2. Academic Validation
  3. Molecular architecture of LSM14 interactions involved in the assembly of mRNA silencing complexes

Molecular architecture of LSM14 interactions involved in the assembly of mRNA silencing complexes

  • EMBO J. 2018 Apr 3;37(7):e97869. doi: 10.15252/embj.201797869.
Tobias Brandmann 1,  Hana Fakim 2 3,  Zoya Padamsi 2 3,  Ji-Young Youn 4 5,  Anne-Claude Gingras 4 5,  Marc R Fabian 6 3,  Martin Jinek 7
Affiliations

Affiliations

  • 1 Department of Biochemistry, University of Zurich, Zurich, Switzerland.
  • 2 Department of Oncology, McGill University, Montreal, QC, Canada.
  • 3 Segal Cancer Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada.
  • 4 Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.
  • 5 Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
  • 6 Department of Oncology, McGill University, Montreal, QC, Canada marc.fabian@mcgill.ca jinek@bioc.uzh.ch.
  • 7 Department of Biochemistry, University of Zurich, Zurich, Switzerland marc.fabian@mcgill.ca jinek@bioc.uzh.ch.
PMID: 29510985 DOI: 10.15252/embj.201797869
Abstract

The LSM domain-containing protein LSM14/Rap55 plays a role in mRNA decapping, translational repression, and RNA granule (P-body) assembly. How LSM14 interacts with the mRNA silencing machinery, including the eIF4E-binding protein 4E-T and the DEAD-box helicase DDX6, is poorly understood. Here we report the crystal structure of the LSM domain of LSM14 bound to a highly conserved C-terminal fragment of 4E-T. The 4E-T C-terminus forms a bi-partite motif that wraps around the N-terminal LSM domain of LSM14. We also determined the crystal structure of LSM14 bound to the C-terminal RecA-like domain of DDX6. LSM14 binds DDX6 via a unique non-contiguous motif with distinct directionality as compared to Other DDX6-interacting proteins. Together with mutational and proteomic studies, the LSM14-DDX6 structure reveals that LSM14 has adopted a divergent mode of binding DDX6 in order to support the formation of mRNA silencing complexes and P-body assembly.

Keywords

P‐bodies; SLIMs; mRNA decapping; protein–protein interaction networks; translational repression.

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