Skip to main content
. 2022 Mar 23;14(7):1637. doi: 10.3390/cancers14071637

Figure 2.

Figure 2

(A): Autophagy signals mostly converge at the level of mTOR protein complexes, which are regulated by AMPK. mTORC1 may limit autophagy by inactivating ULK1/2; (B): The class III phosphatidylinositol 3-kinase (PI3K) complex mediates the membrane nucleation stage and the initial building of the phagophore; (C): The elongation and closure stage depends on two ubiquitin-like conjugation systems. In the first system, ATG12 links to ATG5, mediated by ATG7 and ATG10. Next, ATG16L1 and ATG12-5 are recruited which results in the formation of a larger protein complex. Consecutively, lipid molecules are conjugated by ATG12-5-16L1 oligomers, serving as E3 ligases. Lipid-conjugated ATG8 is a prerequisite for the elongation and closure stage; (D): After autophagosomes fuse with late endosomes or lysosomes, they can exert their full lytic capacity; (E): Following the integration of the outer membranes of autophagosomes, cell cargo located in the inner membrane is degraded by lysosomal hydrolases. Figure adapted after Kocaturk et al. [29].