Pharmaceuticals (Feb 2022)

The p97 Inhibitor UPCDC-30245 Blocks Endo-Lysosomal Degradation

  • Feng Wang,
  • Shan Li,
  • Kai-Wen Cheng,
  • William M. Rosencrans,
  • Tsui-Fen Chou

DOI
https://doi.org/10.3390/ph15020204
Journal volume & issue
Vol. 15, no. 2
p. 204

Abstract

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The diverse modes of action of small molecule inhibitors provide versatile tools to investigate basic biology and develop therapeutics. However, it remains a challenging task to evaluate their exact mechanisms of action. We identified two classes of inhibitors for the p97 ATPase: ATP competitive and allosteric. We showed that the allosteric p97 inhibitor, UPCDC-30245, does not affect two well-known cellular functions of p97, endoplasmic-reticulum-associated protein degradation and the unfolded protein response pathway; instead, it strongly increases the lipidated form of microtubule-associated proteins 1A/1B light chain 3B (LC3-II), suggesting an alteration of autophagic pathways. To evaluate the molecular mechanism, we performed proteomic analysis of UPCDC-30245 treated cells. Our results revealed that UPCDC-30245 blocks endo-lysosomal degradation by inhibiting the formation of early endosome and reducing the acidity of the lysosome, an effect not observed with the potent p97 inhibitor CB-5083. This unique effect allows us to demonstrate UPCDC-30245 exhibits antiviral effects against coronavirus by blocking viral entry.

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