Molecular basis of ubiquitin-specific protease 8 autoinhibition by the WW-like domain

Commun Biol. 2021 Nov 8;4(1):1272. doi: 10.1038/s42003-021-02802-x.


Ubiquitin-specific protease 8 (USP8) is a deubiquitinating enzyme involved in multiple membrane trafficking pathways. The enzyme activity is inhibited by binding to 14-3-3 proteins. Mutations in the 14-3-3-binding motif in USP8 are related to Cushing's disease. However, the molecular basis of USP8 activity regulation remains unclear. This study identified amino acids 645-684 of USP8 as an autoinhibitory region, which might interact with the catalytic USP domain, as per the results of pull-down and single-molecule FRET assays performed in this study. In silico modelling indicated that the region forms a WW-like domain structure, plugs the catalytic cleft, and narrows the entrance to the ubiquitin-binding pocket. Furthermore, 14-3-3 inhibited USP8 activity partly by enhancing the interaction between the WW-like and USP domains. These findings provide the molecular basis of USP8 autoinhibition via the WW-like domain. Moreover, they suggest that the release of autoinhibition may underlie Cushing's disease due to USP8 mutations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Endopeptidases / genetics*
  • Endopeptidases / metabolism
  • Endosomal Sorting Complexes Required for Transport / genetics*
  • Endosomal Sorting Complexes Required for Transport / metabolism
  • Humans
  • Mutation*
  • Pituitary ACTH Hypersecretion / genetics*
  • Ubiquitin Thiolesterase / genetics*
  • Ubiquitin Thiolesterase / metabolism
  • Ubiquitination


  • Endosomal Sorting Complexes Required for Transport
  • Endopeptidases
  • USP8 protein, human
  • Ubiquitin Thiolesterase