Autophagic substrate that functions as host autophagy cargo receptor (Probable). Requires ATG8 protein expression to be recognized as an autophagic substrate (Probable). Activates ATG8CL-mediated selective autophagy, and contributes to defense against the fungal pathogen Phytophtora infestans (PubMed:26765567, PubMed:29932422). Interacts (via C-terminal AIM motif) with ATG8CL. The ATG8 interacting motif (AIM) is required for the interaction with ATG8CL (PubMed:26765567, PubMed:29932422). The AIM motif is required for JOKA2 function as host autophagy cargo receptor (PubMed:26765567, PubMed:29932422).