title: An mRNA decapping mutant deficient in P body assembly limits mRNA stabilization in response to osmotic stress.
abstract: Yeast is exposed to changing environmental conditions and must adapt its genetic program to provide a homeostatic intracellular environment. An important stress for yeast in the wild is high osmolarity. A key response to this stress is increased mRNA stability primarily by the inhibition of deadenylation. We previously demonstrated that mutations in decapping activators (edc3∆ lsm4∆C), which result in defects in P body assembly, can destabilize mRNA under unstressed conditions. We wished to examine whether mRNA would be destabilized in the edc3∆ lsm4∆C mutant as compared to the wild-type in response to osmotic stress, when P bodies are intense and numerous. Our results show that the edc3∆ lsm4∆C mutant limits the mRNA stability in response to osmotic stress, while the magnitude of stabilization was similar as compared to the wild-type. The reduced mRNA stability in the edc3∆ lsm4∆C mutant was correlated with a shorter PGK1 poly(A) tail. Similarly, the MFA2 mRNA was more rapidly deadenylated as well as significantly stabilized in the ccr4∆ deadenylation mutant in the edc3∆ lsm4∆C background. These results suggest a role for these decapping factors in stabilizing mRNA and may implicate P bodies as sites of reduced mRNA degradation.
authors.affiliation: Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Huch
authors.affiliation: Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Sweden.
authors.forename: Tracy
authors.initials: T
authors.lastname: Nissan
mesh_terms: D004722:Endoribonucleases / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D008074:Lipoproteins / Q000235:genetics*; D009154:Mutation; D009997:Osmotic Pressure; D010675:Pheromones / Q000235:genetics*; D020871:RNA Stability / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*
chemical_list: D008074:Lipoproteins; C095063:MFA2 protein, S cerevisiae; D010675:Pheromones; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C030052:mRNA decapping enzymes; D004722:Endoribonucleases