Inhibition of VSV and EMCV replication by the interferon-induced GTPase, mGBP-2: differential requirement for wild-type GTP binding domain.

Interferons (IFNs) exert their anti-viral activities through the induction of anti-viral proteins. One member of the guanylate binding protein (GBP) family of IFN-induced GTPases, hGBP-1, has previously been shown to contribute to the antiviral activities of IFNs. Murine GBP-2 inhibited the replication of both vesicular stomatitis virus (VSV) and encephalomyocarditis virus (EMCV). A wild type GTP binding motif was not required for VSV inhibition but was required for inhibition of EMCV. This is the first demonstration of the role of enzymatic activity in the antiviral activities of GBPs and these findings suggest different mechanisms of inhibition for the two viruses.