Beyond Autophagy: The Expanding Roles of ATG8 Proteins

The ATG8 family proteins are critical players in autophagy, a cytoprotective process that mediates degradation of cytosolic cargo. During autophagy, ATG8s conjugate to autophagosome membranes to facilitate cargo recruitment, autophagosome biogenesis, transport, and fusion with lysosomes, for cargo degradation. In addition to these canonical functions, recent reports demonstrate that ATG8s are also delivered to single-membrane organelles, which leads to highly divergent degradative or secretory fates, vesicle maturation, and cargo specification. The association of ATG8s with different vesicles involves complex regulatory mechanisms still to be fully elucidated. Whether individual ATG8 family members play unique canonical or non-canonical roles, also remains unclear. This review summarizes the many open molecular questions regarding ATG8s that are only beginning to be unraveled.

Automated summary

The ATG8 family proteins are key players in autophagy, participating in cargo recruitment, biogenesis, transport, and fusion with lysosomes. Recent studies have shown their involvement in diverse processes such as vesicle maturation and cargo specification, with complex regulatory mechanisms that are still not fully understood. Individual roles of different ATG8 family members in canonical or non-canonical pathways remain unclear. This review highlights the molecular questions surrounding ATG8s that are only beginning to be explored.