title: Ctp1 and the MRN-complex are required for endonucleolytic Rec12 removal with release of a single class of oligonucleotides in fission yeast.
abstract: DNA double-strand breaks (DSBs) are formed during meiosis by the action of the topoisomerase-like Spo11/Rec12 protein, which remains covalently bound to the 5' ends of the broken DNA. Spo11/Rec12 removal is required for resection and initiation of strand invasion for DSB repair. It was previously shown that budding yeast Spo11, the homolog of fission yeast Rec12, is removed from DNA by endonucleolytic cleavage. The release of two Spo11 bound oligonucleotide classes, heterogeneous in length, led to the conjecture of asymmetric cleavage. In fission yeast, we found only one class of oligonucleotides bound to Rec12 ranging in length from 17 to 27 nucleotides. Ctp1, Rad50, and the nuclease activity of Rad32, the fission yeast homolog of Mre11, are required for endonucleolytic Rec12 removal. Further, we detected no Rec12 removal in a rad50S mutant. However, strains with additional loss of components localizing to the linear elements, Hop1 or Mek1, showed some Rec12 removal, a restoration depending on Ctp1 and Rad32 nuclease activity. But, deletion of hop1 or mek1 did not suppress the phenotypes of ctp1Delta and the nuclease dead mutant (rad32-D65N). We discuss what consequences for subsequent repair a single class of Rec12-oligonucleotides may have during meiotic recombination in fission yeast in comparison to two classes of Spo11-oligonucleotides in budding yeast. Furthermore, we hypothesize on the participation of Hop1 and Mek1 in Rec12 removal.
authors.affiliation: Institute of Cell Biology, University of Bern, Switzerland.
authors.forename: Maja
authors.initials: M
authors.lastname: Rothenberg
authors.forename: Jürg
authors.initials: J
authors.lastname: Kohli
authors.forename: Katja
authors.initials: K
authors.lastname: Ludin
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D019295:Computational Biology / Q000379:methods*; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004706:Endodeoxyribonucleases / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000235:genetics / Q000378:metabolism; D008540:Meiosis; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D011995:Recombination, Genetic; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D013172:Spores, Fungal; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D048369:MAP Kinase Kinase 1; D009841:Oligonucleotides; D029702:Schizosaccharomyces pombe Proteins; C525888:Ctp1 protein, S pombe; C478035:Nbs1 protein, S pombe; C480032:Rad50 protein, S pombe; C456270:rec12 protein, S pombe; D000099257:Meiotic Recombination Protein SPO11; C119549:Mek1 protein, S pombe