Potent, Reversible, and Specific Chemical Inhibitors of Eukaryotic Ribosome Biogenesis

Cell. 2016 Oct 6;167(2):512-524.e14. doi: 10.1016/j.cell.2016.08.070. Epub 2016 Sep 22.


All cellular proteins are synthesized by ribosomes, whose biogenesis in eukaryotes is a complex multi-step process completed within minutes. Several chemical inhibitors of ribosome function are available and used as tools or drugs. By contrast, we lack potent validated chemical probes to analyze the dynamics of eukaryotic ribosome assembly. Here, we combine chemical and genetic approaches to discover ribozinoindoles (or Rbins), potent and reversible triazinoindole-based inhibitors of eukaryotic ribosome biogenesis. Analyses of Rbin sensitivity and resistance conferring mutations in fission yeast, along with biochemical assays with recombinant proteins, provide evidence that Rbins' physiological target is Midasin, an essential ∼540-kDa AAA+ (ATPases associated with diverse cellular activities) protein. Using Rbins to acutely inhibit or activate Midasin function, in parallel experiments with inhibitor-sensitive or inhibitor-resistant cells, we uncover Midasin's role in assembling Nsa1 particles, nucleolar precursors of the 60S subunit. Together, our findings demonstrate that Rbins are powerful probes for eukaryotic ribosome assembly.

Keywords: AAA(+) protein; Midasin; Schizosaccharomyces pombe; chemical genetics; chemical inhibitors; chemical screen; fission yeast; ribosome biogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / antagonists & inhibitors*
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / isolation & purification
  • Enzyme Inhibitors / pharmacology*
  • Indoles / chemistry
  • Indoles / isolation & purification
  • Indoles / pharmacology*
  • Ribosome Subunits, Large, Eukaryotic / drug effects*
  • Ribosome Subunits, Large, Eukaryotic / metabolism*
  • Schizosaccharomyces / drug effects
  • Schizosaccharomyces / metabolism
  • Schizosaccharomyces pombe Proteins / antagonists & inhibitors*
  • Structure-Activity Relationship
  • Triazines / chemistry
  • Triazines / isolation & purification
  • Triazines / pharmacology*


  • Enzyme Inhibitors
  • Indoles
  • Schizosaccharomyces pombe Proteins
  • Triazines
  • Adenosine Triphosphatases