Journal Article

Post-transcriptional regulation of nitrate reductase by light is abolished by an N-terminal deletion

Caboche, Michel, M, Unité de recherche Nutrition Azotée des Plantes (URNAP) ; Institut National de la Recherche Agronomique (INRA), Vincentz, M, Boutin, J.P, Laboratoire de biologie cellulaire et moléculaire ; Institut National de la Recherche Agronomique (INRA), Nussaume, Laurent, Meyer, Christian, C

1995

Overview

Higher plant nitrate reductases (NRs) carry an N-terminal domain whose sequence is not conserved in NRs from other organisms. A gene composed of a full-length tobacco NR cDNA with an internal deletion of 168 bp in the 5' end fused to the cauliflower mosaic virus 35S promoter and appropriate termination signals was constructed and designated as delta NR. An NR-deficient mutant of Nicotiana plumbaginifolia was transformed with this delta NR gene. In transgenic plants expressing this construct, NR activity was restored and normal growth resulted. Apart from a higher thermosensitivity, no appreciable modification of the kinetic parameters of the enzyme was detectable. The post-transcriptional regulation of NR by light was abolished in delta NR transformants. Consequently, deregulated production of glutamine and asparagine was detected in delta NR transformants. The absence of in vitro delta NR activity modulation by ATP suggests the impairment of delta NR phosphorylation and thereby suppression of delta NR post-translational regulation. These data imply that post-transcriptional control of NR expression is important for the flow of the nitrate assimilatory pathway

• Publisher: American Society of Plant Biologists (ASPB),CCSD,American Society of Plant Physiologists
• Subject: ACTIVIDAD ENZIMATICA / ACTIVITE ENZYMATIQUE / Adenosine Triphosphate / Adenosine Triphosphate - pharmacology / ADN / ADN RECOMBINADO / ADN RECOMBINE / Amino Acid Sequence / Amino acids / analysis / ARN MENSAJERO / ARN MESSAGER / Asparagine / Asparagine - biosynthesis / Base Sequence / biosynthesis / Cauliflower mosaic virus / CAULIMOVIRUS / Complementary DNA / Conserved Sequence / Darkness / drug effects / enzyme activity / enzymology / EXPRESION GENICA / EXPRESSION DES GENES / GENE / gene expression / Gene expression regulation / Gene Expression Regulation, Enzymologic / Gene Expression Regulation, Enzymologic - radiation effects / Gene Expression Regulation, Plant / Gene Expression Regulation, Plant - radiation effects / GENES / Genes, Plant / Genes, Plant - genetics / Genetic Complementation Test / Genetics / Glutamine / Glutamine - biosynthesis / Homozygote / Leaves / Life Sciences / Light / LUMIERE / LUZ / Messenger RNA / Molecular Sequence Data / NICOTIANA / Nicotiana - enzymology / Nicotiana - genetics / Nicotiana plumbaginifolia / Nitrate Reductase / Nitrate Reductases / Nitrate Reductases - biosynthesis / Nitrate Reductases - drug effects / Nitrate Reductases - genetics / Nitrates / oxidoreductases / OXIDORREDUCTASAS / OXYDOREDUCTASE / Peptides / Peptides - analysis / pharmacology / Phosphorylation / PLANTAS TRANSGENICAS / PLANTE TRANSGENIQUE / Plants / Plants genetics / Plants, Genetically Modified / Plants, Toxic / promoter regions / Protein Processing, Post-Translational / Proteins / Quaternary ammonium compounds / radiation effects / recombinant DNA / RNA Processing, Post-Transcriptional / RNA, Plant / RNA, Plant - analysis / Sequence Deletion / Sequence Homology, Amino Acid / structural genes / Tobacco / Transgenic plants / VIRUS DE LAS PLANTAS / VIRUS DES VEGETAUX / Yeasts / Yeasts - genetics