Mx proteins: mediators of innate resistance to RNA viruses

Mx proteins are interferon-induced members of the dynamin superfamily of large guanosine triphosphatases. These proteins have attracted attention because some display antiviral activity against pathogenic RNA viruses, for example against members of the orthomyxovirus (influenzavirus) family or the bunyavirus family. Transfected cells and transgenic mice expressing Mr proteins are highly resistant to Mx-sensitive viruses, demonstrating that Mr proteins are powerful antiviral agents. In humans, synthesis of MxA is observed during self-limiting viral infections and may thus promote recovery from disease.