Following to his discovery on a new protein—ORF-3a in SARS-CoV two years ago, Prof. Sun Bing, Principal Investigator in Institut Pasteur of Shanghai and his team further discovered the function of 3a protein as an ion channel regulating SARS-CoV release. The results are published at the recent Proceedings of the National Academy of Sciences, USA (PNAS). 　　

　　SARS-CoV has a large single-positive-strand RNA genome that contains 14 ORFS. Some of these ORFS encode viral structural proteins, such as spike protein, membrane protein, small envelope protein and nucleocapsid protein. These proteins play very important roles in viral infection and replication. However, the pathogenesis of SARS-CoV is still not clear. So research on functions of viral proteins has important significance to understand pathogenesis and develop anti-virals. 　　

　　After the study on the function of 3a protein in nearly 2 years, Prof. Sun’s team found out that 3a forms a potassium-sensitive ion channel and regulates virus release. Researchers are trying to illuminate the mechanisms of 3a protein in regulating virus release and in pathogenesis of SARS-CoV infection, and to explore the possibility of 3a as a target for drugs against SARS-CoV. In the meantime, a platform for studying ion channels will be applied for other viruses. 　　

　　This work of Prof. Sun Bing’s team has involved the Institute of Biochemistry and Cell Biology; the Max Planck Guest Laboratory; the Institute of Neuroscience, Shanghai Institute of Biological Science, Chinese Academy of Science; the Department of Microbiology of the University of Hong Kong and Queen Mary Hospital.