The murine gammaherpesvirus-68 M11 protein inhibits Fas- and TNF-induced apoptosis.

The murine gammaherpesvirus-68 (MHV-68) M11 gene encodes a protein predicted to have limited homology to the bcl-2 family of proteins. Unlike most of the other viral bcl-2 homologues, which have both BH1 and BH2 domains conserved with respect to bcl-2, the M11 protein has a BH1 domain, but apparently lacks a BH2 domain. Transfection of HeLa cells with an epitope-tagged MHV-68 M11 construct showed that the protein is predominantly located in the cytoplasm of cells. In HeLa cells, M11 inhibited apoptosis induced by anti-Fas antibody and by TNF-alpha. Thus, despite its limited conservation with respect to other bcl-2 family members, the MHV-68 M11 protein is a potent inhibitor of apoptosis.