The human GID complex engages two independent modules for substrate recruitment.

Autor: Mohamed WI; Institute of Biochemistry, Department of Biology, ETH Zürich, Zürich, Switzerland., Park SL; Institute of Biochemistry, Department of Biology, ETH Zürich, Zürich, Switzerland.; Life Science Zürich, PhD Program for Molecular Life Sciences, Zürich, Switzerland., Rabl J; Cryo-EM Knowledge Hub (CEMK), Zürich, Switzerland., Leitner A; Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, Zürich, Switzerland., Boehringer D; Cryo-EM Knowledge Hub (CEMK), Zürich, Switzerland., Peter M; Institute of Biochemistry, Department of Biology, ETH Zürich, Zürich, Switzerland.
Jazyk: angličtina
Zdroj: EMBO reports [EMBO Rep] 2021 Nov 04; Vol. 22 (11), pp. e52981. Date of Electronic Publication: 2021 Oct 14.
DOI: 10.15252/embr.202152981
Abstrakt: The human GID (hGID) complex is a conserved E3 ubiquitin ligase regulating diverse biological processes, including glucose metabolism and cell cycle progression. However, the biochemical function and substrate recognition of the multi-subunit complex remain poorly understood. Using biochemical assays, cross-linking mass spectrometry, and cryo-electron microscopy, we show that hGID engages two distinct modules for substrate recruitment, dependent on either WDR26 or GID4. WDR26 and RanBP9 cooperate to ubiquitinate HBP1 in vitro, while GID4 is dispensable for this reaction. In contrast, GID4 functions as an adaptor for the substrate ZMYND19, which surprisingly lacks a Pro/N-end degron. GID4 substrate binding and ligase activity is regulated by ARMC8α, while the shorter ARMC8β isoform assembles into a stable hGID complex that is unable to recruit GID4. Cryo-EM reconstructions of these hGID complexes reveal the localization of WDR26 within a ring-like, tetrameric architecture and suggest that GID4 and WDR26/Gid7 utilize different, non-overlapping binding sites. Together, these data advance our mechanistic understanding of how the hGID complex recruits cognate substrates and provides insights into the regulation of its E3 ligase activity.
(© 2021 The Authors. Published under the terms of the CC BY NC ND 4.0 license.)
Databáze: MEDLINE
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