title: miRNA repression involves GW182-mediated recruitment of CCR4-NOT through conserved W-containing motifs.
abstract: miRNA-mediated repression in animals is dependent on the GW182 protein family. GW182 proteins are recruited to the miRNA repression complex through direct interaction with Argonaute proteins, and they function downstream to repress target mRNA. Here we demonstrate that in human and Drosophila melanogaster cells, the critical repressive features of both the N-terminal and C-terminal effector domains of GW182 proteins are Gly/Ser/Thr-Trp (G/S/TW) or Trp-Gly/Ser/Thr (WG/S/T) motifs. These motifs, which are dispersed across both domains and act in an additive manner, function by recruiting components of the CCR4-NOT deadenylation complex. A heterologous yeast polypeptide with engineered WG/S/T motifs acquired the ability to repress tethered mRNA and to interact with the CCR4-NOT complex. These results identify previously unknown effector motifs functioning as important mediators of miRNA-induced silencing in both species, and they reveal that recruitment of the CCR4-NOT complex by tryptophan-containing motifs acts downstream of GW182 to repress mRNAs, including inhibiting translation independently of deadenylation.
authors: Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors: Marina
authors: M
authors: Chekulaeva
authors: Hansruedi
authors: H
authors: Mathys
authors: Jakob T
authors: JT
authors: Zipprich
authors: Jan
authors: J
authors: Attig
authors: Marija
authors: M
authors: Colic
authors: Roy
authors: R
authors: Parker
authors: Witold
authors: W
authors: Filipowicz
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001324:Autoantigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000502:physiology*; D020868:Gene Silencing; D057809:HEK293 Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D034743:RNA-Induced Silencing Complex / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001324:Autoantigens; C528690:CNOT1 protein, human; D029721:Drosophila Proteins; C513405:Gw protein, Drosophila; D035683:MicroRNAs; D046912:Multiprotein Complexes; D016601:RNA-Binding Proteins; D034743:RNA-Induced Silencing Complex; C465663:TNRC6A protein, human; D014157:Transcription Factors