Roles of mRNA Fate Modulators Dhh1 and Pat1 in TNRC6-dependent Gene Silencing Recapitulated in Yeast

Abstract

Background: Animal microRNAs silence their target mRNAs by promoting mRNA degradation and inhibiting translation via GW182/TNRC6. Results: TNRC6 induces silencing effects in S. cerevisiae via CCR4-NOT complex and Dhh1-Pat1 when tethered to reporter mRNAs. Conclusion: TNRC6 utilizes the conserved mRNA fate modulators for gene silencing in yeast. Significance: Yeast genetic tools are now available to study intricate actions of TNRC6.

Pervasive yet nonuniform contributions of Dcp2 and Cnot7 to maternal mRNA clearance in zebrafish

“…Consistent with this observation, previous studies reported differential contributions of Dcp2 and Cnot7 to miR‐430‐mediated degradation of some mRNAs (Makino et al . ). These results indicate that each maternal mRNA differentially depends on Cnot7‐mediated deadenylation and Dcp2‐mediated decapping for degradation.…”

“…To analyze the contribution of Dcp2-mediated decapping to maternal mRNA clearance, we inhibited Dcp2 function in zebrafish embryos by over-expressing a dominant-negative form of zebrafish Dcp2 that contained mutations in its catalytic residues (van Dijk et al 2002;Makino et al 2015) (Fig. 1A, called Dcp2dominant negative (Dcp2-DN) hereafter).…”

“…Template plasmids containing Myc‐EGFP, Myc‐Cnot7‐DN and Myc‐Dcp2‐DN were described previously (Makino et al . ; Mishima & Tomari ). Briefly, Dcp2‐DN contains two mutations in its catalytic residues (Glu 147 to Ala and Glu 148 to Ala).…”

The Functions of MicroRNAs: mRNA Decay and Translational Repression

“…They showed that 4E-T promotes miRNA-mediated mRNA decay through the eIF4E-binding domain, suggesting that 4E-T bridges the 3 0 -terminal mRNA decay complex to the 5 0 m 7 G-cap via binding to eIF4E [55]. Given that RISC can induce decapping and subsequent decay of target mRNAs with the internalized poly(A) tail or target mRNAs lacking poly(A) tail [53,54], decapping is not merely a consequence of miRNA-mediated deadenylation but it can be induced in a deadenylationindependent manner. However, deadenylation normally precedes mRNA decay in mammalian Figure 1.…”

“…For more details on the structural bases for the interactions between GW182 and its interactors, see Jonas and Izaurralde [143]. decay by recruiting decapping factors onto the target mRNAs [53][54][55]. In mammalian cells, the catalytic subunit of decapping complex (DCP2), and decapping activators DCP1, RCK/p54/ DDX6 (also known as Dhh1 in yeast, Me31B in Drosophila melanogaster, and Xp54 in Xenopus) and EDC4 (also known as Ge-1 or Hedls) coimmunoprecipitated with Ago proteins [56][57][58][59].…”