Petr Cejka
ETH Zurich
Publications 70
Crossovers generated during the repair of programmed double-strand breaks (DSBs) are essential for fertility to allow accurate homolog segregation during the first meiotic division. Most crossovers arise through the asymmetric cleavage of double-Holliday junction (dHJ) intermediates by the MutLγ endonuclease (Mlh1-Mlh3) and an elusive non-catalytic function of Exo1, and require the Cdc5/PLK1 kinase. Here we show in budding yeast that MutLγ forms a constitutive complex with Exo1, and in meiotic c...
#1Lepakshi Ranjha (USI: University of Lugano)H-Index: 7
#2Maryna Levikova (UZH: University of Zurich)H-Index: 7
Last.Petr Cejka (ETH Zurich)H-Index: 28
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Dna2 is an essential nuclease-helicase that acts in several distinct DNA metabolic pathways including DNA replication and recombination. To balance these functions and prevent unscheduled DNA degradation, Dna2 activities must be regulated. Here we show that Saccharomyces cerevisiae Dna2 function is controlled by sumoylation. We map the sumoylation sites to the N-terminal regulatory domain of Dna2 and show that in vitro sumoylation of recombinant Dna2 impairs its nuclease but not helicase activit...
#1Ilaria Ceppi (USI: University of Lugano)
#2Sean Michael Howard (USI: University of Lugano)H-Index: 3
Last.Petr Cejka (USI: University of Lugano)H-Index: 28
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BLM or WRN helicases function with the DNA2 helicase-nuclease to resect DNA double-strand breaks and initiate homologous recombination. Upon DNA unwinding by BLM/WRN, RPA directs the DNA2 nuclease to degrade the 59-strand, revealing the 39 overhang needed for recombination. RPA bound to ssDNA also represents a barrier, explaining the need for the motor activity of DNA2 to displace RPA prior to resection. Using ensemble and single molecule biochemistry, we show that phosphorylated CtIP dramatical...
#1Jen-Wei Huang (Columbia University)H-Index: 3
#2Angelo Taglialatela (Columbia University)H-Index: 3
Last.Alberto Ciccia (Columbia University)H-Index: 20
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Homologous recombination (HR) mediates the error-free repair of DNA double-strand breaks to maintain genomic stability. HR is carried out by a complex network of DNA repair factors. Here we identify C17orf53/MCM8IP, an OB-fold containing protein that binds ssDNA, as a novel DNA repair factor involved in HR. MCM8IP-deficient cells exhibit HR defects, especially in long-tract gene conversion, occurring downstream of RAD51 loading, consistent with a role for MCM8IP in HR-dependent DNA synthesis. Mo...
#1Kristina Kasaciunaite (Leipzig University)H-Index: 2
#2Fergus Fettes (Leipzig University)H-Index: 1
Last.Ralf Seidel (WWU: University of Münster)H-Index: 37
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1 CitationsSource
#1Roopesh Anand (USI: University of Lugano)H-Index: 6
#2Arti Jasrotia (UZH: University of Zurich)H-Index: 1
Last.Petr Cejka (ETH Zurich)H-Index: 28
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Abstract DNA end resection initiates DNA double‐strand break repair by homologous recombination. MRE11‐RAD50‐NBS1 and phosphorylated CtIP perform the first resection step via MRE11‐catalyzed endonucleolytic DNA cleavage. Human NBS1, more than its homologue Xrs2 in Saccharomyces cerevisiae , is crucial for this process, highlighting complex mechanisms that regulate the MRE11 nuclease in higher eukaryotes. Using a reconstituted system, we show here that NBS1, through its FHA and BRCT domains, func...
6 CitationsSource
#1Elda Cannavo (USI: University of Lugano)H-Index: 13
#2Giordano Reginato (ETH Zurich)H-Index: 1
Last.Petr Cejka (ETH Zurich)H-Index: 28
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To repair DNA double-strand breaks by homologous recombination, the 5′-terminated DNA strands must first be resected to produce 3′ overhangs. Mre11 from Saccharomyces cerevisiae is a 3′ → 5′ exonuclease that is responsible for 5′ end degradation in vivo. Using plasmid-length DNA substrates and purified recombinant proteins, we show that the combined exonuclease and endonuclease activities of recombinant MRX-Sae2 preferentially degrade the 5′-terminated DNA strand, which extends beyond the vicini...
#1Petr Cejka (USI: University of Lugano)H-Index: 28
#1Matthew J. Neale (University of Sussex)H-Index: 16
#2Dominic J. Johnson (University of Sussex)H-Index: 1
Last.Petr CejkaH-Index: 28
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Meiotic recombination events are initiated by DNA double-strand breaks (DSBs) created by the topoisomerase-like protein, Spo11. Similar to type-II topoisomerases, Spo11 becomes covalently linked to the 59 ends generated on each side of the DSB. Whilst Spo11-oligos - the product of nucleolytic removal by Mre11 - have been detected in a number of biological systems, the lifetime of the covalent Spo11-DSB precursor has not been systematically determined and may be subject to alternative processing ...
1 CitationsSource
#2Fergus FettesH-Index: 1
Last.Ralf SeidelH-Index: 37
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DNA double-strand break repair by homologous recombination employs long-range resection of the 59 DNA ends at the break points. In Saccharomyces cerevisiae, this process can be performed by the RecQ helicase Sgs1 and the helicase-nuclease Dna2. Though functional interplay has been shown, it remains unclear whether and how the proteins cooperate on the molecular level. Here, we resolved the dynamics of DNA unwinding by Sgs1 at the single molecule level and investigated its regulation by Dna2, the...