Xenophagy-specific receptor required for autophagy-mediated intracellular bacteria degradation. Acts as an effector protein of galectin-sensed membrane damage that restricts the proliferation of infecting pathogens such as Salmonella typhimurium upon entry into the cytosol by targeting LGALS8-associated bacteria for autophagy (PubMed:22246324). Initially orchestrates bacteria targeting to autophagosomes and subsequently ensures pathogen degradation by regulating pathogen-containing autophagosome maturation (PubMed:23022382, PubMed:25771791). Bacteria targeting to autophagosomes relies on its interaction with MAP1LC3A, MAP1LC3B and/or GABARAPL2, whereas regulation of pathogen-containing autophagosome maturation requires the interaction with MAP3LC3C (PubMed:23022382, PubMed:25771791). May play a role in ruffle formation and actin cytoskeleton organization and seems to negatively regulate constitutive secretion (PubMed:17635994). Dimer (PubMed:23511477). Part of a complex consisting of CALCOCO2, TAX1BP1 and MYO6 (PubMed:17635994). Interacts with GEMIN4 (PubMed:12869526). Interacts with ATG8 family members MAP1LC3A, MAP1LC3B, GABARAP, GABARAPL1 and GABARAPL2 (PubMed:25771791). Interacts with ATG8 family member MAP1LC3C (PubMed:23022382). Interacts with LGALS8 (PubMed:22246324, PubMed:25771791, PubMed:23511477, PubMed:23386746). According to PubMed:7540613, localizes to nuclear dots. According to PubMed:9230084 and PubMed:12869526, it is not a nuclear dot-associated protein but localizes predominantly in the cytoplasm with a coarse-grained distribution preferentially close to the nucleus. Expressed in all tissues tested with highest expression in skeletal muscle and lowest in brain. Treatment with IFNB1/IFN-beta and IFNG/IFN-gamma show an increase in number and size of CALCOCO2-specific dots and partial redistribution to the cytoplasm (PubMed:7540613). IFNG/IFN-gamma increases gene expression only slightly and IFNB does not increase expression (PubMed:9230084). The MYO6-binding domain is required for autophagy-mediated degradation of infecting bacteria such as Salmonella typhimurium, but not for bacteria targeting to autophagosomes. The CLIR (LC3C-interacting region) motif is required for interaction with MAP1LC3C, but dispensable for CALCOCO2-mediated autophagosome maturation. The LIR-like motif is required for interaction with MAP1LC3A, MAP1LC3B and GABARAPL2, as well as for CALCOCO2-mediated autophagosome maturation. The LGALS8-binding domain is essential for the recruitment to cytosol-exposed infecting bacteria. Belongs to the CALCOCO family.