Roles of Autophagy Induced by Natural Compounds in Prostate Cancer

Figure 1

Schematic representation of autophagy. The process begins with the nucleation of the phagophore, followed by its elongation and expansion and its closure to form the double-membrane autophagosome. The autophagosome maturates first through fusion with endosome, producing an amphisome, and then with lysosome to form the final autolysosome, where the inner membrane and the sequestered content are degraded by the lysosomal hydrolases. Finally, the resulting macromolecules are returned to cytoplasm by permeases for reuse. In the figure, the core molecular machinery of autophagy is also illustrated, including the ULK complex that is required for autophagy induction, the PI3KCIII complex and the PI3P interacting proteins, such as WIPIs and DCFP1, which contribute to the phagophore formation and elongation. Also the LC3-II and Atg12-Atg5-Atg16L complexes take part to the elongation step. The Atg12-Atg5-Atg16L complex resides on the outer membrane of the phagophore and dissociates from the completed autophagosome. The LC3-II complex is present on both sides of the phagophore and autophagosome, but it is released by Atg4-mediated deconjugation from the outer membrane after autophagosome maturation.