IFN-induced antiviral protein which disrupts intracellular cholesterol homeostasis. Inhibits the entry of viruses to the host cell cytoplasm by preventing viral fusion with cholesterol depleted endosomes. May inactivate new enveloped viruses which buds out of the infected cell, by letting them go out with a cholesterol depleted membrane. Active against multiple viruses. Plays a critical role in the structural stability and function of vacuolar ATPase (v-ATPase). Establishes physical contact with the v-ATPase of endosomes which is critical for proper clathrin localization and is also required for the function of the v-ATPase to lower the pH in phagocytic endosomes thus establishing an antiviral state. Interacts with ATP6V0B (By similarity). Interacts with CD81 (By similarity). Interacts with SPP1; the interaction reduces OPN expression (By similarity). Interacts with BRI3 (By similarity). Co-localizes with BRI3 isoform 1 at the perinuclear region. By interferon beta. Polyubiquitinated with both 'Lys-48' and 'Lys-63' linkages. Ubiquitination negatively regulates antiviral activity. Lys-24 is the most prevalent ubiquitination site. Phosphorylation at Tyr-20 is required for endosomal and lysosomal location. Belongs to the CD225/Dispanin family.