siRNA screen identifies QPCT as a druggable target for Huntington's disease

Nat Chem Biol. 2015 May;11(5):347-354. doi: 10.1038/nchembio.1790. Epub 2015 Apr 6.


Huntington's disease (HD) is a currently incurable neurodegenerative condition caused by an abnormally expanded polyglutamine tract in huntingtin (HTT). We identified new modifiers of mutant HTT toxicity by performing a large-scale 'druggable genome' siRNA screen in human cultured cells, followed by hit validation in Drosophila. We focused on glutaminyl cyclase (QPCT), which had one of the strongest effects on mutant HTT-induced toxicity and aggregation in the cell-based siRNA screen and also rescued these phenotypes in Drosophila. We found that QPCT inhibition induced the levels of the molecular chaperone αB-crystallin and reduced the aggregation of diverse proteins. We generated new QPCT inhibitors using in silico methods followed by in vitro screening, which rescued the HD-related phenotypes in cell, Drosophila and zebrafish HD models. Our data reveal a new HD druggable target affecting mutant HTT aggregation and provide proof of principle for a discovery pipeline from druggable genome screen to drug development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminoacyltransferases / antagonists & inhibitors
  • Aminoacyltransferases / drug effects*
  • Aminoacyltransferases / genetics*
  • Animals
  • Cells, Cultured
  • Computational Biology
  • Drosophila
  • Drug Evaluation, Preclinical
  • Enzyme Inhibitors / pharmacology
  • Enzyme Inhibitors / therapeutic use
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Huntingtin Protein
  • Huntington Disease / drug therapy*
  • Huntington Disease / genetics*
  • Mice
  • Mice, Inbred C57BL
  • Mutation / genetics
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Neurons / drug effects
  • Neurons / metabolism
  • RNA, Small Interfering*
  • Zebrafish
  • alpha-Crystallin B Chain / metabolism


  • Enzyme Inhibitors
  • HTT protein, human
  • Huntingtin Protein
  • Nerve Tissue Proteins
  • RNA, Small Interfering
  • alpha-Crystallin B Chain
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Aminoacyltransferases
  • glutaminyl-peptide cyclotransferase

Associated data

  • PubChem-Substance/249494159
  • PubChem-Substance/249494160
  • PubChem-Substance/249494161
  • PubChem-Substance/249494162
  • PubChem-Substance/249494163
  • PubChem-Substance/249494164
  • PubChem-Substance/249494165
  • PubChem-Substance/249494166
  • PubChem-Substance/249494167
  • PubChem-Substance/249494168