Fig. 6.

Potential role of Atg9 in autophagosome maturation. Schematic showing the autophagic progression from initiation at the PAS, membrane elongation to form the phagophore, membrane closure to encapsulate a mitochondrion in the autophagosome which then fuses with a multivesicular endosome to form an amphisome and finally fusion with a lysosome to produce an autolysosome. (A) Atg9 potentially facilitates the formation of intraluminal vesicle at the late endosome to form a multivesicular endosome prior to fusion with an autophagosome. (B) Atg9 also potentially facilitates intraluminal vesicle formation in amphisomes and autolysosome. PAS, phagophore assembly site; Atg, autophagy related gene.