Fig. 1.

The autophagic process and its regulation. Here, presented are two major pathways that regulate autophagy triggering. The mTOR pathway inhibits autophagy in response to Class I PI3K and amino acids. The eIF-2α kinases are positive regulators of autophagy in response to starvation, ER stress and viral infection. Autophagy triggering is dependent on the Class III PI3K signalling and on two conjugation systems. First, a pre-autophagosome is formed and sequesters cytoplasmic material. Its completion leads to autophagosome formation that fuses with lysosome to form autolysosome where the sequestered material is degraded