kilobases of an irreparable DSB, through the interaction with Rtt107 and the multi-BRCT domain scaffold Dpb11. In the absence of Slx4 or Rtt107, Rad9 binding near the irreparable DSB is increased, leading to robust checkpoint signalling and slower nucleolytic degradation of the 5' strand. Importantly, in slx4Δ sae2Δ double mutant cells these phenotypes are exacerbated, causing a severe Rad9-dependent defect in DSB repair. Our study sheds new light on the molecular mechanism that coordinates the processing and repair of DSBs with DNA damage checkpoint signalling, preserving genome integrity.
Department of Biosciences, University of Milan, 20133, Milano, Italy.
Diego
D
Dibitetto
Department of Biosciences, University of Milan, 20133, Milano, Italy.
Matteo
M
Ferrari
Department of Biosciences, University of Milan, 20133, Milano, Italy.
Chetan C
CC
Rawal
Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S3E1, Canada Donnelly Centre, University of Toronto, Toronto, Ontario, M5S3E1, Canada.
Attila
A
Balint
Donnelly Centre, University of Toronto, Toronto, Ontario, M5S3E1, Canada Department of Computer Science, University of Toronto, Toronto, Ontario, M5S3E1, Canada.
TaeHyung
T
Kim
Donnelly Centre, University of Toronto, Toronto, Ontario, M5S3E1, Canada Department of Computer Science, University of Toronto, Toronto, Ontario, M5S3E1, Canada.
Zhaolei
Z
Zhang
Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA.
Marcus B
MB
Smolka
Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S3E1, Canada Donnelly Centre, University of Toronto, Toronto, Ontario, M5S3E1, Canada.
Grant W
GW
Brown
Department of Biosciences, University of Milan, 20133, Milano, Italy.
Federica
F
Marini
Department of Biosciences, University of Milan, 20133, Milano, Italy achille.pellicioli@unimi.it.
Achille
A
Pellicioli
D002166:Camptothecin / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D016615:Telomere / Q000235:genetics / Q000378:metabolism; D059004:Topoisomerase I Inhibitors / Q000494:pharmacology
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C501265:RTT107 protein, S cerevisiae; C107849:SAE2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D059004:Topoisomerase I Inhibitors; C069930:rad9 protein; D008741:Methyl Methanesulfonate; D004706:Endodeoxyribonucleases; D004720:Endonucleases; C411624:MUS81 protein, S cerevisiae; C069266:RAD1 protein, S cerevisiae; C507304:SLX1 protein, S cerevisiae; C505436:SLX4 protein, S cerevisiae; D045643:DNA Repair Enzymes; D002166:Camptothecin