FIGURE 5.

A proposed mechanistic model for enhancement and inhibition of SNARE-dependent vesicle fusion by αS. The enhancement model involves monomeric αS acting as a cross-bridge to facilitate vesicle docking to the phospholipid bilayer. αS has a N-terminal membrane binding region that binds to the phospholipid bilayer and the C-terminal region that interacts with VAMP2 (Lou et al., 2010). The inhibition model involves oligomeric, multivalent αS interacting and clustering VAMP2, thus preventing it from engaging in SNARE complex formation and vesicle fusion.