HAO, Jingfang; PÉTRIACQ, Pierre; DE BONT, Linda; HODGES, Michael; GAKIÈRE, Bertrand

doi:10.1016/j.plantsci.2018.03.016

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HAO, Jingfang
Institut des Sciences des Plantes de Paris-Saclay [IPS2 (UMR_9213 / UMR_1403)]

PÉTRIACQ, Pierre
Biologie du fruit et pathologie [BFP]
Institut des Sciences des Plantes de Paris-Saclay [IPS2 (UMR_9213 / UMR_1403)]

DE BONT, Linda
Institut des Sciences des Plantes de Paris-Saclay [IPS2 (UMR_9213 / UMR_1403)]

Langue

Article de revue

Ce document a été publié dans

Plant Science. 2018, vol. 271, p. 133-142

Elsevier

Résumé en anglais

The flavoprotein l-aspartate oxidase (LASPO) is the first enzyme of the de novo biosynthetic pathway of NAD+ in plants. Although LASPO is considered pivotal to maintain NAD+ homeostasis, it has not been hitherto characterized in plants. Here, the cDNA encoding the LASPO from the model plant Arabidopsis thaliana (AtLASPO, At5g14760) has been cloned and expressed in Escherichia coli for subsequent enzyme characterization. The purified AtLASPO enzyme displayed a Km of 0.79 mM for l-aspartate and a kcat of 0.25 s−1. We could further detect an l-aspartate: fumarate oxidoreductase activity of the recombinant plant enzyme. In addition, results indicated that NADP+ but not NAD+, and even more strongly NADH, inhibited AtLASPO at physiological concentrations by competing with the flavin for binding to the apoprotein. LASPO optimal pH and temperature, as well as plastidial pyridine nucleotide concentrations may contribute to an increased NAD+ production in planta. Moreover, in Arabidopsis thaliana AtLASPO gene expression exhibited a clear correlation between LASPO activity and NAD+ levels, thus demonstrating that plant LASPO catalyzes a key metabolic step of NAD+ synthesis.< Réduire

Mots clés

Regulation

Mots clés en anglais

Arabidopsis thaliana

Competitive inhibition

NAD(+) biosynthesis

l-aspartate oxidase

DOI

http://dx.doi.org/10.1016/j.plantsci.2018.03.016

Project ANR

Saclay Plant Sciences - ANR-10-LABX-0040
Idex Paris-Saclay - ANR-11-IDEX-0003

Origine

Importé de hal

Unités de recherche

Biologie du Fruit & Pathologie (BFP) - UMR 1332