Plays a role in viral egress via lysosomal trafficking (PubMed:33157038, PubMed:33422265). Forms homotetrameric ion channels (viroporin) localized at endosomes and lysosomes, that may induce deacidification of lysosomes, allowing safe egress of virions via lysosomal trafficking (PubMed:33157038, PubMed:33422265,PubMed:34158638). Also blocks autolysosomes formation by binding and sequestering the host component VPS39 for homotypic fusion and protein sorting (HOPS) on late endosomes. This prevents fusion of autophagosomes with lysosomes, disrupting autophagy and facilitating virus egress (PubMed:33422265). Homodimer (PubMed:34158638), a subset forms homotetramer of two homodimers linked non covalently (PubMed:34158638, PubMed:34158638). Interacts with M, S and E proteins. Also interacts with the accessory protein 7a (By similarity). Interacts with host VPS39, sequestering it on late endosomes (PubMed:33422265). The cell surface expressed protein can undergo endocytosis. The protein is secreted in association with membranous structures. 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. Variant Omicron/BA.1 and BA.2 belong to a lineage first isolated in South Africa (November 2021).