Fig. 5. PI 3-kinases in membrane trafficking. The figure summarizes the involvement of PI 3-kinases in trafficking pathways discussed in this review. PI 3-kinases (catalytic subunits) are indicated in green. ER, endoplasmic reticulum; EE, early endosome; G4V, GLUT4-containing vesicle; LE, late endosome; MVE, multivesicular endosome; PAS, pre-autophagosomal structure; RE, recycling endosome; SG, secretory granule.