ZFIN ID: ZDB-PUB-150207-1
Roles of mRNA-fate modulators Dhh1 and Pat1 in TNRC6-dependent gene silencing recapitulated in yeast
Makino, S., Mishima, Y., Inoue, K., Inada, T.
Date: 2015
Source: The Journal of biological chemistry   290(13): 8331-47 (Journal)
Registered Authors: Inoue, Kunio, Mishima, Yuichiro
Keywords: gene silencing, mRNA decay, miRNA mechanism, translation regulation, yeast, zebrafish
MeSH Terms:
  • Animals
  • Autoantigens/physiology*
  • Cell Cycle Proteins/metabolism
  • DEAD-box RNA Helicases/physiology*
  • Embryo, Nonmammalian/metabolism
  • Gene Expression Regulation, Fungal
  • Polyadenylation
  • Protein Biosynthesis
  • RNA Interference
  • RNA Stability
  • RNA, Fungal/genetics
  • RNA, Fungal/metabolism
  • RNA, Messenger/genetics
  • RNA, Messenger/metabolism
  • RNA-Binding Proteins/physiology*
  • Ribonucleases/metabolism
  • Saccharomyces cerevisiae/genetics*
  • Saccharomyces cerevisiae/metabolism
  • Saccharomyces cerevisiae Proteins/metabolism
  • Saccharomyces cerevisiae Proteins/physiology*
  • Transcription Factors/metabolism
  • Zebrafish/genetics
  • Zebrafish/metabolism
  • Zebrafish Proteins/physiology*
PubMed: 25657010 Full text @ J. Biol. Chem.
The CCR4-NOT complex, the major deadenylase in eukaryotes, plays crucial roles in gene expression at the levels of transcription, mRNA decay, and protein degradation. GW182/TNRC6 proteins, which are core components of the microRNA-induced silencing complex (miRISC) in animals, stimulate deadenylation and repress translation via recruitment of the CCR4-NOT complex. Here we report a heterologous experimental system that recapitulates the recruitment of CCR4-NOT complex by TNRC6 in S. cerevisiae. Using this system, we characterize conserved functions of the CCR4-NOT complex. The complex stimulates degradation of mRNA from the 5' end by Xrn1, in a manner independent of both translation and deadenylation. This degradation pathway is likely conserved in miRNA-mediated gene silencing in zebrafish. Furthermore, the mRNA-fate modulators Dhh1 and Pat1 redundantly stimulate mRNA decay, but both factors are required for poly(A) tail-independent translation repression by tethered TNRC6A. Our tethering-based reconstitution system reveals that the conserved architecture of Not1/CNOT1 provides a binding surface for TNRC6, thereby connecting miRISC to the decapping machinery as well as the translation apparatus.