Figure 3. Control of Mitochondrial Membrane Permeabilization (MMP) by Viral Proteins. A number of viral polypeptides modulate apoptosis, either by favoring or inhibiting MMP. This control can be exerted directly at mitochondria, or on upstream/downstream steps of the apoptotic cascade (please refer to the section “Viral Modulation of Mitochondrial Apoptosis” for further details). ADV, adenovirus; AEV, avian encephalomyelitis virus; ASFV, African swine fever virus; BLV, bovine leukemia virus; BCV, baculovirus; CMV, cytomegalovirus; EBNA, Epstein–Barr nuclear antigen; EBV, Epstein–Barr virus; Env, envelope glycoprotein complex; FMDV, foot-and-mouth disease virus; FPV, fowlpox virus; γHV-68, γ-herpesvirus 68; HBV, hepatitis B virus; HBx, HBV X protein; HCV, hepatitis C virus; HHV-8, human herpesvirus 8; HIV-1, human immunodeficiency virus 1; HPN, herpesvirus pan; HPO, herpesvirus papio; HPV, human papillomavirus; HTLV-1, human T lymphotropic virus 1; HVS, herpesvirus saimiri; IAV, influenza A virus; KSBcl-2, Kaposi sarcoma Bcl-2; M, matrix protein; MXV, myxoma virus; NS, non structural protein; ORF, open reading frame; P, phosphoprotein P; PPVO, parapoxvirus ORF virus; PTPC, permeability transition pore complex; PLV, poliovirus; RID, receptor internalization and degradation complex; SARS-CoV, severe acute respiratory syndrome coronavirus; VACV, vaccinia virus; vIAPs, viral inhibitor of apoptosis proteins; vICA, viral inhibitor of caspase-8 activation; vMAP, viral mitochondrial antiapoptotic protein; Vpr, viral protein R; VSV, vesicular stomatitis virus; WDSV, Walleye dermal sarcoma virus; WNV, West Nile virus.