The RanBP2/RanGAP1∗SUMO1/Ubc9 complex is a multisubunit SUMO E3 ligase

Summary: RanBP2/Nup358 is an essential protein with roles in nuclear transport and mitosis, and is one of the few known SUMO E3 ligases. However, why RanBP2 functions in vivo has been unclear: throughout the cell cycle it stably interacts with RanGAP1∗SUMO1 and Ubc9, whose binding sites overlap wit...

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Hauptverfasser: Werner, Andreas (VerfasserIn) , Flotho, Annette (VerfasserIn) , Melchior, Frauke (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 29 March 2012
In: Molecular cell
Year: 2012, Jahrgang: 46, Heft: 3, Pages: 287-298
ISSN:1097-4164
DOI:10.1016/j.molcel.2012.02.017
Online-Zugang:Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1016/j.molcel.2012.02.017
Verlag, kostenfrei, Volltext: http://www.sciencedirect.com/science/article/pii/S1097276512001761
Volltext
Verfasserangaben:Andreas Werner, Annette Flotho, and Frauke Melchior
Beschreibung
Zusammenfassung:Summary: RanBP2/Nup358 is an essential protein with roles in nuclear transport and mitosis, and is one of the few known SUMO E3 ligases. However, why RanBP2 functions in vivo has been unclear: throughout the cell cycle it stably interacts with RanGAP1∗SUMO1 and Ubc9, whose binding sites overlap with the E3 ligase region. Here we show that cellular RanBP2 is quantitatively associated with RanGAP1, indicating that complexed rather than free RanBP2 is the relevant E3 ligase. Biochemical reconstitution of the RanBP2/RanGAP1∗SUMO1/Ubc9 complex enabled us to characterize its activity on the endogenous substrate Borealin. We find that the complex is a composite E3 ligase rather than an E2-E3 complex, and demonstrate that complex formation induces activation of a catalytic site that shows no activity in free RanBP2. Our findings provide insights into the mechanism of an important E3 ligase, and extend the concept of multisubunit E3 ligases from ubiquitin to the SUMO field.
Beschreibung:Gesehen am 31.08.2018
Beschreibung:Online Resource
ISSN:1097-4164
DOI:10.1016/j.molcel.2012.02.017