title: Temperature-sensitive mutations in the Saccharomyces cerevisiae MRT4, GRC5, SLA2 and THS1 genes result in defects in mRNA turnover.
abstract: In a screen for factors involved in mRNA turnover, four temperature-sensitive yeast strains (ts1189, ts942, ts817, and ts1100) exhibited defects in the decay of several mRNAs. Complementation of the growth and mRNA decay defects, and genetic experiments, revealed that ts1189 is mutated in the previously unknown MRT4 gene, ts942 is mutated in GRC5 (encoding the L9 ribosomal protein), ts817 contains a mutation in SLA2 (encoding a membrane protein), and ts1100 contains a mutation in THS1 (encoding the threonyl-tRNA synthetase). Three of the four mutants (mrt4, grc5, and sla2) were not defective in protein synthesis, suggesting that these strains contain mutations in factors that may play a specific role in mRNA decay. The mRNA stabilization observed in the ths1 strain, however, could be due to the significant drop in translation observed in this mutant at 37 degrees. While the three interesting mutants appear to encode novel mRNA decay factors, at least one could be linked to a previously characterized mRNA decay pathway. The growth and mRNA decay defects of ts942 (grc5) cells were suppressed by overexpression of the NMD3 gene, encoding a protein shown to participate in a two-hybrid interaction with the nonsense-mediated decay protein Upf1p.
authors.affiliation: Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
authors.forename: D
authors.initials: D
authors.lastname: Zuk
authors.forename: J P
authors.initials: JP
authors.lastname: Belk
authors.forename: A
authors.initials: A
authors.lastname: Jacobson
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D006207:Half-Life; D008969:Molecular Sequence Data; D009154:Mutation; D011132:Polyribosomes / Q000235:genetics / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D013489:Suppression, Genetic; D013696:Temperature; D013914:Threonine-tRNA Ligase / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins; C121972:MRT4 protein, S cerevisiae; C117894:NMD3 protein, S cerevisiae; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C082266:SLA2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C049650:ribosomal protein L9; D013914:Threonine-tRNA Ligase