CALCOCO1 (calcium binding and coiled-coil domain 1) is a soluble selective autophagy receptor that functions as a key regulator of reticulophagy and Golgiphagy. As a reticulophagy receptor, CALCOCO1 targets misfolded endoplasmic reticulum (ER) proteins for lysosomal degradation, functioning in parallel with RTN3L and ATL3 to maintain ER proteostasis 1. CALCOCO1 works by recruiting autophagy machinery to damaged ER subdomains through interaction with autophagy-related proteins and LC3 2. Additionally, CALCOCO1 serves as a Golgiphagy receptor, binding to Golgi-resident palmitoyltransferases ZDHHC17 and ZDHHC13 via a specific zDHHC-AR-binding motif to mediate Golgi autophagy during nutrient deprivation 3. Under ER stress, CALCOCO1 mRNA stability is enhanced through m6A methylation by METTL3/METTL14, which promotes ER-phagy machinery formation and paclitaxel sensitivity in breast cancer cells 4. CALCOCO1 is also involved in prion-induced ER stress responses, where it interacts with the stress regulator ARL6IP5 to facilitate reticulophagy and reduce misfolded prion protein burden 5. These functions establish CALCOCO1 as a critical component linking ER stress responses with selective autophagy for cellular homeostasis maintenance.