SARS-CoV-2 ORF9b Antibody #60951

ORF9b (open reading frame 9b) is one of a variable number of so-called accessory proteins encoded by the genomes of coronaviruses such as SARS-CoV-2, the agent responsible for the COVID-19 global pandemic (1). Research studies have suggested that viral accessory proteins may not contribute directly to viral replication, but rather support viral infection by interfering with host defense mechanisms (2). For example, studies of SARS-CoV-1, the agent responsible for the 2003 SARS epidemic, revealed that SARS-CoV-1 ORF9b contributes to suppression of the host interferon (IFN) response, in part by interfering with key IFN effector proteins on the mitochondrial membrane (3). A conserved mechanism of action has since been described for ORF9b of SARS-CoV-2. Studies have shown that SARS-CoV-2 ORF9b localizes to the host mitochondrial membrane, and physically associates with TOM70, an adaptor protein within the MAVS/TRAF3/TRAF6/TOM70 protein complex on the mitochondrial membrane that promotes IFN signaling in response to viral infection (4,5).