A comprehensive phenotypic CRISPR-Cas9 screen of the ubiquitin pathway uncovers roles of ubiquitin ligases in mitosis

Mol Cell. 2021 Mar 18;81(6):1319-1336.e9. doi: 10.1016/j.molcel.2021.01.014. Epub 2021 Feb 3.


The human ubiquitin proteasome system, composed of over 700 ubiquitin ligases (E3s) and deubiquitinases (DUBs), has been difficult to characterize systematically and phenotypically. We performed chemical-genetic CRISPR-Cas9 screens to identify E3s/DUBs whose loss renders cells sensitive or resistant to 41 compounds targeting a broad range of biological processes, including cell cycle progression, genome stability, metabolism, and vesicular transport. Genes and compounds clustered functionally, with inhibitors of related pathways interacting similarly with E3s/DUBs. Some genes, such as FBXW7, showed interactions with many of the compounds. Others, such as RNF25 and FBXO42, showed interactions primarily with a single compound (methyl methanesulfonate for RNF25) or a set of related compounds (the mitotic cluster for FBXO42). Mutation of several E3s with sensitivity to mitotic inhibitors led to increased aberrant mitoses, suggesting a role for these genes in cell cycle regulation. Our comprehensive CRISPR-Cas9 screen uncovered 466 gene-compound interactions covering 25% of the interrogated E3s/DUBs.

Keywords: CRISPR-Cas9 screen; DUB; E3 ubiquitin ligase; FBXO42; mitosis; ubiquitin.

Publication types

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

MeSH terms

  • CRISPR-Cas Systems*
  • Cell Line
  • Humans
  • Mitosis*
  • Signal Transduction*
  • Ubiquitin* / genetics
  • Ubiquitin* / metabolism
  • Ubiquitin-Protein Ligases* / genetics
  • Ubiquitin-Protein Ligases* / metabolism


  • Ubiquitin
  • Ubiquitin-Protein Ligases