scholarly journals Inactivation of mitochondrial Complex I stimulates chloroplast ATPase in Physcomitrella (Physcomitrium patens)

2020 ◽  
Author(s):  
Marco Mellon ◽  
Mattia Storti ◽  
Antoni Mateu Vera Vives ◽  
David M. Kramer ◽  
Alessandro Alboresi ◽  
...  
Keyword(s):  
Complex I ◽  
Respiratory Activity ◽  
Photosynthetic Apparatus ◽  
Mitochondrial Complex ◽  
Photosynthetic Organisms ◽  
Photosystems I And Ii ◽  
Transport Chain ◽  
Ultimate Source ◽  
Photosynthetic Control ◽  
Atp Supply

AbstractWhile light is the ultimate source of energy for photosynthetic organisms, mitochondrial respiration is still fundamental for supporting metabolism demand during the night or in heterotrophic tissues. Respiration is also important for the metabolism of photosynthetically active cells, acting as a sink for excess reduced molecules and source of substrates for anabolic pathways. In this work, we isolated Physcomitrella (Physcomitrium patens) plants with altered respiration by inactivating Complex I of the mitochondrial electron transport chain by independent targeting of two essential subunits. Results show that the inactivation of Complex I causes a strong growth impairment even in fully autotrophic conditions in tissues where all cells are photosynthetically active. Complex I mutants show major alterations in the stoichiometry of respiratory complexes while the composition of photosynthetic apparatus was substantially unaffected. Complex I mutants showed altered photosynthesis with higher yields of both Photosystems I and II. These are the consequence of a higher chloroplast ATPase activity that also caused a smaller ΔpH formation across thylakoid membranes as well as decreased photosynthetic control on cytochrome b6f, possibly to compensate for a deficit in ATP supply relative to demand in Complex I mutants. These results demonstrate that alteration of respiratory activity directly impacts photosynthesis in P. patens and that metabolic interaction between organelles is essential in their ability to use light energy for growth.

scholarly journals Oxygen and ROS in Photosynthesis

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 91 ◽  
Author(s):  
Sergey Khorobrykh ◽  
Vesa Havurinne ◽  
Heta Mattila ◽  
Esa Tyystjärvi
Keyword(s):  
Electron Transport Chain ◽  
Photosynthetic Apparatus ◽  
Photosynthetic Electron Transport ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Photosynthetic Organisms ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain ◽  
Regulatory Functions

Oxygen is a natural acceptor of electrons in the respiratory pathway of aerobic organisms and in many other biochemical reactions. Aerobic metabolism is always associated with the formation of reactive oxygen species (ROS). ROS may damage biomolecules but are also involved in regulatory functions of photosynthetic organisms. This review presents the main properties of ROS, the formation of ROS in the photosynthetic electron transport chain and in the stroma of chloroplasts, and ROS scavenging systems of thylakoid membrane and stroma. Effects of ROS on the photosynthetic apparatus and their roles in redox signaling are discussed.

scholarly journals The Campylobacter jejuni NADH:Ubiquinone Oxidoreductase (Complex I) Utilizes Flavodoxin Rather than NADH

2007 ◽  
Vol 190 (3) ◽  
pp. 915-925 ◽  
Author(s):  
Dilan R. Weerakoon ◽  
Jonathan W. Olson
Keyword(s):  
Campylobacter Jejuni ◽  
Complex I ◽  
Nadh Dehydrogenase ◽  
Respiratory Activity ◽  
Essential Gene ◽  
Electron Flow ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
The Novel ◽  
Wild Type ◽  
Transport Chain

ABSTRACT Campylobacter jejuni encodes 12 of the 14 subunits that make up the respiratory enzyme NADH:ubiquinone oxidoreductase (also called complex I). The two nuo genes not present in C. jejuni encode the NADH dehydrogenase, and in their place in the operon are the novel genes designated Cj1575c and Cj1574c. A series of mutants was generated in which each of the 12 nuo genes (homologues to known complex I subunits) was disrupted or deleted. Each of the nuo mutants will not grow in amino acid-based medium unless supplemented with an alternative respiratory substrate such as formate. Unlike the nuo genes, Cj1574c is an essential gene and could not be disrupted unless an intact copy of the gene was provided at an unrelated site on the chromosome. A nuo deletion mutant can efficiently respire formate but is deficient in α-ketoglutarate respiratory activity compared to the wild type. In C. jejuni, α-ketoglutarate respiration is mediated by the enzyme 2-oxoglutarate:acceptor oxidoreductase; mutagenesis of this enzyme abolishes α-ketoglutarate-dependent O2 uptake and fails to reduce the electron transport chain. The electron acceptor for 2-oxoglutarate:acceptor oxidoreductase was determined to be flavodoxin, which was also determined to be an essential protein in C. jejuni. A model is presented in which CJ1574 mediates electron flow into the respiratory transport chain from reduced flavodoxin and through complex I.

scholarly journals The long non-coding RNA Cerox1 is a post transcriptional regulator of mitochondrial complex I catalytic activity

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Tamara M Sirey ◽  
Kenny Roberts ◽  
Wilfried Haerty ◽  
Oscar Bedoya-Reina ◽  
Sebastian Rogatti-Granados ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Complex I ◽  
Noncoding Rna ◽  
Mitochondrial Complex I ◽  
Mitochondrial Complex ◽  
Non Coding Rna ◽  
Transport Chain ◽  
Species Production ◽  
Complex I Activity ◽  
Long Non Coding Rna

To generate energy efficiently, the cell is uniquely challenged to co-ordinate the abundance of electron transport chain protein subunits expressed from both nuclear and mitochondrial genomes. How an effective stoichiometry of this many constituent subunits is co-ordinated post-transcriptionally remains poorly understood. Here we show that Cerox1, an unusually abundant cytoplasmic long noncoding RNA (lncRNA), modulates the levels of mitochondrial complex I subunit transcripts in a manner that requires binding to microRNA-488-3p. Increased abundance of Cerox1 cooperatively elevates complex I subunit protein abundance and enzymatic activity, decreases reactive oxygen species production, and protects against the complex I inhibitor rotenone. Cerox1 function is conserved across placental mammals: human and mouse orthologues effectively modulate complex I enzymatic activity in mouse and human cells, respectively. Cerox1 is the first lncRNA demonstrated, to our knowledge, to regulate mitochondrial oxidative phosphorylation and, with miR-488-3p, represent novel targets for the modulation of complex I activity.

scholarly journals Atomic structure of a mitochondrial complex I intermediate from vascular plants

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Maria Maldonado ◽  
Abhilash Padavannil ◽  
Long Zhou ◽  
Fei Guo ◽  
James A Letts
Keyword(s):  
Complex I ◽  
Vascular Plants ◽  
Protein Complexes ◽  
Structural Studies ◽  
Mitochondrial Complex ◽  
Transport Chain ◽  
Accessory Subunits ◽  
Membrane Protein Complexes ◽  
Assembly Intermediate ◽  
Membrane Anchoring

Respiration, an essential metabolic process, provides cells with chemical energy. In eukaryotes, respiration occurs via the mitochondrial electron transport chain (mETC) composed of several large membrane-protein complexes. Complex I (CI) is the main entry point for electrons into the mETC. For plants, limited availability of mitochondrial material has curbed detailed biochemical and structural studies of their mETC. Here, we present the cryoEM structure of the known CI assembly intermediate CI* from Vigna radiata at 3.9 Å resolution. CI* contains CI’s NADH-binding and CoQ-binding modules, the proximal-pumping module and the plant-specific γ-carbonic-anhydrase domain (γCA). Our structure reveals significant differences in core and accessory subunits of the plant complex compared to yeast, mammals and bacteria, as well as the details of the γCA domain subunit composition and membrane anchoring. The structure sheds light on differences in CI assembly across lineages and suggests potential physiological roles for CI* beyond assembly.

scholarly journals Novel mitochondrial complex I-inhibiting peptides restrain NADH dehydrogenase activity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yao-Peng Xue ◽  
Mou-Chieh Kao ◽  
Chung-Yu Lan
Keyword(s):  
Antimicrobial Peptides ◽  
Complex I ◽  
Fungal Pathogens ◽  
Nadh Dehydrogenase ◽  
Mitochondrial Complex I ◽  
Mitochondrial Complex ◽  
Human Fungal Pathogen ◽  
New Class ◽  
Transport Chain ◽  
Nadh Dehydrogenases

Abstract The emergence of drug-resistant fungal pathogens is becoming increasingly serious due to overuse of antifungals. Antimicrobial peptides have potent activity against a broad spectrum of pathogens, including fungi, and are considered a potential new class of antifungals. In this study, we examined the activities of the newly designed peptides P-113Du and P-113Tri, together with their parental peptide P-113, against the human fungal pathogen Candida albicans. The results showed that these peptides inhibit mitochondrial complex I, specifically NADH dehydrogenase, of the electron transport chain. Moreover, P-113Du and P-113Tri also block alternative NADH dehydrogenases. Currently, most inhibitors of the mitochondrial complex I are small molecules or artificially-designed antibodies. Here, we demonstrated novel functions of antimicrobial peptides in inhibiting the mitochondrial complex I of C. albicans, providing insight in the development of new antifungal agents.

scholarly journals Cerox1 and microRNA-488-3p noncoding RNAs jointly regulate mitochondrial complex I catalytic activity

2018 ◽  
Author(s):  
Tamara M Sirey ◽  
Kenny Roberts ◽  
Wilfried Haerty ◽  
Oscar Bedoya-Reina ◽  
Sebastian Rogatti-Granados ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Complex I ◽  
Noncoding Rna ◽  
Mitochondrial Complex I ◽  
Mitochondrial Complex ◽  
Protein Subunits ◽  
Transport Chain ◽  
Species Production ◽  
Complex I Activity ◽  
Human And Mouse

AbstractTo generate energy efficiently, the cell is uniquely challenged to co-ordinate the abundance of electron transport chain protein subunits expressed from both nuclear and mitochondrial genomes. How an effective stoichiometry of this many constituent subunits is co-ordinated post-transcriptionally remains poorly understood. Here we show that Cerox1, an unusually abundant cytoplasmic long noncoding RNA (lncRNA), modulates the levels of mitochondrial complex I subunit transcripts in a manner that requires binding to microRNA-488-3p. Increased abundance of Cerox1 cooperatively elevates complex I subunit protein abundance and enzymatic activity, decreases reactive oxygen species production, and protects against the complex I inhibitor rotenone. Cerox1 function is conserved across placental mammals: human and mouse orthologues effectively modulate complex I enzymatic activity in mouse and human cells, respectively. Cerox1 is the first lncRNA demonstrated, to our knowledge, to regulate mitochondrial oxidative phosphorylation (OXPHOS) and, with miR-488-3p, represent novel targets for the modulation of complex I activity.

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