A gene-expression screen identifies a non-toxic sumoylation inhibitor that mimics SUMO-less human LRH-1 in liver

Elife. 2015 Dec 11;4:e09003. doi: 10.7554/eLife.09003.

Abstract

SUMO-modification of nuclear proteins has profound effects on gene expression. However, non-toxic chemical tools that modulate sumoylation in cells are lacking. Here, to identify small molecule sumoylation inhibitors we developed a cell-based screen that focused on the well-sumoylated substrate, human Liver Receptor Homolog-1 (hLRH-1, NR5A2). Our primary gene-expression screen assayed two SUMO-sensitive transcripts, APOC3 and MUC1, that are upregulated by SUMO-less hLRH-1 or by siUBC9 knockdown, respectively. A polyphenol, tannic acid (TA) emerged as a potent sumoylation inhibitor in vitro (IC50 = 12.8 µM) and in cells. TA also increased hLRH-1 occupancy on SUMO-sensitive transcripts. Most significantly, when tested in humanized mouse primary hepatocytes, TA inhibits hLRH-1 sumoylation and induces SUMO-sensitive genes, thereby recapitulating the effects of expressing SUMO-less hLRH-1 in mouse liver. Our findings underscore the benefits of phenotypic screening for targeting post-translational modifications, and illustrate the potential utility of TA for probing the cellular consequences of sumoylation.

Keywords: NASH; NR5As; cell biology; human; human biology; medicine; mouse; phenotypic screen; primary hepatocytes; sumoylation; tannic acid.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Drug Evaluation, Preclinical / methods
  • Enzyme Inhibitors / isolation & purification*
  • Enzyme Inhibitors / metabolism*
  • Gene Expression Profiling
  • Hepatocytes / drug effects*
  • Hepatocytes / enzymology
  • Humans
  • Inhibitory Concentration 50
  • Mice
  • Mice, SCID
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Sumoylation / drug effects*
  • Tannins / isolation & purification*
  • Tannins / metabolism*

Substances

  • Enzyme Inhibitors
  • NR5A2 protein, human
  • Receptors, Cytoplasmic and Nuclear
  • Tannins