Functions as antiviral protein and contributes to the defense against retroviral infections (PubMed:17156811, PubMed:32282853). Acts as a capsid-specific restriction factor with the help of TRIM5 and prevents infection from non-host-adapted retroviruses (PubMed:32282853). During influenza A virus infection, promotes programmed cell death by targeting ZBP1 for ‘Lys-63’-linked polyubiquitination (PubMed:35065966). In turn, promotes ZBP1 recruitment of RIPK3 to mediate virus-induced programmed necrosis (PubMed:35065966). Negatively regulates the function of mitochondria by enhancing mitochondrial depolarization leading to cytochrome c release and mitochondria-dependent apoptosis (PubMed:31956709). Promotes also the formation of multinucleated giant cells by means of cell fusion and phagocytosis in epithelial cells (PubMed:31487507).
