Papain-like 2 protease of coronavirus and innate immune response

the few decades, certain coronaviruses have become threat to humans. Coronaviruses such as severe acute respiratory syndrome-related coronavirus (SARS-CoV) and Middle East respiratory syndrome-related coronavirus (MERS-CoV) have caused lethal outbreaks in 2003 and 2012, respectively. In 2019, severe infectious coronavirus outbreak with unusual pneumonia was reported in Wuhan, China, which later became pandemic. Due to the similarity of coronavirus disease 2019 (COVID-19) to SARS-CoV, the virus was termed as SARS-CoV-2. Although viral proteases such as papain-like 2 protease (PL2 Pro ) are essential for virulence of SARS-CoV, limited information is available on the role of protease in viral pathogenesis. This article highlights the significance of ubiquitination in signal transduction for innate immune responses and the im-portance of deubiquitinase activity of PL2 Pro in inhibiting host antiviral activities.