title: Copper tolerance of Saccharomyces cerevisiae nonsense-mediated mRNA decay mutants.
abstract: The eukaryotic nonsense-mediated mRNA (NMD) is a specialized pathway that leads to the recognition and rapid degradation of mRNAs with premature termination codons, and importantly some natural mRNAs as well. Natural mRNAs with atypically long 3'-untranslated regions (UTRs) are degraded by NMD in Saccharomyces cerevisiae. A number of S. cerevisiae mRNAs undergo alternative 3'-end processing producing mRNA isoforms that differ in their 3'-UTR lengths. Some of these alternatively 3'-end processed mRNA isoforms have atypically long 3'-UTRs and would be likely targets for NMD-mediated degradation. Here, we investigated the role NMD plays in the regulation of expression of CTR2, which encodes a vacuolar membrane copper transporter. CTR2 pre-mRNA undergoes alternative 3'-end processing to produce two mRNA isoforms with 300-nt and 2-kb 3'-UTRs. We show that both CTR2 mRNA isoforms are differentially regulated by NMD. The regulation of CTR2 mRNA by NMD has physiological consequences, since nmd mutants are more tolerant to toxic levels of copper relative to wild-type yeast cells and the copper tolerance of nmd mutants is dependent on the presence of CTR2.
authors.affiliation: Department of Biology, Baylor University, Waco, TX 76798-7388, USA.
authors.forename: Rafael
authors.initials: R
authors.lastname: Deliz-Aguirre
authors.forename: Audrey L
authors.initials: AL
authors.lastname: Atkin
authors.forename: Bessie W
authors.initials: BW
authors.lastname: Kebaara
mesh_terms: D027682:Cation Transport Proteins / Q000235:genetics; D003300:Copper / Q000378:metabolism / Q000494:pharmacology*; D004785:Environmental Pollutants / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D009154:Mutation; D059365:Nonsense Mediated mRNA Decay / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D020871:RNA Stability / Q000235:genetics*; D000080083:SLC31 Proteins; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics
chemical_list: D027682:Cation Transport Proteins; C497350:Ctr2 protein, S cerevisiae; D004785:Environmental Pollutants; D020033:Protein Isoforms; D000080083:SLC31 Proteins; D029701:Saccharomyces cerevisiae Proteins; D003300:Copper