Figure 3: Roles of small GTPases in vesicular trafficking. Rab3D localizes to the lysosomal subset of the Trans Golgi Network (TGN) and is necessary for vesicular trafficking to the ruffled border. Rab7 localizes with late endosomes/lysosomes and the ruffled border. Rab7 and Rac1 are thought to facilitate the fusion of vesicles to the ruffled border. Rab13 localizes to small vesicles between the TGN and basolateral membrane and is thought to be involved in secretion.