Complex chromosomal rearrangements mediated by break-induced replication involve structure-selective endonucleases.
DNA double-strand break (DSB) repair occurring in repeated DNA sequences often leads to the generation of chromosomal rearrangements. Homologous recombination normally ensures a faithful repair of DSBs through a mechanism that transfers the genetic information of an intact donor template to the broken molecule. When only one DSB end shares homology to the donor template, conventional gene conversion fails to occur and repair can be channeled to a recombination-dependent replication pathway termed break-induced replication (BIR), which is prone to produce chromosome non-reciprocal translocations (NRTs), a classical feature of numerous human cancers. Using a newly designed substrate for the analysis of DSB-induced chromosomal translocations, we show that Mus81 and Yen1 structure-selective endonucleases (SSEs) promote BIR, thus causing NRTs. We propose that Mus81 and Yen1 are recruited at the strand invasion intermediate to allow the establishment of a replication fork, which is required to complete BIR. Replication template switching during BIR, a feature of this pathway, engenders complex chromosomal rearrangements when using repeated DNA sequences dispersed over the genome. We demonstrate here that Mus81 and Yen1, together with Slx4, also promote template switching during BIR. Altogether, our study provides evidence for a role of SSEs at multiple steps during BIR, thus participating in the destabilization of the genome by generating complex chromosomal rearrangements.
Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Sevilla, Spain.
Benjamin
B
Pardo
Andrés
A
Aguilera
D002869:Chromosome Aberrations; D015825:Chromosomes, Fungal / Q000235:genetics* / Q000378:metabolism; D004260:DNA Repair; D004261:DNA Replication; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D004720:Endonucleases / Q000235:genetics* / Q000378:metabolism; D005785:Gene Conversion; D056426:Genetic Loci; D045565:Holliday Junction Resolvases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014178:Translocation, Genetic
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D004706:Endodeoxyribonucleases; D004720:Endonucleases; C411624:MUS81 protein, S cerevisiae; C505436:SLX4 protein, S cerevisiae; D045565:Holliday Junction Resolvases; C533749:Yen1 protein, S cerevisiae