SENP8 limits aberrant neddylation of NEDD8 pathway components to promote cullin- 1 RING ubiquitin ligase function
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ABSTRACT: NEDD8 is a ubiquitin-like modifier most well-studied for its role in activating the largest family of ubiquitin E3 ligases, the cullin-RING ligases (CRLs). While many non-cullin neddylation substrates have been proposed over the years, validation of true NEDD8 targets has been challenging, as overexpression of exogenous NEDD8 can trigger NEDD8 conjugation through the ubiquitylation machinery. Here, we developed a deconjugation-resistant form of NEDD8 to stabilize the neddylated form of cullins and other non-cullin substrates. Using this strategy, we identified Ubc12, a NEDD8-specific E2 conjugating enzyme, as a substrate for auto-neddylation both in vitro and in cells. Furthermore, we identified SENP8/DEN1 as the protease that counteracts Ubc12 auto-neddylation, and observed aberrant neddylation of Ubc12 and other NEDD8 conjugation pathway components in engineered SENP8-deficient cells. Importantly, loss of SENP8 function contributes to reduced CRL activity, accumulation of CRL substrates, and defective cell cycle progression. Thus, our study highlights the importance of SENP8 in maintaining proper neddylation levels and CRL-dependent proteostasis, implicating this protease as a potential therapeutic target for inhibiting CRL activity.
INSTRUMENT(S): Q Exactive
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: Beatrix Ueberheide
PROVIDER: MSV000080917 | MassIVE | Thu Apr 13 05:37:00 BST 2017
SECONDARY ACCESSION(S): PXD006288
REPOSITORIES: MassIVE
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