Related Experiment Video
Updated: Dec 29, 2025
Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy
Published on: June 24, 2019
Meiotic gene silencing complex MTREC/NURS recruits the nuclear exosome to YTH-RNA-binding protein Mmi1
Yuichi Shichino1, Yoko Otsubo1,2,3, Masayuki Yamamoto1,4
1Laboratory of Cell Responses, National Institute for Basic Biology, Myodaiji, Okazaki, Aichi, Japan.
Abstract:
Accurate target recognition in transcript degradation is crucial for regulation of gene expression. In the fission yeast Schizosaccharomyces pombe, a number of meiotic transcripts are recognized by a YTH-family RNA-binding protein, Mmi1, and selectively degraded by the nuclear exosome during mitotic growth. Mmi1 forms nuclear foci in mitotically growing cells, and the nuclear exosome colocalizes to such foci. However, it remains elusive how Mmi1 and the nuclear exosome are connected. Here, we show that a complex called MTREC (Mtl1-Red1 core) or NURS (nuclear RNA silencing) that consists of a zinc-finger protein, Red1, and an RNA helicase, Mtl1, is required for the recruitment of the nuclear exosome to Mmi1 foci. Physical interaction between Mmi1 and the nuclear exosome depends on Red1. Furthermore, a chimeric protein involving Mmi1 and Rrp6, which is a nuclear-specific component of the exosome, suppresses the ectopic expression phenotype of meiotic transcripts in red1Δ cells and mtl1 mutant cells. These data indicate that the primary function of MTREC/NURS in meiotic transcript elimination is to link Mmi1 to the nuclear exosome physically.
Insights
A novel complex, MTREC/NURS, links the RNA-binding protein Mmi1 to the nuclear exosome for precise transcript degradation in yeast. This connection is essential for regulating gene expression by degrading meiotic transcripts during mitotic growth.
Area of Science:
- Molecular Biology
- Gene Regulation
- RNA Metabolism
Background:
- Accurate target recognition in transcript degradation is crucial for gene expression regulation.
- In fission yeast, Mmi1 (a YTH-family RNA-binding protein) targets meiotic transcripts for degradation by the nuclear exosome during mitosis.
- The precise mechanism connecting Mmi1 and the nuclear exosome remained unclear.
Purpose of the Study:
- To elucidate the mechanism by which Mmi1 interacts with the nuclear exosome for targeted transcript degradation.
- To identify the protein complex responsible for linking Mmi1 and the nuclear exosome.
Main Methods:
- Yeast genetics and molecular biology techniques were employed.
- Analysis of protein complex formation and localization.
- Functional assays involving chimeric proteins and mutant strains.
Main Results:
- The MTREC/NURS complex, comprising Red1 and Mtl1, is essential for recruiting the nuclear exosome to Mmi1 foci.
- Red1 mediates the physical interaction between Mmi1 and the nuclear exosome.
- A Mmi1-Rrp6 chimera rescues meiotic transcript mis-expression in MTREC/NURS mutants.
Conclusions:
- The MTREC/NURS complex acts as a crucial linker, physically connecting Mmi1 to the nuclear exosome.
- This interaction is vital for the selective elimination of meiotic transcripts, ensuring proper gene expression control in fission yeast.
More Related Videos
09:16Meiotic Spindle Assessment in Mouse Oocytes by siRNA-mediated Silencing
Published on: October 11, 2015
13:34Method for the Isolation and Identification of mRNAs, microRNAs and Protein Components of Ribonucleoprotein Complexes from Cell Extracts using RIP-Chip
Published on: September 29, 2012
Related Concept Videos
02:31Nuclear Export of mRNA
02:31Nuclear Export of mRNA
01:22MicroRNAs
01:22MicroRNAs
01:42Nuclear Export
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
02:27Nonsense-mediated mRNA Decay
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...