Forms homotetrameric potassium sensitive ion channels (viroporin) and may modulate virus release. Up-regulates expression of fibrinogen subunits FGA, FGB and FGG in host lung epithelial cells. Induces apoptosis in cell culture. Down-regulates the type 1 interferon receptor by inducing serine phosphorylation within the IFN alpha-receptor subunit 1 (IFNAR1) degradation motif and increasing IFNAR1 ubiquitination (By similarity). Homotetramer composed of two homodimers linked non covalently. Interacts with M, S and E proteins. Also interacts with the accessory protein 7a (By similarity). The cell surface expressed protein can undergo endocytosis. The protein is secreted in association with membranous structures (By similarity). The second or the third transmembrane region are responsible for Golgi localization. Exists in both O-glycosylated and non-glycosylated forms. The glycosylated form is associated with the virion (By similarity). Bat coronavirus 279/2005 is highly similar to SARS-CoV (SARS-like).