Impact of Nitric Oxide (NO) on the ROS Metabolism of Peroxisomes.

Francisco J Corpas,Luis A Del Río,José M Palma

doi:10.3390/plants8020037

Abstract

Nitric oxide (NO) is a gaseous free radical endogenously generated in plant cells. Peroxisomes are cell organelles characterized by an active metabolism of reactive oxygen species (ROS) and are also one of the main cellular sites of NO production in higher plants. In this mini-review, an updated and comprehensive overview is presented of the evidence available demonstrating that plant peroxisomes have the capacity to generate NO, and how this molecule and its derived products, peroxynitrite (ONOO−) and S-nitrosoglutathione (GSNO), can modulate the ROS metabolism of peroxisomes, mainly throughout protein posttranslational modifications (PTMs), including S-nitrosation and tyrosine nitration. Several peroxisomal antioxidant enzymes, such as catalase (CAT), copper-zinc superoxide dismutase (CuZnSOD), and monodehydroascorbate reductase (MDAR), have been demonstrated to be targets of NO-mediated PTMs. Accordingly, plant peroxisomes can be considered as a good example of the interconnection existing between ROS and reactive nitrogen species (RNS), where NO exerts a regulatory function of ROS metabolism acting upstream of H2O2.

Highlights

Peroxisomes are organelles with an essential oxidative metabolism present in almost all categories of eukaryotic cells
Data accumulated during the last twenty years indicate that the hypothetical protein responsible for the Nitric oxide (NO) generation in peroxisomes has biochemical requirements similar to that of animal nitric oxide synthase (NOS), including substrate, cofactors and sensitivity to inhibitors [14,44], dependence on calcium and calmodulin [45], as well as dependence on the mechanism of the import system to peroxisomes through a peroxisomal targeting signal type 2 (PTS-2) [46]
Among the different peroxisomal proteins undergoing NO-derived posttranslational modifications (PTMs), in this article, we have focused on some of the key antioxidant enzymes of peroxisomes, including catalase (CAT), monodehydroascorbate reductase (MDAR), and copper-zinc superoxide dismutase (CuZnSOD)

Summary

Introduction

Peroxisomes are organelles with an essential oxidative metabolism present in almost all categories of eukaryotic cells. There is a common battery of enzymes that are present in all types of plant peroxisomes This includes a set of antioxidant systems whose functions are to keep under control the internal active metabolism of reactive oxygen species (ROS), mainly superoxide radicals (O2 ·− ) and hydrogen peroxide (H2 O2 ). These ROS are generated under physiological conditions by different pathways, such as purine catabolism, fatty acid β-oxidation, and photorespiration [7,8,9,10]. Peroxisomal NO metabolism is exacerbated under oxidative stress situations induced by abiotic conditions like salinity [17], and the heavy-metals cadmium [12,18], and lead [19]

Nitric Oxide Generation in Plant Peroxisomes

Peroxisomal Proteins

Conclusions and Future Perspectives