Interferon-induced GTP-binding protein Mx2 (MX2)

Interferon-induced GTP-binding protein Mx2 (MX2) is a large dynamin-like GTPase induced by type I interferons (IFN-α/β), present in both nuclear and cytoplasmic forms, and primarily acts as a restriction factor against HIV-1 and some other viruses. MX2 binds the viral capsid after reverse transcription but before nuclear import and proviral integration, preventing successful infection by blocking nuclear trafficking of the viral genome, particularly in HIV-1; N-terminal domains and interactions with nuclear pore components are crucial for this activity. Its antiviral spectrum includes several herpesviruses (where GTPase function is required for activity) and possible inhibitory roles in hepatitis B virus. While MX2 is not itself a direct therapeutic target, it represents a key node in the innate immune response, and its upregulation by interferons underlies much of its biological significance.

Other names

MX dynamin-like GTPase 2MXBInterferon-regulated resistance GTP-binding protein MXBMyxovirus resistance protein 2p78-related proteinSecond interferon-induced protein p78interferon-induced GTP-binding protein Mx2interferon-regulated resistance GTP-binding protein MXB

Not directly targeted by drugs, but mechanism relates to enzyme-mediated hydrolysis of GTP and oligomerization to restrict viral nuclear import. The effect of interferon, an established therapeutic, is to induce MX2 expression.