QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 20, Issue 3, 859-869, February 1, 2009

This Article Full Text Full Text (PDF) Supplemental Materials All Versions of this Article: E08-10-1010v1 20/3/859    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kliouchnikov, L. Articles by Cassel, D. Search for Related Content PubMed PubMed Citation Articles by Kliouchnikov, L. Articles by Cassel, D.

Discrete Determinants in ArfGAP2/3 Conferring Golgi Localization and Regulation by the COPI Coat

Lena Kliouchnikov^*, Joëlle Bigay, Bruno Mesmin, Anna Parnis^*, Moran Rawet^*, Noga Goldfeder^*, Bruno Antonny, and Dan Cassel^*

*Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel; and Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis et Centre National de la Recherche Scientifique, 06560 Valbonne, France

Submitted October 8, 2008; Revised December 2, 2008; Accepted December 4, 2008
Monitoring Editor: Akihiko Nakano

InCytes from MBC

From yeast to mammals, two types of GTPase-activating proteins, ArfGAP1 and ArfGAP2/3, control guanosine triphosphate (GTP) hydrolysis on the small G protein ADP-ribosylation factor (Arf) 1 at the Golgi apparatus. Although functionally interchangeable, they display little similarity outside the catalytic GTPase-activating protein (GAP) domain, suggesting differential regulation. ArfGAP1 is controlled by membrane curvature through its amphipathic lipid packing sensor motifs, whereas Golgi targeting of ArfGAP2 depends on coatomer, the building block of the COPI coat. Using a reporter fusion approach and in vitro assays, we identified several functional elements in ArfGAP2/3. We show that the Golgi localization of ArfGAP3 depends on both a central basic stretch and a carboxy-amphipathic motif. The basic stretch interacts directly with coatomer, which we found essential for the catalytic activity of ArfGAP3 on Arf1-GTP, whereas the carboxy-amphipathic motif interacts directly with lipid membranes but has minor role in the regulation of ArfGAP3 activity. Our findings indicate that the two types of ArfGAP proteins that reside at the Golgi use a different combination of protein–protein and protein–lipid interactions to promote GTP hydrolysis in Arf1-GTP.

Address correspondence to: Dan Cassel (danc{at}tx.technion.ac.il)

Abbreviations used: Arf, ADP-ribosylation factor; ALPS, amphipathic lipid packing sensor; GAP, GTPase-activating protein.

This article has been cited by other articles:

				A. Saitoh, H.-W. Shin, A. Yamada, S. Waguri, and K. Nakayama Three Homologous ArfGAPs Participate in Coat Protein I-mediated Transport J. Biol. Chem., May 15, 2009; 284(20): 13948 - 13957. [Abstract] [Full Text] [PDF]