title: Mitochondria-mediated nuclear mutator phenotype in Saccharomyces cerevisiae.
abstract: Using Saccharomyces cerevisiae as a model organism, we analyzed the consequences of disrupting mitochondrial function on mutagenesis of the nuclear genome. We measured the frequency of canavanine-resistant colonies as a measure of nuclear mutator phenotype. Our data suggest that mitochondrial dysfunction leads to a nuclear mutator phenotype (i) when oxidative phosphorylation is blocked in wild-type yeast at mitochondrial complex III by antimycin A and (ii) in mutant strains lacking the entire mitochondrial genome (rho(0)) or those with deleted mitochondrial DNA (rho(-)). The nuclear mutation frequencies obtained for antimycin A-treated cells as well as for rho(-) and rho(0) cells were approximately 2- to 3-fold higher compared to untreated control and wild-type cells, respectively. Blockage of oxidative phosphorylation by antimycin A treatment led to increased intracellular levels of reactive oxygen species (ROS). In contrast, inactivation of mitochondrial activity (rho(-) and rho(0)) led to decreased intracellular levels of ROS. We also demonstrate that in rho(0) cells the REV1, REV3 and REV7 gene products, all implicated in error-prone translesion DNA synthesis (TLS), mediate mutagenesis in the nuclear genome. However, TLS was not involved in nuclear DNA mutagenesis caused by inhibition of mitochondrial function by antimycin A. Together, our data suggest that mitochondrial dysfunction is mutagenic and multiple pathways are involved in this nuclear mutator phenotype.
authors.affiliation: Sidney Kimmel Cancer Center, Johns Hopkins School of Medicine, Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Baltimore, MD 21231, USA.
authors.forename: Anne Karin
authors.initials: AK
authors.lastname: Rasmussen
authors.forename: Aditi
authors.initials: A
authors.lastname: Chatterjee
authors.forename: Lene Juel
authors.initials: LJ
authors.lastname: Rasmussen
authors.forename: Keshav K
authors.initials: KK
authors.lastname: Singh
mesh_terms: D000968:Antimycin A / Q000494:pharmacology; D002172:Canavanine / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000235:genetics*; D004249:DNA Damage; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009840:Oligomycins / Q000494:pharmacology; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010641:Phenotype; D011190:Potassium Cyanide / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D004791:Enzyme Inhibitors; D009840:Oligomycins; D017382:Reactive Oxygen Species; D014475:Uncoupling Agents; D002172:Canavanine; D000968:Antimycin A; D011190:Potassium Cyanide