Interaction of Influenza A Virus M1 Matrix Protein with Caspases

O. P. Zhirnov^1*, A. L. Ksenofontov¹, S. G. Kuzmina¹, and H. D. Klenk²

¹Ivanovski Virology Research Institute, Russian Academy of Medical Sciences, ul. Gamalei 16, Moscow, 123098 Russia; fax: (095) 190-3058; E-mail: olegzhirnov@hotmail.com

²Robert-Koch-Institüt, 13353 Berlin, Institüt für Virologie, Philipps-Universität, 35037 Marburg, Germany; fax: (49) 6421-2868962; E-mail: klenk@mailer.uni-marburg.de

^* To whom correspondence should be addressed.

Received October 3, 2001; Revision received February 1, 2002

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In this investigation, an ability of influenza A virus M1 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 M1 protein specifically bound caspase-8 and weakly bound caspase-7. Using a computer analysis of the N-terminal region of M1 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 M1 protein is involved in a caspase-8-mediated apoptosis pathway in influenza virus infected cells.

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KEY WORDS: influenza virus, apoptosis, matrix protein, caspases

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