title: Regulation of rDNA stability by sumoylation.
abstract: Repair of DNA lesions by homologous recombination relies on the copying of genetic information from an intact homologous sequence. However, many eukaryotic genomes contain repetitive sequences such as the ribosomal gene locus (rDNA), which poses a risk for illegitimate recombination. Therefore, the eukaryotic cell has evolved mechanisms to favor equal sister chromatid exchange (SCE) and suppress unequal SCE, single-strand annealing and break-induced replication. In the budding yeast Saccharomyces cerevisiae, the tight regulation of homologous recombination at the rDNA locus is dependent on the Smc5-Smc6 complex and sumoylation of Rad52, which directs DNA double-strand breaks in the rDNA to relocalize from within the nucleolus to the nucleoplasm before association with the recombination machinery. The relocalization before repair is important for maintaining rDNA stability. The focus of this review is the regulation of recombinational DNA repair at the rDNA locus by sumoylation and the Smc5-Smc6 complex in S. cerevisiae.
authors.affiliation: Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
authors.forename: Nadine
authors.initials: N
authors.lastname: Eckert-Boulet
authors.forename: Michael
authors.initials: M
authors.lastname: Lisby
mesh_terms: D018797:Cell Cycle Proteins / Q000502:physiology; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D043243:DNA Sequence, Unstable; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D051721:Rad52 DNA Repair and Recombination Protein / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004275:DNA, Ribosomal; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; C486627:SMC5 protein, S cerevisiae; C486631:SMC6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins