Structural and functional insights into nitrosoglutathione reductase from Chlamydomonas reinhardtii - Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes Accéder directement au contenu
Article Dans Une Revue Redox Biology Année : 2021

Structural and functional insights into nitrosoglutathione reductase from Chlamydomonas reinhardtii

Résumé

Protein S-nitrosylation plays a fundamental role in cell signaling and nitrosoglutathione (GSNO) is considered as the main nitrosylating signaling molecule. Enzymatic systems controlling GSNO homeostasis are thus crucial to indirectly control the formation of protein S-nitrosothiols. GSNO reductase (GSNOR) is the key enzyme controlling GSNO levels by catalyzing its degradation in the presence of NADH. Here, we found that protein extracts from the microalga Chlamydomonas reinhardtii catabolize GSNO via two enzymatic systems having specific reliance on NADPH or NADH and different biochemical features. Scoring the Chlamydomonas genome for orthologs of known plant GSNORs, we found two genes encoding for putative and almost identical GSNOR isoenzymes. One of the two, here named CrGSNOR1, was heterologously expressed and purified. Its kinetic properties were determined and the three-dimensional structures of the apo-, NAD +-and NAD + /GSNO-forms were solved. These analyses revealed that CrGSNOR1 has a strict specificity towards GSNO and NADH, and a conserved folding with respect to other plant GSNORs. The catalytic zinc ion, however, showed an unexpected variability of the coordination environment. Furthermore, we evaluated the catalytic response of CrGSNOR1 to thermal denaturation, thiol-modifying agents and oxidative modifications as well as the reactivity and position of accessible cysteines. Despite being a cysteine-rich protein, CrGSNOR1 contains only two solvent-exposed/ reactive cysteines. Oxidizing and nitrosylating treatments have null or limited effects on CrGSNOR1 activity and folding, highlighting a certain resistance of the algal enzyme to redox modifications. The molecular mechanisms and structural features underlying the response to thiol-based modifications are discussed.
Fichier principal
Vignette du fichier
1-s2.0-S2213231720310119-main.pdf (11.68 Mo) Télécharger le fichier
Origine : Publication financée par une institution

Dates et versions

hal-03268712 , version 1 (23-06-2021)

Identifiants

Citer

Andrea Tagliani, Jacopo Rossi, Christophe H Marchand, Marcello de Mia, Daniele Tedesco, et al.. Structural and functional insights into nitrosoglutathione reductase from Chlamydomonas reinhardtii. Redox Biology, 2021, 38, pp.101806. ⟨10.1016/j.redox.2020.101806⟩. ⟨hal-03268712⟩
65 Consultations
81 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More