Figure 2. . The progression of the autophagy process.
Autophagy initiates by sequestration of the lipid membrane from intracellular organelle like endoplasmic reticulum, Beclin-1 and atg9 could knock together a lipid collection machine to extend the lipid bilayer. In nucleation stage, atg12-atg5-atg16 complex is located near the phagophore surface to protected lipid bilayer from integration with other vesicles and also have the E3 conjugating system for LC3-II to progress LC3-I conversion, the lipid bilayer turns into phagosome and then another autophagy factor separates from the vesicle, with the exception of LC3-II. In the final stage, the autophagosome and lysosome could migrate on a microtubule and attach together via the SNARE protein and LC3-II marker.