Abstract
Frataxin is a mitochondrial protein which deficiency causes Friedreich’s ataxia, a cardio-neurodegenerative disease. The lack of frataxin induces the dysregulation of mitochondrial iron homeostasis and oxidative stress, which finally causes the neuronal death. The mechanism through which frataxin regulates the oxidative stress balance is rather complex and poorly understood. While the absence of human (Hfra) and yeast (Yfh1) frataxins turn out cells sensitive to oxidative stress, this does not occur when the frataxin gene is knocked-out in E. coli. To better understand the biological roles of Hfra and Yfh1 as endogenous antioxidants, we have studied their ability to inhibit the formation of reactive oxygen species (ROS) from Cu2+- and Fe3+-catalyzed degradation of ascorbic acid. Both proteins drastically reduce the formation of ROS, and during this process they are not oxidized. In addition, we have also demonstrated that merely the presence of Yfh1 or Hfra is enough to protect a highly oxidation-prone protein such as α-synuclein. This unspecific intervention (without a direct binding) suggests that frataxins could act as a shield to prevent the oxidation of a broad set of intracellular proteins, and reinforces that idea that frataxin can be used to prevent neurological pathologies linked to an enhanced oxidative stress.
Highlights
IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
We took as reactions model the Cu2+ - and Fe3+ -catalyzed ascorbic acid (AA) degradations
FRDA is a rare neurodegenerative disease caused by a deficiency in the expression levels of frataxin, a small mitochondrial protein considered as an iron-binding protein
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Friedreich’s ataxia (FRDA) is a neurodegenerative disease which prevalence strongly varies between different countries and even within the same country It is characterized by an unsteady posture, falling, and a progressive difficulty in walking due to an impaired ability to coordinate movements [2]. FRDA appears as a result of an abnormal expansion of the GAA trinucleotide repeat in the first intron of the nuclear FXN gene [3]. Healthy persons have roughly 6 to 36 repeats, whereas
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