title: The RNA exosome affects iron response and sensitivity to oxidative stress.
abstract: RNA degradation plays important roles for maintaining temporal control and fidelity of gene expression, as well as processing of transcripts. In Saccharomyces cerevisiae the RNA exosome is a major 3'-to-5' exoribonuclease and also has an endonuclease domain of unknown function. Here we report a physiological role for the exosome in response to a stimulus. We show that inactivating the exoribonuclease active site of Rrp44 up-regulates the iron uptake regulon. This up-regulation is caused by increased levels of reactive oxygen species (ROS) in the mutant. Elevated ROS also causes hypersensitivity to H2O2, which can be reduced by the addition of iron to H2O2 stressed cells. Finally, we show that the previously characterized slow growth phenotype of rrp44-exo(-) is largely ameliorated during fermentative growth. While the molecular functions of Rrp44 and the RNA exosome have been extensively characterized, our studies characterize how this molecular function affects the physiology of the organism.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA.
authors.forename: Borislava
authors.initials: B
authors.lastname: Tsanova
authors.affiliation: Department of Microbiology and Physiological Systems, Albert Sherman Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
authors.forename: Phyllis
authors.initials: P
authors.lastname: Spatrick
authors.affiliation: Department of Microbiology and Physiological Systems, Albert Sherman Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
authors.forename: Allan
authors.initials: A
authors.lastname: Jacobson
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA.
authors.forename: Ambro
authors.initials: A
authors.lastname: van Hoof
mesh_terms: D004351:Drug Resistance / Q000235:genetics; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism; D063326:Exosome Multienzyme Ribonuclease Complex / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007501:Iron / Q000378:metabolism*; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D030781:Organisms, Genetically Modified; D018384:Oxidative Stress / Q000235:genetics*; D020871:RNA Stability / Q000187:drug effects / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D029701:Saccharomyces cerevisiae Proteins; D006861:Hydrogen Peroxide; D007501:Iron; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C542283:DIS3 protein, S cerevisiae
keywords: DIS3; RNA degradation; RRP44; yeast