Model for the roles of Brag2 and Dock180 in cell–cell fusion. Upon receipt of signals from fusion receptors on the cell surface Brag2 activates ARF6, which in turn transports paxillin to sites of focal adhesion, where it complexes with integrins thereby maintaining the structural integrity required during myotube maturation. Dock180 regulates Rac-GTP activity thus primarily contributing to lamellipodia formation and cytoskeletal rearrangement. Dock180 can activate ARF6, thus in part functioning in paxillin transport and possibly integrin recycling.