%0 Journal Article
%T Reactive Oxygen Species-Mediated Control of Mitochondrial Biogenesis
%A Edgar D. Yoboue
%A Anne Devin
%J International Journal of Cell Biology
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/403870
%X Mitochondrial biogenesis is a complex process. It necessitates the contribution of both the nuclear and the mitochondrial genomes and therefore crosstalk between the nucleus and mitochondria. It is now well established that cellular mitochondrial content can vary according to a number of stimuli and physiological states in eukaryotes. The knowledge of the actors and signals regulating the mitochondrial biogenesis is thus of high importance. The cellular redox state has been considered for a long time as a key element in the regulation of various processes. In this paper, we report the involvement of the oxidative stress in the regulation of some actors of mitochondrial biogenesis. 1. Introduction Mitochondria are organelles that have critical functions in eukaryotic cells. Besides their well-known involvement in energy and intermediary metabolism (i.e., ATP synthesis, thermoregulation, heme biosynthesis), mitochondria also play a crucial role in both calcium homeostasis and apoptosis. Mitochondrial dysfunction has been associated with numerous pathologies including neurodegenerative diseases [1], diabetes [2], and aging [3, 4]. ATP synthesis by mitochondria is mostly generated through oxidative phosphorylation (OXPHOS) (Figures 1 and 2). Enzymatic complexes of the mitochondrial respiratory chain couple the oxidation of reducing agents such as NADH and FADH2 to proton extrusion toward the intermembrane space. Due to the low proton permeability of the inner mitochondrial membrane, this proton extrusion results in the establishment of an electrochemical potential difference in protons across this membrane. This proton electrochemical potential difference is, in turn, used for ATP synthesis by the F0F1-ATP synthase complexes. Figure 1: The mammalian oxidative phosphorylations (OXPHOS) system. Depicted are the four respiratory complexes (I¨CIV), electron carriers coenzyme Q and cytochrome c, the ATP synthase complex, the ADP/ATP carrier (ANC); and the phosphate carrier (PiC). Arrows at complexes I, III, and IV illustrate the proton pumping to the intermembrane space. Indicated are the number of complex subunits encoded by mitochondrial (mtDNA) and nuclear (nDNA) genomes. Figure 2: The Saccharomyces cerevisiae oxidative phosphorylations (OXPHOS) system. The main differences with the mammalian OXPHOS system are the absence of complex I that is substituted by external and internal NADH dehydrogenases, and the presence of D, L-lactate dehydrogenases, which transfer electrons directly to cytochrome c. Indicated are the number of protein subunits encoded by
%U http://www.hindawi.com/journals/ijcb/2012/403870/