%0 Journal Article
%T Viruses as Modulators of Mitochondrial Functions
%A Sanjeev K. Anand
%A Suresh K. Tikoo
%J Advances in Virology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/738794
%X Mitochondria are multifunctional organelles with diverse roles including energy production and distribution, apoptosis, eliciting host immune response, and causing diseases and aging. Mitochondria-mediated immune responses might be an evolutionary adaptation by which mitochondria might have prevented the entry of invading microorganisms thus establishing them as an integral part of the cell. This makes them a target for all the invading pathogens including viruses. Viruses either induce or inhibit various mitochondrial processes in a highly specific manner so that they can replicate and produce progeny. Some viruses encode the Bcl2 homologues to counter the proapoptotic functions of the cellular and mitochondrial proteins. Others modulate the permeability transition pore and either prevent or induce the release of the apoptotic proteins from the mitochondria. Viruses like Herpes simplex virus 1 deplete the host mitochondrial DNA and some, like human immunodeficiency virus, hijack the host mitochondrial proteins to function fully inside the host cell. All these processes involve the participation of cellular proteins, mitochondrial proteins, and virus specific proteins. This review will summarize the strategies employed by viruses to utilize cellular mitochondria for successful multiplication and production of progeny virus. 1. Introduction 1.1. Mitochondria Mitochondria are cellular organelles found in the cytoplasm of almost all eukaryotic cells. One of their important functions is to produce and provide energy to the cell in the form of ATP, which help in proper maintenance of the cellular processes, thus making them indispensable for the cell. Besides acting as a powerhouse for the cell, they act as a common platform for the execution of a variety of cellular functions in normal or microorganism infected cells. Mitochondria have been implicated in aging [1, 2], apoptosis [3¨C7], the regulation of cell metabolism [4, 8], cell-cycle control [9¨C11], development of the cell [12¨C14], antiviral responses [15], signal transduction [16], and diseases [17¨C20]. Although all mitochondria have the same architecture, they vary greatly in shape and size. The mitochondria are composed of outer mitochondrial membrane, inner mitochondrial membrane, intermembrane space (space between outer and inner membrane), and matrix (space within inner mitochondrial membrane). The outer membrane is a smooth phospholipid bilayer, with different types of proteins imbedded in it [21]. The most important of them are the porins, which freely allow the transport (export and import) of
%U http://www.hindawi.com/journals/av/2013/738794/