Arf activation at the Golgi is modulated by feed-forward stimulation of the exchange factor GBF1

Gespeichert in:

Bibliographische Detailangaben
Zeitschriftentitel:	Journal of Cell Science
Personen und Körperschaften:	Quilty, Douglas, Gray, Fraser, Summerfeldt, Nathan, Cassel, Dan, Melançon, Paul
In:	Journal of Cell Science, 2013
Format:	E-Article
Sprache:	Englisch
veröffentlicht:	The Company of Biologists
Schlagwörter:	Cell Biology

Details
Zusammenfassung:	<jats:p>ADP-ribosylation factors (Arfs) play central roles in the regulation of vesicular trafficking through the Golgi. Arfs are activated at the Golgi membrane by guanine nucleotide exchange factors (GEFs) that are recruited from cytosol. Here, we describe a novel mechanism for regulation of recruitment and activity of the ArfGEF Golgi-specific BFA resistance factor 1 (GBF1). Conditions that alter the cellular Arf•GDP/Arf•GTP ratio result in GBF1 recruitment. This recruitment of GBF1 occurs selectively on cis-Golgi membranes in direct response to increased Arf•GDP. GBF1 recruitment requires Arf•GDP myristoylation-dependent interactions suggesting regulation of a membrane bound factor. Once recruited, GBF1 causes increased Arf•GTP production at the Golgi, consistent with a feed-forward, self-limiting mechanism of Arf activation. This mechanism is proposed to maintain steady-state levels of Arf•GTP at the cis-Golgi during cycles of Arf-dependent trafficking events.</jats:p>
ISSN:	1477-9137 0021-9533
DOI:	10.1242/jcs.130591