To investigate the phosphorylation of the NDH-F subunit of the thylakoid Ndh complex, we constructed three site-directed mutant transgenic tobaccos (Nicotiana tabacum) (T181A, T181S and T181D) in which the (541)ACT(543) triplet encoding the Thr-181 has been substituted by GCT, TCT or GAT encoding alanine, serine and aspartic acid, respectively. Western blots with phospho-threonine antibody detected the 73 kD NDH-F phosphorylated polypeptide in control but not in mutant tobaccos. Differences in Ndh activity, chlorophyll fluorescence and photosynthesis among mutants and control plant demonstrate the key role of the phosphorylation of conserved Thr-181 in the activity and function of the Ndh complex. The substitution of aspartic acid for threonine in T181D mimics the presumable activation effects of the threonine phosphorylation in Ndh activity, post-illumination increase of chlorophyll fluorescence and photosynthesis rapid responses to changing light intensities. A tentative role of the phosphorylation-activated Ndh complex is suggested to poise the redox level and, consequently, optimizing the rate of cyclic electron transport under field conditions.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.bbabio.2009.03.001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cryo-EM structure of the NDH-PSI-LHCI supercomplex from Spinacia oleracea.
Nat Struct Mol Biol
January 2025
Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
The nicotinamide adenine dinucleotide phosphate (NADPH) dehydrogenase (NDH) complex is crucial for photosynthetic cyclic electron flow and respiration, transferring electrons from ferredoxin to plastoquinone while transporting H across the chloroplast membrane. This process boosts adenosine triphosphate production, regardless of NADPH levels. In flowering plants, NDH forms a supercomplex with photosystem I, enhancing its stability under high light.
View Article and Find Full Text PDFPhysiological relevance, localization and substrate specificity of the alternative (type II) mitochondrial NADH dehydrogenases of .
Front Microbiol
December 2024
Department of Biotechnology, Delft University of Technology, Delft, Netherlands.
Mitochondria from harbor a branched electron-transport chain containing a proton-pumping Complex I NADH dehydrogenase and three Type II NADH dehydrogenases (NDH-2). To investigate the physiological role, localization and substrate specificity of these enzymes, the growth of various NADH dehydrogenase knockout mutants was quantitatively characterized in shake-flask and chemostat cultures, followed by oxygen-uptake experiments with isolated mitochondria. NAD(P)H:quinone oxidoreduction of the three NDH-2 were individually assessed.
View Article and Find Full Text PDFEmbracing native diversity to enhance the maximum quantum efficiency of photosystem II in maize.
Plant Physiol
December 2024
Plant Breeding, TUM School of Life Sciences, Technical University of Munich, Freising 85354, Germany.
The sustainability of maize cultivation would benefit tremendously from early sowing, but is hampered by low temperatures during early development in temperate climates. We show that allelic variation within the gene encoding subunit M of the NADH-dehydrogenase-like (NDH) complex (ndhm1) in a European maize landrace affects several quantitative traits that are relevant during early development in cold climates through NDH-mediated cyclic electron transport around photosystem I, a process crucial for photosynthesis and photoprotection. Beginning with a genome-wide association study for maximum potential quantum yield of photosystem II in dark-adapted leaves (Fv/Fm), we capitalized on the large phenotypic effects of a hAT transposon insertion in ndhm1 on multiple quantitative traits (early plant height [EPH], Fv/Fm, chlorophyll content, and cold tolerance) caused by the reduced protein levels of NDHM and associated NDH components.
View Article and Find Full Text PDFAlternative NADH dehydrogenase: A complex I backup, a drug target, and a tool for mitochondrial gene therapy.
Biochim Biophys Acta Bioenerg
November 2024
Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenka, 76018, Ivano-Frankivsk, Ukraine. Electronic address:
Alternative NADH dehydrogenase, also known as type II NADH dehydrogenase (NDH-2), catalyzes the same redox reaction as mitochondrial respiratory chain complex I. Specifically, it oxidizes reduced nicotinamide adenine dinucleotide (NADH) while simultaneously reducing ubiquinone to ubiquinol. However, unlike complex I, this enzyme is non-proton pumping, comprises of a single subunit, and is resistant to rotenone.
View Article and Find Full Text PDFModulating Liposome Surface Charge for Maximized ATP Regeneration in Synthetic Nanovesicles.
ACS Synth Biol
December 2024
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern 3012, Switzerland.
Article Synopsis
- In vitro reconstructed minimal respiratory chains are used to study how enzyme components interact within their environment, particularly focusing on the coreconstitution of cytochrome oxidase and ATP synthase in liposomes.
- The study explores using natural long-chain ubiquinone and various electron donors like succinate or NADH, while revealing that negatively charged lipids are necessary for effective enzyme activity but also reduce ATP synthesis rates.
- To optimize enzyme orientation and ATP production, researchers utilize ionizable lipids that can switch charges based on pH, successfully enhancing ATP synthesis rates by aligning cytochrome oxidase for better function with NDH-2.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!