title: Mutant LYS2 mRNAs retained and degraded in the nucleus of Saccharomyces cerevisiae.
abstract: We previously demonstrated that mRNAs retained in the nucleus of Saccharomyces cerevisiae are subjected to a degradation system-designated DRN (degradation of mRNA in the nucleus), that is diminished in cbc1-Delta or cbc2-Delta mutants lacking components of the cap-binding complex and in rrp6-Delta mutants lacking Rrp6p, a 3' to 5' nuclear exonuclease. Two mutants, lys2-187 and lys2-121, were uncovered by screening numerous lys2 mutants for suppression by cbc1-Delta and rrp6-Delta. Both mutants were identical and contained the two base changes, one of which formed a TGA nonsense codon. LYS2 mRNAs from the lys2-187 and related mutants were rapidly degraded, and the degradation was suppressed by cbc1-Delta and rrp6-Delta. The U1A-GFP imaging procedure was used to show that the lys2-187 mRNA was partially retained in the nucleus, explaining the susceptibility to DRN. The creation of several derivatives of lys2-187 by site-directed mutagenesis revealed that the in-frame TGA by itself was not responsible for the increased susceptibility to DRN. Thus, mRNAs susceptible to DRN can be formed by a 2-bp change. Furthermore, this "retention signal" causing susceptibility to DRN is lost by altering one of the base pairs, establishing that mRNAs susceptible and unsusceptible to DRN can be attributed to a single nucleotide in the proper context.
authors.affiliation: Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642, USA.
authors.forename: Biswadip
authors.initials: B
authors.lastname: Das
authors.forename: Satarupa
authors.initials: S
authors.lastname: Das
authors.forename: Fred
authors.initials: F
authors.lastname: Sherman
mesh_terms: D001483:Base Sequence; D002467:Cell Nucleus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism; D063326:Exosome Multienzyme Ribonuclease Complex; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010303:Paromomycin / Q000494:pharmacology; D039381:RNA Cap-Binding Proteins; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D004271:DNA, Fungal; D009687:Nuclear Proteins; D039381:RNA Cap-Binding Proteins; D012333:RNA, Messenger; C101398:STO1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D010303:Paromomycin; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C112610:RRP6 protein, S cerevisiae