The RNA-binding protein Gemin5 binds directly to the ribosome and regulates global translation

Nucleic Acids Res. 2016 Sep 30;44(17):8335-51. doi: 10.1093/nar/gkw702. Epub 2016 Aug 9.


RNA-binding proteins (RBPs) play crucial roles in all organisms. The protein Gemin5 harbors two functional domains. The N-terminal domain binds to snRNAs targeting them for snRNPs assembly, while the C-terminal domain binds to IRES elements through a non-canonical RNA-binding site. Here we report a comprehensive view of the Gemin5 interactome; most partners copurified with the N-terminal domain via RNA bridges. Notably, Gemin5 sediments with the subcellular ribosome fraction, and His-Gemin5 binds to ribosome particles via its N-terminal domain. The interaction with the ribosome was lost in F381A and Y474A Gemin5 mutants, but not in W14A and Y15A. Moreover, the ribosomal proteins L3 and L4 bind directly with Gemin5, and conversely, Gemin5 mutants impairing the binding to the ribosome are defective in the interaction with L3 and L4. The overall polysome profile was affected by Gemin5 depletion or overexpression, concomitant to an increase or a decrease, respectively, of global protein synthesis. Gemin5, and G5-Nter as well, were detected on the polysome fractions. These results reveal the ribosome-binding capacity of the N-ter moiety, enabling Gemin5 to control global protein synthesis. Our study uncovers a crosstalk between this protein and the ribosome, and provides support for the view that Gemin5 may control translation elongation.

MeSH terms

  • Cell Extracts
  • Chromatography, Affinity
  • HEK293 Cells
  • Humans
  • Mass Spectrometry
  • Models, Biological
  • Polyribosomes / metabolism
  • Protein Binding
  • Protein Biosynthesis*
  • Protein Domains
  • RNA / metabolism
  • RNA, Small Interfering / metabolism
  • RNA-Binding Proteins / metabolism*
  • Ribonucleoproteins, Small Nuclear / chemistry
  • Ribonucleoproteins, Small Nuclear / metabolism*
  • Ribosomal Proteins / metabolism
  • Ribosome Subunits, Large, Eukaryotic
  • Ribosomes / metabolism*
  • SMN Complex Proteins


  • Cell Extracts
  • GEMIN5 protein, human
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • Ribonucleoproteins, Small Nuclear
  • Ribosomal Proteins
  • SMN Complex Proteins
  • RNA