Assembly of the Complexes of the Oxidative Phosphorylation System in Land Plant Mitochondria

Plant mitochondria play a major role during respiration by producing the ATP required for metabolism and growth. ATP is produced during oxidative phosphorylation (OXPHOS), a metabolic pathway coupling electron transfer with ADP phosphorylation via the formation and release of a proton gradient across the inner mitochondrial membrane. The OXPHOS system is composed of large, multiprotein complexes coordinating metal-containing cofactors for the transfer of electrons. In this review, we summarize the current state of knowledge about assembly of the OXPHOS complexes in land plants. We present the different steps involved in the formation of functional complexes and the regulatory mechanisms controlling the assembly pathways. Because several assembly steps have been found to be ancestral in plants—compared with those described in fungal and animal models—we discuss the evolutionary dynamics that lead to the conservation of ancestral pathways in land plant mitochondria.

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Stress signalling dynamics of the mitochondrial electron transport chain and oxidative phosphorylation system in higher plants

Annals of Botany ◽

10.1093/aob/mcz184 ◽

2019 ◽

Vol 125 (5) ◽

pp. 721-736 ◽

Cited By ~ 4

Author(s):

Corentin Dourmap ◽

Solène Roque ◽

Amélie Morin ◽

Damien Caubrière ◽

Margaux Kerdiles ◽

...

Keyword(s):

Climate Change ◽

Electron Transport ◽

Oxidative Phosphorylation ◽

Electron Transport Chain ◽

Plant Mitochondria ◽

Mitochondrial Electron Transport Chain ◽

Oxidative Phosphorylation System ◽

Transport Chain ◽

Wide Range ◽

Stress Signalling

Abstract Background Mitochondria play a diversity of physiological and metabolic roles under conditions of abiotic or biotic stress. They may be directly subjected to physico-chemical constraints, and they are also involved in integrative responses to environmental stresses through their central position in cell nutrition, respiration, energy balance and biosyntheses. In plant cells, mitochondria present various biochemical peculiarities, such as cyanide-insensitive alternative respiration, and, besides integration with ubiquitous eukaryotic compartments, their functioning must be coupled with plastid functioning. Moreover, given the sessile lifestyle of plants, their relative lack of protective barriers and present threats of climate change, the plant cell is an attractive model to understand the mechanisms of stress/organelle/cell integration in the context of environmental stress responses. Scope The involvement of mitochondria in this integration entails a complex network of signalling, which has not been fully elucidated, because of the great diversity of mitochondrial constituents (metabolites, reactive molecular species and structural and regulatory biomolecules) that are linked to stress signalling pathways. The present review analyses the complexity of stress signalling connexions that are related to the mitochondrial electron transport chain and oxidative phosphorylation system, and how they can be involved in stress perception and transduction, signal amplification or cell stress response modulation. Conclusions Plant mitochondria are endowed with a diversity of multi-directional hubs of stress signalling that lead to regulatory loops and regulatory rheostats, whose functioning can amplify and diversify some signals or, conversely, dampen and reduce other signals. Involvement in a wide range of abiotic and biotic responses also implies that mitochondrial stress signalling could result in synergistic or conflicting outcomes during acclimation to multiple and complex stresses, such as those arising from climate change.

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Ordered Clusters of the Complete Oxidative Phosphorylation System in Cardiac Mitochondria

International Journal of Molecular Sciences ◽

10.3390/ijms22031462 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1462 ◽

Cited By ~ 1

Author(s):

Semen Nesterov ◽

Yury Chesnokov ◽

Roman Kamyshinsky ◽

Alisa Panteleeva ◽

Konstantin Lyamzaev ◽

...

Keyword(s):

Oxidative Phosphorylation ◽

Atp Synthase ◽

Electron Tomography ◽

Atp Synthesis ◽

Proton Pumps ◽

Inner Mitochondrial Membrane ◽

Oxidative Phosphorylation System ◽

Subtomogram Averaging ◽

Without Energy Dissipation ◽

Atp Synthases

The existence of a complete oxidative phosphorylation system (OXPHOS) supercomplex including both electron transport system and ATP synthases has long been assumed based on functional evidence. However, no structural confirmation of the docking between ATP synthase and proton pumps has been obtained. In this study, cryo-electron tomography was used to reveal the supramolecular architecture of the rat heart mitochondria cristae during ATP synthesis. Respirasome and ATP synthase structure in situ were determined using subtomogram averaging. The obtained reconstructions of the inner mitochondrial membrane demonstrated that rows of respiratory chain supercomplexes can dock with rows of ATP synthases forming oligomeric ordered clusters. These ordered clusters indicate a new type of OXPHOS structural organization. It should ensure the quickness, efficiency, and damage resistance of OXPHOS, providing a direct proton transfer from pumps to ATP synthase along the lateral pH gradient without energy dissipation.

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Assembly of mammalian oxidative phosphorylation complexes I–V and supercomplexes

Essays in Biochemistry ◽

10.1042/ebc20170098 ◽

2018 ◽

Vol 62 (3) ◽

pp. 255-270 ◽

Cited By ~ 55

Author(s):

Alba Signes ◽

Erika Fernandez-Vizarra

Keyword(s):

Oxidative Phosphorylation ◽

Current Knowledge ◽

Structural Components ◽

Inner Mitochondrial Membrane ◽

Catalytic Activities ◽

Oxidative Phosphorylation System ◽

Core Proteins ◽

Number Of Factors ◽

The Individual ◽

Prosthetic Groups

The assembly of the five oxidative phosphorylation system (OXPHOS) complexes in the inner mitochondrial membrane is an intricate process. The human enzymes comprise core proteins, performing the catalytic activities, and a large number of ‘supernumerary’ subunits that play essential roles in assembly, regulation and stability. The correct addition of prosthetic groups as well as chaperoning and incorporation of the structural components require a large number of factors, many of which have been found mutated in cases of mitochondrial disease. Nowadays, the mechanisms of assembly for each of the individual complexes are almost completely understood and the knowledge about the assembly factors involved is constantly increasing. On the other hand, it is now well established that complexes I, III and IV interact with each other, forming the so-called respiratory supercomplexes or ‘respirasomes’, although the pathways that lead to their formation are still not completely clear. This review is a summary of our current knowledge concerning the assembly of complexes I–V and of the supercomplexes.

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Mitochondrial Disease

10.1093/med/9780197512166.003.0123 ◽

2021 ◽

pp. 1126-1133

Author(s):

Radhika Dhamija ◽

Erin Conboy ◽

Ralitza H. Gavrilova

Keyword(s):

Oxidative Phosphorylation ◽

Mitochondrial Membrane ◽

Protein Complexes ◽

Mitochondrial Diseases ◽

Mendelian Inheritance ◽

Inner Mitochondrial Membrane ◽

Oxidative Phosphorylation System ◽

Transport Chain ◽

Membrane Bound ◽

Multimeric Protein

Primary mitochondrial diseases are a heterogeneous group of disorders that result from defects of the oxidative phosphorylation system of the mitochondria. Often underrecognized, mitochondrial diseases are uncommon (estimated incidence, 1 in 10,000 live births). Mitochondria are double-membrane–bound cytoplasmic organelles whose primary function is to provide energy (ie, adenosine triphosphate [ATP]) from the breakdown of carbohydrates, protein, and lipids by means of the electron transport chain and the oxidative phosphorylation system. The respiratory chain of mitochondria, located in the inner mitochondrial membrane, consists of 5 multimeric protein complexes (complexes I-IV and ATP synthase [complex V]). The structural proteins of these complexes are encoded by both mitochondrial and nuclear genes. Therefore, primary mitochondrial disorders can follow a maternal or mendelian inheritance pattern.

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Upregulation of COX4-2 via HIF-1α in Mitochondrial COX4-1 Deficiency

Cells ◽

10.3390/cells10020452 ◽

2021 ◽

Vol 10 (2) ◽

pp. 452

Author(s):

Liza Douiev ◽

Chaya Miller ◽

Shmuel Ruppo ◽

Hadar Benyamini ◽

Bassam Abu-Libdeh ◽

...

Keyword(s):

Oxygen Consumption ◽

Oxidative Phosphorylation ◽

Nuclear Localization ◽

Target Genes ◽

Compensatory Mechanism ◽

Terminal Electron Acceptor ◽

Human Foreskin Fibroblasts ◽

Mitochondrial Respiratory Complex ◽

Mrna Transcripts ◽

Oxphos System

Cytochrome-c-oxidase (COX) subunit 4 (COX4) plays important roles in the function, assembly and regulation of COX (mitochondrial respiratory complex 4), the terminal electron acceptor of the oxidative phosphorylation (OXPHOS) system. The principal COX4 isoform, COX4-1, is expressed in all tissues, whereas COX4-2 is mainly expressed in the lungs, or under hypoxia and other stress conditions. We have previously described a patient with a COX4-1 defect with a relatively mild presentation compared to other primary COX deficiencies, and hypothesized that this could be the result of a compensatory upregulation of COX4-2. To this end, COX4-1 was downregulated by shRNAs in human foreskin fibroblasts (HFF) and compared to the patient’s cells. COX4-1, COX4-2 and HIF-1α were detected by immunocytochemistry. The mRNA transcripts of both COX4 isoforms and HIF-1 target genes were quantified by RT-qPCR. COX activity and OXPHOS function were measured by enzymatic and oxygen consumption assays, respectively. Pathways were analyzed by CEL-Seq2 and by RT-qPCR. We demonstrated elevated COX4-2 levels in the COX4-1-deficient cells, with a concomitant HIF-1α stabilization, nuclear localization and upregulation of the hypoxia and glycolysis pathways. We suggest that COX4-2 and HIF-1α are upregulated also in normoxia as a compensatory mechanism in COX4-1 deficiency.

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Supramolecular structure of the mitochondrial oxidative phosphorylation system. VOLUME 282 (2007) PAGES 1-4

Journal of Biological Chemistry ◽

10.1016/s0021-9258(20)59712-3 ◽

2008 ◽

Vol 283 (29) ◽

pp. 20612

Author(s):

Egbert J. Boekema ◽

Hans-Peter Braun

Keyword(s):

Oxidative Phosphorylation ◽

Supramolecular Structure ◽

Mitochondrial Oxidative Phosphorylation ◽

Oxidative Phosphorylation System ◽

System Volume

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Epilepsy in Mitochondrial Diseases—Current State of Knowledge on Aetiology and Treatment

Children ◽

10.3390/children8070532 ◽

2021 ◽

Vol 8 (7) ◽

pp. 532

Author(s):

Dorota Wesół-Kucharska ◽

Dariusz Rokicki ◽

Aleksandra Jezela-Stanek

Keyword(s):

Oxidative Phosphorylation ◽

Mitochondrial Dysfunction ◽

Mitochondrial Disease ◽

Clinical Picture ◽

Poor Prognosis ◽

Treatment Options ◽

Mitochondrial Diseases ◽

Energy Deficit ◽

Atp Production ◽

Current State

Mitochondrial diseases are a heterogeneous group of diseases resulting from energy deficit and reduced adenosine triphosphate (ATP) production due to impaired oxidative phosphorylation. The manifestation of mitochondrial disease is usually multi-organ. Epilepsy is one of the most common manifestations of diseases resulting from mitochondrial dysfunction, especially in children. The onset of epilepsy is associated with poor prognosis, while its treatment is very challenging, which further adversely affects the course of these disorders. Fortunately, our knowledge of mitochondrial diseases is still growing, which gives hope for patients to improve their condition in the future. The paper presents the pathophysiology, clinical picture and treatment options for epilepsy in patients with mitochondrial disease.

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