Gene Accession

P0DTC3

Gene Alias

ORF3a protein (ORF3a) (Accessory protein 3a) (Protein 3a) (Protein U274) (Protein X1)

Background

FUNCTION: Plays a role in viral egress via lysosomal trafficking (PubMed:33157038, PubMed:33422265). Forms homotetrameric ion channels (viroporins) 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 autolysosome formation by binding and sequestering the host component VPS39 for homotypic fusion and protein sorting (HOPS) on late endosomes (PubMed:33422265). This prevents fusion of autophagosomes with lysosomes, disrupting autophagy and facilitating virus egress (PubMed:33422265). Induces host RETREG1/FAM134B-dependent reticulophagy by interacting with host HMGB1 and enhancing the association between HMGB1 and host BECN1 (PubMed:35239449). This induces endoplasmic reticulum stress and inflammatory responses and facilitates viral infection (PubMed:35239449). {ECO:0000269|PubMed:33157038, ECO:0000269|PubMed:33422265, ECO:0000269|PubMed:34158638, ECO:0000269|PubMed:35239449}.