Figure 2.

Schematic diagram depicting trafficking and fusion of the autophagosome to the vacuole and degradation of the autophagic body inside the vacuole in yeast. PI3P and Atg8 anchored in the outer membrane of the autophagosome are involved in autophagosome trafficking and bind autophagosome with FYVE and coiled-coil domain-containing protein 1 (FYCO1). The complex autophagosome-FYCO1-Ypt7 moves along microtubules in the direction of the plus end by the binding of Ypt7 to kinesin motor proteins. Proteins Vam3, Vam7, Vti1, Ykt6, Ypt7, and complexes Ccz1-Mon1 and HOPS are involved in the fusion of the autophagosome and vacuole. The newly formed autophagic body inside the vacuole is rapidly degraded by lytic enzymes. Proteins involved in the degradation of the autophagic body are proteinase A (Pep4), proteinase B (Prb1), and putative lipase Atg15. Other proteins that are probably involved in the degradation of the autophagic body are Atg22, Atg42, Prc, and Ybr139. It is suggested that Atg22, Avt3, and Avt4 are involved in metabolite efflux from the vacuole to the cytoplasm. Question marks indicate the hypothetical involvement of proteins in the degradation of the autophagic body and metabolite efflux from the vacuole to the cytoplasm.