The hGIDGID4E3 ubiquitin ligase complex targets ARHGAP11A to regulate cell migration

• DOI: 10.26508/lsa.202403046
• Publication Date: 2024-10-10T19:50:16Z
• Authors: Halil Bagci; Martin Winkler; Benjamin Grädel; Federico Uliana; Jonathan Boulais; Weaam I Mohamed; Sophia L Park; Jean-François Côté; Olivier Pertz; Matthias Peter
• Keywords: HEK293 Cells; Cell Movement; Ubiquitin-Protein Ligases; GTPase-Activating Proteins; Proteolysis; Ubiquitination; Humans; rhoA GTP-Binding Protein; Research Articles; Protein Binding

The human CTLH/GID (hGID) complex emerged as an important E3 ligase regulating multiple cellular processes, including cell cycle progression and metabolism. However, the range of biological functions controlled by hGID remains unexplored. Here, we used proximity-dependent biotinylation (BioID2) to identify proteins interacting with the hGID complex, among them, substrate candidates that bind GID4 in a pocket-dependent manner. Biochemical and cellular assays revealed that the hGIDGID4E3 ligase binds and ubiquitinates ARHGAP11A, thereby targeting this RhoGAP for proteasomal degradation. Indeed, GID4 depletion or impeding the GID4 substrate binding pocket with the PFI-7 inhibitor stabilizes ARHGAP11A protein amounts, although it carries no functional N-terminal degron. Interestingly, GID4 inactivation impairs cell motility and directed cell movement by increasing ARHGAP11A levels at the cell periphery, where it inactivates RhoA. Together, we identified a wide range of hGIDGID4E3 ligase substrates and uncovered a unique function of the hGIDGID4E3 ligase regulating cell migration by targeting ARHGAP11A.