Interaction of influenza A virus M1 matrix protein with caspases

In this investigation, an ability of influenza A virus M I matrix protein to bind intracellular caspases, the key enzymes of cell apoptosis, has been examined. Protein-protein binding on polystyrene plates and polyvinyl pyrrolidone membrane was employed for this purpose. Under a comparative study of caspases-3, -6, -7, -8 influenza virus M I protein specifically bound caspase-8 and weakly bound caspase-7. Using a computer analysis of the N-terminal region of M I protein, a site similar to the anti-caspase site of baculovirus p35 protein, which inhibits caspases and displays antiapoptotic activity, was identified. These results are in good agreement with the supposition that influenza virus M I protein involved in a caspase-8-mediated apoptosis pathway in influenza virus infected cells.