A5020467193- Cellular transport and secretion
- Protein Kinase Regulation and GTPase Signaling
- Receptor Mechanisms and Signaling
- Lipid Membrane Structure and Behavior
- Ion channel regulation and function
- Erythrocyte Function and Pathophysiology
- Nitric Oxide and Endothelin Effects
- Retinal Development and Disorders
- Bacterial Genetics and Biotechnology
- Calcium signaling and nucleotide metabolism
- Cellular Mechanics and Interactions
- Cell Adhesion Molecules Research
- Microtubule and mitosis dynamics
- Endoplasmic Reticulum Stress and Disease
- Barrier Structure and Function Studies
- Signaling Pathways in Disease
- RNA and protein synthesis mechanisms
- Connexins and lens biology
- Ubiquitin and proteasome pathways
- Caveolin-1 and cellular processes
- Glycosylation and Glycoproteins Research
- Enzyme Structure and Function
- Cardiomyopathy and Myosin Studies
- Bacterial biofilms and quorum sensing
- Hippo pathway signaling and YAP/TAZ
Centre National de la Recherche Scientifique
2007-2021
Institut de Pharmacologie Moléculaire et Cellulaire
2006-2021
Université Côte d'Azur
2008-2021
University of Naples Federico II
2014
Centre d’Immunologie de Marseille-Luminy
1998-1999
Inserm
1998-1999
Institut Curie
1998
Recombinant N-myristoylated bovine ADP-ribosylation factor 1 (myr-rARF1) has been expressed in bacteria and purified to near homogeneity with a high (85%) myristoylation efficiency. Myr-rARF1 nonmyristoylated rARF1 have compared respect their kinetics of guanine nucleotide exchange interactions phospholipids. Myristoylation is shown allow the release bound GDP at physiological (mM) concentrations Mg 2+. dissociation slow absence phospholipids but accelerated 2-fold presence phospholipid...
We have investigated the role of N-myristoylation in activation bovine ADP-ribosylation factor 1 (ARF1). previously showed that myristoylation allows some spontaneous GDP-to-GTP exchange to occur on ARF1 at physiological Mg2+ levels presence phospholipid vesicles (Franco, M., Chardin, P., Chabre, and Paris, S.(1995) J. Biol. Chem. 270, 1337-1341). Here, we report this basal nucleotide can be accelerated (by up 5-fold) by addition a soluble fraction obtained from retinas. This acceleration is...
Regulated cell polarity is central to many cellular processes. We investigated the mechanisms that govern rapid switching of (reversals) during motility bacterium Myxococcus xanthus. Cellular reversals are mediated by pole-to-pole oscillations proteins and frequency under control Frz chemosensory system. However, molecular mechanism creates dynamic remained be characterized. In this work, we establish polarization regulated GTP cycle a Ras-like GTPase, MglA. initially sought an MglA...
In Myxococcus xanthus the gliding motility machinery is assembled at leading cell pole to form focal adhesions, translocated rearward propel cell, and disassembled lagging pole. We show that MglA, a Ras-like small G-protein, an integral part of this machinery. function, MglA stimulates assembly complex by directly connecting it MreB actin cytoskeleton. Because nucleotide state regulated spatially only binds in guanosine triphosphate–bound form, complexes are dispersed where triphosphatase...
The small GTP-binding protein ADP-ribosylation factor 6 (Arf6) is involved in plasma membrane/endosomes trafficking. However, precisely how the activation of Arf6 regulates vesicular transport still unclear. Here, we show that, vitro, recombinant Arf6GTP recruits purified clathrin-adaptor complex AP-2 (but not AP-1) onto phospholipid liposomes absence phosphoinositides. We also that phosphoinositides and tightly cooperate to translocate membrane. In vivo, Arf6GDP) was found associated AP-2....
We recently reported the identification of EFA6 (exchange factor for ARF6), a brain-specific Sec7-domain-containing guanine nucleotide exchange that works specifically on ARF6. Here, we have characterized product broadly expressed gene encoding novel 1056 amino-acid protein named EFA6B. show EFA6B, which contains Sec7 domain is highly homologous to EFA6, as an ARF6-specific in vitro. Like will be referred EFA6A from now on, EFA6B involved membrane recycling and colocalizes with ARF6...
Budding of transport vesicles in the Golgi apparatus requires recruitment coat proteins and is regulated by ADP ribosylation factor (ARF) 1. ARF1 activation promoted guanine nucleotide exchange factors (GEFs), which catalyze transition to GTP-bound ARF1. We recently have identified a human protein, ARNO (ARF nucleotide-binding-site opener), as an ARF1-GEF that shares conserved domain with yeast Sec7 protein. now describe domain-containing GEF referred ARNO3. ARNO3, well third called...
The function of Arf6 has been investigated largely by using the T27N and Q67L mutants, which are thought to be blocked in GDP- GTP-bound states, respectively. However, these mutants have poorly characterized biochemically. Here, we found that Arf6(T27N) is not an appropriate marker inactive GDP-bound form because it a high tendency lose its nucleotide vitro denature. As consequence, most protein aggregated vivo localizes detergent-insoluble structures. small proportion able stable complex...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRoles of Lipid Modifications Transducin Subunits in Their GDP-Dependent Association and Membrane BindingJoelle Bigay, Eva Faurobert, Michel Franco, Marc ChabreCite this: Biochemistry 1994, 33, 47, 14081–14090Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994https://pubs.acs.org/doi/10.1021/bi00251a017https://doi.org/10.1021/bi00251a017research-articleACS PublicationsRequest reuse...
ARF1 and ARF6 are distant members of the ADP-ribosylation factor (ARF) small G-protein subfamily. Their distinct cellular functions must result from specificity interaction with different effectors regulators, including guanine nucleotide exchange factors (GEFs). ARF nucleotide-binding site opener (ARNO), EFA6 analogous ARF-GEFs, both comprising a catalytic "Sec7" domain pleckstrin homology domain. In vivo ARNO, like ARF1, is mostly cytosolic, minor localizations at Golgi plasma membrane;...
We addressed the role of EFA6, exchange factor for ARF6, during development epithelial cell polarity in Madin-Darby canine kidney cells. EFA6 is located primarily at apical pole polarized cells, including plasma membrane. After calcium-triggered E-cadherin-mediated adhesion, recruited to a Triton X-100-insoluble fraction and its protein level increased concomitantly accelerated formation functional tight junction (TJ). The expression results selective retention surface TJ occludin. This...
The Arf6-specific exchange factor EFA6 coordinates membrane trafficking with actin cytoskeleton remodeling. It localizes to the plasma where it catalyzes Arf6 activation and induces formation of actin-based ruffles. We have shown previously that pleckstrin homology (PH) domain was responsible for its localization. In this study we looked partners PH at membrane. Mutations conserved basic residues suspected be involved in binding phosphoinositides redistribute EFA6-PH cytosol. addition,...
β2-adrenergic receptor (β2AR), a member of the GPCR (G-Proteins Coupled Receptor) family, is internalized in ligand- and β-arrestin-dependent manner into early endosomes, subsequently recycled back to plasma membrane. Here we report that β-arrestin promotes activation small G protein Arf6, which regulates recycling degradation β2AR. We demonstrate vitro C-terminal region β-arrestin1 interacted directly simultaneously with Arf6GDP its specific exchange factor EFA6, promote Arf6 activation....
Significance EFA6, cytohesins, and BRAGs activate Arf GTPases in endocytic events. They carry a plasma membrane-binding PH domain tandem with their catalytic Sec7 domain, which is autoinhibitory mediates positive feedback loop cytohesins but not BRAGs, has an as-yet unknown role EFA6 regulation. By reconstituting GDP/GTP exchange on membranes, we find that the of autoinhibitory, supports negative loop. This controlled by interaction Arf6-GTP PH-Ct domains monitors Arf1 Arf6 activation...
Membrane binding of ADP-ribosylation factors (ARFs) is GTP-dependent and seems to require amino-terminal myristoylation. Recently it has been proposed that myristoylation needed not for the activation ARF by GTP but its subsequent association membranes. Here we show unmyristoylated bovine ARF1, expressed in bacteria, can be efficiently loaded with gamma S (guanosine 5'-O-(thio)triphosphate) at 1 microM free Mg2+, presence phospholipids. Unmyristoylated ARFGTP cosediments phospholipid...