RNF4 is a poly-SUMO-specific E3 ubiquitin ligase required for arsenic-induced PML degradation
Résumé
In acute promyelocytic leukaemia (APL), promyelocytic leukaemia (PML) protein is fused to the retinoic acid receptor α (RAR). This disease can be treated effectively with arsenic, which induces PML modification by small ubiquitin-like modifiers (SUMO) and proteasomal degradation. Here we demonstrate that the RING-domain-containing ubiquitin E3 ligase, RNF4 (SNURF), targets poly-SUMO-modified proteins for degradation mediated by ubiquitin. RNF4 depletion or proteasome inhibition led to accumulation of mixed, polyubiquitinated, poly-SUMO chains. In RNF4-depleted cells, PML protein accumulated and was ubiquitinated by RNF4 in a SUMO-dependent fashion in vitro. In the absence of RNF4, arsenic failed to induce degradation of PML and SUMO-modified PML accumulated in the nucleus. These results demonstrate that poly-SUMO chains can act as discrete signals from mono-SUMOylation, in this case targeting a poly-SUMOylated substrate for ubiquitin-mediated proteolysis.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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