Oxidation of Са2+-Binding Domain of NADPH Oxidase 5 (NOX5): Toward Understanding the Mechanism of Inactivation of NOX5 by ROS

Irina Yu Petrushanko (1) , Vladimir A Lobachev (1) , Alexey A Kononikhin (2) , Alexander Makarov (1) , François O Devred (3) , Hervé Kovacic (3) , Aslan A Kubatiev (4) , Philipp A Tsvetkov (4, 3)

1 ISTC - Engelhardt Institute of Molecular Biology
2 MIPT - Moscow Institute of Physics and Technology [Moscow]
3 CRO2 - Centre de Recherches en Oncologie biologique et Oncopharmacologie
4 Institute of General Pathology and Pathophysiology

NOX5 protein, one of the most active generators of reactive oxygen species (ROS), plays an important role in many processes, including regulation of cell growth, death and differentiation. Because of its central role in ROS generation, it needs to be tightly regulated to guarantee cellular homeostasis. Contrary to other members of NADPH-oxidases family, NOX5 has its own regulatory calcium-binding domain and thus could be activated directly by calcium ions. While several mechanisms of activation have been described, very little is known about the mechanisms that could prevent the overproduction of ROS by NOX5. In the present study using calorimetric methods and circular dichroism we found that oxidation of cysteine and methionine residues of NOX5 decreases binding of Ca2+ ions and perturbs both secondary and tertiary structure of protein. Our data strongly suggest that oxidation of calcium-binding domain of NOX5 could be implicated in its inactivation, serving as a possible defense mechanism against oxidative stress.

Mots clés: Oxidation; Reactive oxygen species; Methionine; Hydrogen peroxide; Peroxides; Isothermal titration calorimetry; Protein structure; Stoichiometry

Domaines: Biochimie [q-bio.BM]

Irina Yu Petrushanko, Vladimir A Lobachev, Alexey A Kononikhin, Alexander Makarov, François O Devred, et al.. Oxidation of Са2+-Binding Domain of NADPH Oxidase 5 (NOX5): Toward Understanding the Mechanism of Inactivation of NOX5 by ROS. PLoS ONE, 2016, 11 (7), pp.e0158726. ⟨10.1371/journal.pone.0158726⟩. ⟨hal-01744694⟩