A CAF40-binding motif facilitates recruitment of the CCR4-NOT complex to mRNAs targeted by Drosophila Roquin

Nat Commun. 2017 Feb 6;8:14307. doi: 10.1038/ncomms14307.

Abstract

Human (Hs) Roquin1 and Roquin2 are RNA-binding proteins that promote mRNA target degradation through the recruitment of the CCR4-NOT deadenylase complex and are implicated in the prevention of autoimmunity. Roquin1 recruits CCR4-NOT via a C-terminal region that is not conserved in Roquin2 or in invertebrate Roquin. Here we show that Roquin2 and Drosophila melanogaster (Dm) Roquin also interact with the CCR4-NOT complex through their C-terminal regions. The C-terminal region of Dm Roquin contains multiple motifs that mediate CCR4-NOT binding. One motif binds to the CAF40 subunit of the CCR4-NOT complex. The crystal structure of the Dm Roquin CAF40-binding motif (CBM) bound to CAF40 reveals that the CBM adopts an α-helical conformation upon binding to a conserved surface of CAF40. Thus, despite the lack of sequence conservation, the C-terminal regions of Roquin proteins act as an effector domain that represses the expression of mRNA targets via recruitment of the CCR4-NOT complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Conserved Sequence
  • Crystallography, X-Ray
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / metabolism
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • RNA Stability / physiology*
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Ribonucleases / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Ubiquitin-Protein Ligases / chemistry
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*

Substances

  • CNOT1 protein, human
  • Carrier Proteins
  • Drosophila Proteins
  • NOT1 protein, Drosophila
  • RC3H1 protein, human
  • RNA, Messenger
  • RNA-Binding Proteins
  • Recombinant Proteins
  • Transcription Factors
  • Ubiquitin-Protein Ligases
  • Ribonucleases
  • mRNA deadenylase