title: ADP-ribosylation factor 6 regulates mammalian myoblast fusion through phospholipase D1 and phosphatidylinositol 4,5-bisphosphate signaling pathways.
abstract: Myoblast fusion is an essential step during myoblast differentiation that remains poorly understood. M-cadherin-dependent pathways that signal through Rac1 GTPase activation via the Rho-guanine nucleotide exchange factor (GEF) Trio are important for myoblast fusion. The ADP-ribosylation factor (ARF)6 GTPase has been shown to bind to Trio and to regulate Rac1 activity. Moreover, Loner/GEP(100)/BRAG2, a GEF of ARF6, has been involved in mammalian and Drosophila myoblast fusion, but the specific role of ARF6 has been not fully analyzed. Here, we show that ARF6 activity is increased at the time of myoblast fusion and is required for its implementation in mouse C2C12 myoblasts. Specifically, at the onset of myoblast fusion, ARF6 is associated with the multiproteic complex that contains M-cadherin, Trio, and Rac1 and accumulates at sites of myoblast fusion. ARF6 silencing inhibits the association of Trio and Rac1 with M-cadherin. Moreover, we demonstrate that ARF6 regulates myoblast fusion through phospholipase D (PLD) activation and phosphatidylinositol 4,5-bis-phosphate production. Together, these data indicate that ARF6 is a critical regulator of C2C12 myoblast fusion and participates in the regulation of PLD activities that trigger both phospholipids production and actin cytoskeleton reorganization at fusion sites.
authors.affiliation: Universités Montpellier 2 et 1, Centre de Recherche en Biochimie Macromoléculaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5237, Institut Fédératif de Recherche 122 1919 Route de Mende, 34293 Montpellier, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Bach
authors.forename: Sandrine
authors.initials: S
authors.lastname: Enjalbert
authors.forename: Franck
authors.initials: F
authors.lastname: Comunale
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bodin
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vitale
authors.forename: Sophie
authors.initials: S
authors.lastname: Charrasse
authors.forename: Cécile
authors.initials: C
authors.lastname: Gauthier-Rouvière
mesh_terms: D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002459:Cell Fusion; D002460:Cell Line; D004789:Enzyme Activation; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D051379:Mice; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology; D032446:Myoblasts / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021381:Protein Transport; D012038:Regeneration; D015398:Signal Transduction; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D000089982:ADP-Ribosylation Factor 6; D015820:Cadherins; D020662:Guanine Nucleotide Exchange Factors; D019269:Phosphatidylinositol 4,5-Diphosphate; D010750:Phosphoproteins; C490975:Trio protein, mouse; D017346:Protein Serine-Threonine Kinases; D010739:Phospholipase D; C106801:phospholipase D1; D020727:ADP-Ribosylation Factors; C000715727:Arf6 protein, mouse; D020830:rac1 GTP-Binding Protein