A nuclear degradation pathway controls the abundance of normal mRNAs in Saccharomyces cerevisiae.
We previously demonstrated an increased degradation of mRNAs in mutants of Saccharomyces cerevisiae having blocks in nuclear export. The degradation activity, designated DRN (degradation of mRNA in the nucleus), requires Cbc1p, a nuclear cap-binding protein, and Rrp6p, a nuclear exosome component. Microarray procedures were used to determine the half-lives of mRNAs from normal and mutant strains, leading to the tentative identification of hundreds of normal mRNAs that were notably stabilized when either CBC1 or RRP6 were deleted. Northern blot analysis of representative mRNAs confirmed the diminished degradation. One representative of this group, SKS1 mRNA, was also shown by a cytological procedure to be preferentially retained in the nucleus compared with typical mRNAs. We suggest that all normal mRNAs are subjected to degradation by DRN, but the degree of degradation is determined by the degree of nuclear retention. Furthermore, these mRNAs particularly susceptible to DRN were also diminished by overproduction of Cbc1p, demonstrating a regulatory role for CBC1. This conclusion was corroborated by finding an inverse relationship of the CBC1 and SKS1 mRNA levels in normal strains grown under different conditions.
Kuai
Letian
L
Department of Biochemistry and Biophysics, Box 712, University of Rochester Medical Center, Rochester, NY 14642, USA.
Das
Biswadip
B
Sherman
Fred
F
D002467:Cell Nucleus / Q000378:metabolism*; D005095:Exoribonucleases / Q000235:genetics / Q000502:physiology*; D063326:Exosome Multienzyme Ribonuclease Complex; D017353:Gene Deletion; D016681:Genome, Fungal; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D039381:RNA Cap-Binding Proteins; D020871:RNA Stability; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D015533:Transcriptional Activation
C120533:IMP3 protein, S cerevisiae; D009687:Nuclear Proteins; D039381:RNA Cap-Binding Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C101398:STO1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C104462:SKS1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C112610:RRP6 protein, S cerevisiae