Autophagosome

[3] The initial step of autophagosome formation of an omegasome on the endoplasmic reticulum, followed by of elongation of structures called phagophores.

LC3 is commonly used as a marker of autophagosomes in immunocytochemistry, because it is the essential part of the vesicle and stays associated until the last moment before its fusion.

[7] Nonetheless, these structures contain endocytic markers even small lysosomal proteins such as cathepsin D. The process is similar in yeast, however the gene names differ.

Mature yeast autophagosomes fuse directly with vacuoles or lysosomes and do not form amphisomes as in mammals.

[8] In neurons, autophagosomes are generated at the neurite tip and mature (acidify) as they travel towards the cell body along the axon.

[9] This axonal transport is disrupted if huntingtin or its interacting partner HAP1, which colocalize with autophagosomes in neurons, are depleted.