Accessory protein involved in autophagy. Acts as scaffold protein of the ATG1-ATG13 complex for faithful delivery of autophagic vesicles to the vacuole. Involved in the stress-induced phosphorylation of ATG1A for turnover of ATG1-ATG13 complex and proper ATG1-ATG13 complex assembly or activity. Required for selective mitophagy. Required for senescence-induced breakdown of mitochondria-resident proteins and mitochondrial vesicles. Seems not essential for ATG8-mediated autophagy. Homodimer. Interacts with ATG8E, ATG13A and ATG101. Binds to ATG8E on autophagic vesicles. Mutant plants are hypersensitive to nitrogen or carbon starvation and show early senescence. Belongs to the ATG11 family.