Upf1p, Nmd2p, and Upf3p regulate the decapping and exonucleolytic degradation of both nonsense-containing mRNAs and wild-type mRNAs.
In Saccharomyces cerevisiae, rapid degradation of nonsense-containing mRNAs requires the decapping enzyme Dcp1p, the 5'-to-3' exoribonuclease Xrn1p, and the three nonsense-mediated mRNA decay (NMD) factors, Upf1p, Nmd2p, and Upf3p. To identify specific functions for the NMD factors, we analyzed the mRNA decay phenotypes of yeast strains containing deletions of DCP1 or XRN1 and UPF1, NMD2, or UPF3. Our results indicate that Upf1p, Nmd2p, and Upf3p regulate decapping and exonucleolytic degradation of nonsense-containing mRNAs. In addition, we show that these factors also regulate the same processes in the degradation of wild-type mRNAs. The participation of the NMD factors in general mRNA degradation suggests that they may regulate an aspect of translation termination common to all transcripts.
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Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655-0122, USA.
Jacobson
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D048868:Adaptor Proteins, Signal Transducing; D000483:Alleles; D015152:Blotting, Northern; D005095:Exoribonucleases / Q000378:metabolism; D005656:Fungal Proteins / Q000502:physiology*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D009154:Mutation; D010641:Phenotype; D014176:Protein Biosynthesis; D012313:RNA / Q000378:metabolism; D012315:RNA Caps; D020365:RNA Helicases / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators / Q000502:physiology*
D048868:Adaptor Proteins, Signal Transducing; D005656:Fungal Proteins; C092470:NMD2 protein, S cerevisiae; D012315:RNA Caps; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C096360:UPF3 protein, S cerevisiae; C075577:RAT1 protein, S cerevisiae; D012313:RNA; D005095:Exoribonucleases; C068398:XRN1 protein, S cerevisiae; C074151:NAM7 protein, S cerevisiae; D020365:RNA Helicases