The E3 ubiquitin-ligase HACE1 catalyzes the ubiquitylation of active Rac1.
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Torrino S, Visvikis O, Doye A, Boyer L, Stefani C, Munro P, Bertoglio J, Gacon G, Mettouchi A, Lemichez E
The E3 ubiquitin-ligase HACE1 catalyzes the ubiquitylation of active Rac1.
Dev Cell. 2011 Nov 15;21(5):959-65. doi: 10.1016/j.devcel.2011.08.015. Epub 2011 Oct 27.
- PubMed ID
- 22036506 [ View in PubMed]
- Abstract
Rac1 small GTPase controls essential aspects of cell biology and is a direct target of numerous bacterial virulence factors. The CNF1 toxin of pathogenic Escherichia coli addresses Rac1 to ubiquitin-proteasome system (UPS). We report the essential role of the tumor suppressor HACE1, a HECT-domain containing E3 ubiquitin-ligase, in the targeting of Rac1 to UPS. HACE1 binds preferentially GTP-bound Rac1 and catalyzes its polyubiquitylation. HACE1 expression increases the ubiquitylation of Rac1, when the GTPase is activated by point mutations or by the GEF-domain of Dbl. RNAi-mediated depletion of HACE1 blocks the ubiquitylation of active Rac1 and increases GTP-bound Rac1 cellular levels. HACE1 antagonizes cell isotropic spreading, a hallmark of Rac1 activation, and is required for endothelial cell monolayer invasion by bacteria. Together, these data establish the role of the HACE1 E3 ubiquitin-ligase in controlling Rac1 ubiquitylation and activity.