Non-canonical roles of ATG8 for TFEB activation

Autophagy is an evolutionally conserved cytoplasmic degradation pathway in which the double membrane structure, autophagosome sequesters cytoplasmic material and delivers them to lysosomes for degradation. Many autophagy related (ATG) proteins participate in the regulation of the several steps of autophagic process. Among ATGs, ubiquitin-like protein, ATG8 plays a pivotal role in autophagy. ATG8 is directly conjugated on lipid in autophagosome membrane upon induction of autophagy thus providing a good marker to monitor and analyze autophagy process. However, recent discoveries suggest that ATG8 has autophagy independent non-canonical functions and ATG8 positive structures are not always autophagosomes. This review briefly overviews canonical and non-canonical roles of ATG8 and introduce novel function of ATG8 to activate Transcriptional Factor EB(TFEB), a master transcription factor of autophagy and lysosome function during lysosomal damage.