title: Regulation of gross chromosomal rearrangements by ubiquitin and SUMO ligases in Saccharomyces cerevisiae.
abstract: Gross chromosomal rearrangements (GCRs) are frequently observed in many cancers. Previously, we showed that inactivation of Rad5 or Rad18, ubiquitin ligases (E3) targeting for proliferating cell nuclear antigen (PCNA), increases the de novo telomere addition type of GCR (S. Smith, J. Y. Hwang, S. Banerjee, A. Majeed, A. Gupta, and K. Myung, Proc. Natl. Acad. Sci. USA 101:9039-9044, 2004). GCR suppression by Rad5 and Rad18 appears to be exerted by the RAD5-dependent error-free mode of bypass DNA repair. In contrast, Siz1 SUMO ligase and another ubiquitin ligase, Bre1, which target for PCNA and histone H2B, respectively, have GCR-supporting activities. Inactivation of homologous recombination (HR) proteins or the helicase Srs2 reduces GCR rates elevated by the rad5 or rad18 mutation. GCRs are therefore likely to be produced through the restrained recruitment of an HR pathway to stalled DNA replication forks. Since this HR pathway is compatible with Srs2, it is not a conventional form of recombinational pathway. Lastly, we demonstrate that selection of proper DNA repair pathways to stalled DNA replication forks is controlled by the Mec1-dependent checkpoint and is executed by cooperative functions of Siz1 and Srs2. We propose a mechanism for how defects in these proteins could lead to diverse outcomes (proper repair or GCR formation) through different regulation of DNA repair machinery.
authors.affiliation: Genome Instability Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Building 49, Room 4A22, Bethesda, MD 20892, USA.
authors.forename: Akira
authors.initials: A
authors.lastname: Motegi
authors.forename: Karen
authors.initials: K
authors.lastname: Kuntz
authors.forename: Anju
authors.initials: A
authors.lastname: Majeed
authors.forename: Stephanie
authors.initials: S
authors.lastname: Smith
authors.forename: Kyungjae
authors.initials: K
authors.lastname: Myung
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000235:genetics* / Q000378:metabolism*; D004265:DNA Helicases; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015321:Gene Rearrangement; D005800:Genes, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D008954:Models, Biological; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
chemical_list: C472168:Bre1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018809:Proliferating Cell Nuclear Antigen; C063607:RAD18 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D044767:Ubiquitin-Protein Ligases; C088937:MEC1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; C513623:TEL1 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C076225:RAD5 protein, S cerevisiae; D004265:DNA Helicases; C436837:Siz1 protein, S cerevisiae