Mitochondrial localization of viral proteins as a means to subvert host defense

Viruses have developed a battery of distinct strategies to overcome the very sophisticated defense mechanisms of the infected host. Throughout the process of pathogen-host co-evolution, viruses have therefore acquired the capability to prevent host cell apoptosis because elimination of infected cells via apoptosis is one of the most ancestral defense mechanism against infection. Conversely, induction of apoptosis may favor viral dissemination as a result of the dismantlement of the infected cells. Mitochondria have been long recognized for their key role in the modulation of apoptosis but more recently, mitochondria have been shown to serve as a crucial platform for innate immune signaling as illustrated by the identification of MAVS. Thus, it is therefore not surprising that this organelle represents a recurrent target for viruses, aiming to manipulate the fate of the infected host cell or to inhibit innate immune response. In this review, we highlight the viral proteins that are specifically targeted to the mitochondria to subvert host defense. This article is part of a Special Issue entitled Mitochondria: the deadly organelle. (C) 2010 Elsevier B.V. All rights reserved.