Activation of Gαi at the Golgi by GIV/Girdin imposes finiteness in Arf1 signaling.
Dev Cell
; 33(2): 189-203, 2015 Apr 20.
Article
en En
| MEDLINE
| ID: mdl-25865347
ABSTRACT
A long-held tenet of heterotrimeric G protein signal transduction is that it is triggered by G protein-coupled receptors (GPCRs) at the PM. Here, we demonstrate that Gi is activated in the Golgi by GIV/Girdin, a non-receptor guanine-nucleotide exchange factor (GEF). GIV-dependent activation of Gi at the Golgi maintains the finiteness of the cyclical activation of ADP-ribosylation factor 1 (Arf1), a fundamental step in vesicle traffic in all eukaryotes. Several interactions with other major components of Golgi trafficking-e.g., active Arf1, its regulator, ArfGAP2/3, and the adaptor protein ß-COP-enable GIV to coordinately regulate Arf1 signaling. When the GIV-Gαi pathway is selectively inhibited, levels of GTP-bound Arf1 are elevated and protein transport along the secretory pathway is delayed. These findings define a paradigm in non-canonical G protein signaling at the Golgi, which places GIV-GEF at the crossroads between signals gated by the trimeric G proteins and the Arf family of monomeric GTPases.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Subunidades alfa de la Proteína de Unión al GTP Gi-Go
/
Factor 1 de Ribosilacion-ADP
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Vesículas Transportadoras
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Proteínas de Transporte Vesicular
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Aparato de Golgi
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Proteínas de Microfilamentos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Dev Cell
Asunto de la revista:
EMBRIOLOGIA
Año:
2015
Tipo del documento:
Article
País de afiliación:
Estados Unidos