+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Characterization of Nitrate Reductase from Light- and Dark-Exposed Leaves (Comparison of Different Species and Effects of 14-3-3 Inhibitor Proteins)



Characterization of Nitrate Reductase from Light- and Dark-Exposed Leaves (Comparison of Different Species and Effects of 14-3-3 Inhibitor Proteins)



Plant Physiology 114(4): 1377-1383



Nitrate reductase (NR) was extracted and partially purified from leaves of squash (Curcurbita maxima), spinach (Spinacia oleracea), and three transgenic Nicotiana plumbaginifolia leaves in the presence of phosphatase inhibitors to preserve its phosphorylation state. Purified squash NR showed activation by substrates (hysteresis) when prepared from leaves in the light as well as in darkness. A 14-3-3 protein known to inhibit phosphorylated spinach NR in the presence of Mg2+ decreased by 70 to 85% the activity of purified NR from dark-exposed leaves, whereas NR from light-exposed leaves decreased by 10 to 25%. Apparent lack of posttranslational NR regulation in a transgenic N. plumbaginifolia expressing an NR construct with an N-terminal deletion ([delta]NR) may be explained by more easy dissociation of 14-3-3 proteins from [delta]NR. Partially purified [delta]NR was, however, inhibited by 14-3-3 protein, and the binding constant of 14-3-3 protein (4 x 108 M-1) and the NR-inhibiting protein concentration that results in a 50% reduction of free NR (2.5 nM) were the same for NR and [delta]NR. Regulation of NR activity by phosphorylation and binding of 14-3-3 protein was a general feature for all plants tested, whereas activation by substrates as a possible regulation mechanism was verified only for squash.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 002775823

Download citation: RISBibTeXText

PMID: 12223776

DOI: 10.1104/pp.114.4.1377


Related references

Effects of continuous light/dark and 2,5-norbornadiene on nitrate reductase activity in spinach leaves. Bulletin of the Polish Academy of Sciences Biological Sciences 51(1): 9-15, 2003

cDNA Clones for Corn Leaf NADH:Nitrate Reductase and Chloroplast NAD(P):Glyceraldehyde-3-Phosphate Dehydrogenase : Characterization of the Clones and Analysis of the Expression of the Genes in Leaves as Influenced by Nitrate in the Light and Dark. Plant Physiology 90(3): 792-798, 1989

Complementary dna clones for corn leaf nadh nitrate reductase and chloroplast nad ppositive glyceraldehyde 3 phosphate dehydrogenase characterization of the clones and analysis of the expression of the genes in leaves as influenced by nitrate in the light and dark. Plant Physiology (Rockville) 90(3): 792-798, 1989

Regulation of nitrate reductase activity by nitrate during light-dark transition in detached oat leaves. Plant & Cell Physiology 36(7): 1399-1403, 1995

Decrease of Nitrate Reductase Activity in Spinach Leaves during a Light-Dark Transition. Plant Physiology 98(2): 573-577, 1992

Nitrate reductase activity of dark-grown and light-exposed etiolated field peas. Canadian Journal of Botany 51(1): 27-35, 1973

Involvement of CO2 fixation products in the light-dark modulation of nitrate reductase activity in barley leaves. Physiologia Plantarum 89(3): 577-581, 1993

Nitrate reductase activity of dark-grown and light-exposed etiolated field peas ( Pisum arvense ). Canadian Journal of Botany 51(1): 27-35, 1973

Nitrate reductase expression in maize leaves (Zea mays) during dark-light transitions. Complex effects of protein phosphatase inhibitors on enzyme activity, protein synthesis and transcript levels. Physiologia Plantarum 98(1): 67-76, 1996

Regulation of in vivo nitrate reductase activity in cotton (Gossypium hirsutum) leaves in light and dark and the possible role of cytokinin. Indian Journal of Biochemistry & Biophysics 24(6): 326-328, 1987

Effect of ammonium and nitrate on growth and appearance of nitrate reductase and nitrite reductase in dark- and light-grown mustard seedlings. Planta 169(4): 594-599, 1986

Effects of light, bicarbonate, and inhibitors on increase in in vivo nitrate reductase activity in maize leaves in the presence of ammonium or nitrate. Biochemie und Physiologie der Pflanzen78(6-7): 449-455, 1983

Effects of light bi carbonate and inhibitors on increase in in vivo nitrate reductase activity in maize zea mays leaves in the presence of ammonium or nitrate. Biochemie und Physiologie der Pflanzen (BPP) 178(6-7): 449-455, 1983

Assimilation of [N]Nitrate and [N]Nitrite in Leaves of Five Plant Species under Light and Dark Conditions. Plant Physiology 71(2): 291-294, 1983

Assimilation of (15N)nitrate and (15N)nitrite in leaves of five plant species under light and dark conditions. Plant Physiology 71: 1-4, 1983