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bioRxiv · 10.1101/2020.05.18.103085

Seesaw Conformations of Npl4 in the Human p97 Complex and the Inhibitory Mechanism of a Disulfiram Derivative

Pan, M.·Zheng, Q.·Yu, Y.·Ai, H.·Xie, Y.·Zeng, X.·Wang, C.·Liu, L.·Zhao, M.
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Abstract

p97, also known as valosin-containing protein (VCP) or Cdc48, plays a central role in cellular protein homeostasis1. Human p97 mutations are associated with several neurodegenerative diseases2,3. Targeting p97 and its cofactors is a strategy for cancer drug development4. Despite significant structural insights into the fungal homolog Cdc485-7, little is known about how human p97 interacts with its cofactors. Recently, the anti-alcohol abuse drug disulfiram was found to target cancer through Npl4, a cofactor of p978, but the molecular mechanism remains elusive. Here, using single-particle cryo-electron microscopy (cryo-EM), we uncovered three Npl4 conformational states in complex with human p97 before ATP hydrolysis. The motion of Npl4 results from its zinc finger motifs interacting with the N domain of p97, which is essential for the unfolding activity of p97. In vitro and cell-based assays showed that under oxidative conditions, the disulfiram derivative bis-(diethyldithiocarbamate)-copper (CuET) inhibits p97 function by releasing cupric ions, which disrupt the zinc finger motifs of Npl4, locking the essential conformational switch of the complex.

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Pan, M., Zheng, Q., Yu, Y., Ai, H., Xie, Y., Zeng, X., Wang, C., Liu, L., Zhao, M.. 2020-05-20. Seesaw Conformations of Npl4 in the Human p97 Complex and the Inhibitory Mechanism of a Disulfiram Derivative. https://doi.org/10.1101/2020.05.18.103085

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