Ubiquitin-like modifier involved in autophagosomes formation (Probable). May mediate the delivery of the autophagosomes to the vacuole via the microtubule cytoskeleton (Probable). ATG8CL-mediated selective autophagy contributes to defense against the fungal pathogen Phytophtora infestans (PubMed:26765567, PubMed:29932422). Interacts with ATG4 (By similarity). Interacts with the Phytophtora infestans effector PexRD54 (PubMed:26765567, PubMed:27458016). Interacts with JOKA2 (PubMed:26765567, PubMed:29932422). The C-terminal 2 residues are removed by ATG4 to expose Gly-117 at the C-terminus (By similarity). The C-terminal Gly is then amidated with phosphatidylethanolamine by an activating system similar to that for ubiquitin (Probable). The phosphatidylethanolamine amidated glycine is required for autophagosome formation (PubMed:26765567). Belongs to the ATG8 family.