Also known as Autophagy protein 13 (Meiotically up-regulated gene 78 protein). Activates the atg1 kinase in a nutritional condition dependent manner through the TOR pathway, leading to autophagy. Also involved in cytoplasm to vacuole transport (Cvt) and more specifically in Cvt vesicle formation. Seems to play a role in the switching machinery regulating the conversion between the Cvt pathway and autophagy. Autophagy functions to supply nitrogen and is activated when cells cannot access exogenous nitrogen, thus ensuring that they can adapt and subsequently propagate. Finally, atg13 is also required for glycogen storage during stationary phase and has a role in meiosis and sporulation.
Stabilizes the ATG5-ATG12 conjugate which is necessary for autophagy. The ATG5-ATG12/ATG16 complex is required for efficient promotion of ATG8-conjugation to phosphatidylethanolamine and ATG8 localization to the pre-autophagosomal structure (PAS). Recruits also ATG3 to the PAS. Involved in endoplasmic reticulum-specific autophagic process and is essential for the survival of cells subjected to severe ER stress ().
Involved in cytoplasm to vacuole transport (Cvt) and autophagic vesicle formation. Autophagy is essential for maintenance of amino acid levels and protein synthesis under nitrogen starvation. Required for selective autophagic degradation of the nucleus (nucleophagy). Also required for mitophagy, which eliminates defective or superfluous mitochondria in order to fulfill cellular energy requirements and prevent excess ROS production. Conjugation with ATG12, through a ubiquitin-like conjugating system involving ATG7 as an E1-like activating enzyme and ATG10 as an E2-like conjugating enzyme, is essential for its function. The ATG12-ATG5 conjugate acts as an E3-like enzyme which is required for lipidation of ATG8 and ATG8 association to the vesicle membranes ().