scholarly journals The organization of NADH dehydrogenase polypeptides in the inner mitochondrial membrane

1980 ◽  
Vol 185 (2) ◽  
pp. 315-326 ◽  
Author(s):  
S Smith ◽  
C I Ragan
Keyword(s):  
Complex I ◽  
Mitochondrial Membrane ◽  
Nadh Dehydrogenase ◽  
Inner Mitochondrial Membrane ◽  
Submitochondrial Particles ◽  
Cytoplasmic Face ◽  
The Matrix

The organization of the constituent polypeptides of mitochondrial NADH dehydrogenase was studied by using two membrane-impermeable probes, diazobenzene[35S]sulphonate and lactoperoxidase-catalysed radioiodination. The incorporation of label into the subunits of the isolated enzyme was compared with that obtained with enzyme immunoprecipitated from labelled mitochondria or inverted submitochondrial particles. On the basis of accessibility to these two labels, we divide the polypeptides of Complex I into five groups: those that are apparently buried in the enzyme, those that are accessible to labelling in the isolated enzyme but not in the membrane, those that are exposed on the cytoplasmic face of the membrane, those that are exposed on the matrix face and finally those that are exposed on both faces and are therefore transmembranous. We conclude that NADH dehydrogenase is asymmetrically organized across the inner mitochondrial membrane.

scholarly journals A ferredoxin bridge connects the two arms of plant mitochondrial complex I

2020 ◽  
Author(s):  
Niklas Klusch ◽  
Jennifer Senkler ◽  
Özkan Yildiz ◽  
Werner Kühlbrandt ◽  
Hans-Peter Braun
Keyword(s):  
Arabidopsis Thaliana ◽  
Complex I ◽  
Mitochondrial Membrane ◽  
Mitochondrial Complex I ◽  
Mitochondrial Complex ◽  
Inner Mitochondrial Membrane ◽  
Main Site ◽  
The Matrix ◽  
Quinol Binding ◽  
Complex I Activity

SUMMARYMitochondrial complex I is the main site for electron transfer to the respiratory chain and generates much of the proton gradient across the inner mitochondrial membrane. It is composed of two arms, which form a conserved L-shape. We report the structures of the intact, 47-subunit mitochondrial complex I from Arabidopsis thaliana and from the green alga Polytomella sp. at 3.2 and 3.3 Å resolution. In both, a heterotrimeric γ-carbonic anhydrase domain is attached to the membrane arm on the matrix side. Two states are resolved in A. thaliana complex I, with different angles between the two arms and different conformations of the ND1 loop near the quinol binding site. The angle appears to depend on a bridge domain, which links the peripheral arm to the membrane arm and includes an unusual ferredoxin. We suggest that the bridge domain regulates complex I activity.One sentence summaryThe activity of complex I depends on the angel between its two arms, which, in plants, is adjusted by a protein bridge that includes an unusual ferredoxin.The authors responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) are: Hans-Peter Braun ([email protected]) and Werner Kühlbrandt ([email protected]).

scholarly journals Transmembrane organization of mitochondrial NADH dehydrogenase as revealed by radiochemical labelling and cross-linking

1988 ◽  
Vol 256 (2) ◽  
pp. 529-535 ◽  
Author(s):  
S D Patel ◽  
M W J Cleeter ◽  
C I Ragan
Keyword(s):  
Nadh Dehydrogenase ◽  
Cross Linking ◽  
Submitochondrial Particles ◽  
Mitochondrial Inner Membrane ◽  
Cytoplasmic Face ◽  
The Matrix ◽  
Dimethyl Suberimidate ◽  
Membrane Reaction ◽  
Cytoplasmic Side ◽  
Chemical Cross Linking

The organization of bovine heart NADH dehydrogenase in the mitochondrial inner membrane was investigated by chemical cross-linking and radiolabelling with [125I]iododiazobenzenesulphonate (IDABS). Mitochondria or submitochondrial particles were cross-linked with disulphosuccinimidyl tartrate and dimethyl suberimidate, and dimeric products containing subunits of the NADH dehydrogenase were analysed by Western blotting with subunit-specific antisera. Cross-linking of mitochondria gave rise to (49 + 30) kDa and (49 + 19) kDa dimers and an additional dimer containing the 30 kDa subunit. Cross-linking of submitochondrial particles gave rise to (75 + 51) kDa, (75 + 30) kDa and (49 + 13) kDa dimers and a further dimer containing the 30 kDa subunit. We conclude that the 49 kDa and 30 kDa subunits are transmembranous, the 19 kDa subunit is exposed on the cytoplasmic face of the membrane, whereas the 75, 51 and 13 kDa subunits are exposed on the matrix face of the membrane. Reaction of the isolated enzyme with IDABS results in labelling of 75, 49, 42, 33, 30, 13 and 10 kDa subunits. From experiments in which mitochondria or submitochondrial particles were first labelled and NADH dehydrogenase then isolated by immunoprecipitation, it was found that labelling of the 49 kDa subunit occurs predominantly from the cytoplasmic side of the membrane. On the other hand, labelling of the 75, 13 and 10 kDa subunits occurs predominantly from the matrix side of the membrane, whereas the 30 and 33 kDa subunits are heavily labelled from either side. These findings are consistent with those obtained from cross-linking.

scholarly journals A ferredoxin bridge connects the two arms of plant mitochondrial complex I

2021 ◽  
Author(s):  
Niklas Klusch ◽  
Jennifer Senkler ◽  
Özkan Yildiz ◽  
Werner Kühlbrandt ◽  
Hans-Peter Braun
Keyword(s):  
Complex I ◽  
Nadh Dehydrogenase ◽  
Mitochondrial Complex I ◽  
Mitochondrial Complex ◽  
Nadh Dehydrogenase Subunit ◽  
Inner Mitochondrial Membrane ◽  
Main Site ◽  
Membrane Complex ◽  
The Matrix ◽  
Quinol Binding

Abstract Mitochondrial complex I is the main site for electron transfer to the respiratory chain and generates much of the proton gradient across the inner mitochondrial membrane. Complex I is composed of two arms, which form a conserved L-shape. We report the structures of the intact, 47-subunit mitochondrial complex I from Arabidopsis thaliana and the 51-subunit complex I from the green alga Polytomella sp., both at around 2.9 Å resolution. In both complexes, a heterotrimeric γ-carbonic anhydrase domain is attached to the membrane arm on the matrix side. Two states are resolved in A. thaliana complex I, with different angles between the two arms and different conformations of the ND1 (NADH dehydrogenase subunit 1) loop near the quinol binding site. The angle appears to depend on a bridge domain, which links the peripheral arm to the membrane arm and includes an unusual ferredoxin. We propose that the bridge domain participates in regulating the activity of plant complex I.

scholarly journals High-resolution cryo-EM structures of respiratory complex I: Mechanism, assembly, and disease

2019 ◽  
Vol 5 (12) ◽  
pp. eaax9484 ◽  
Author(s):  
Kristian Parey ◽  
Outi Haapanen ◽  
Vivek Sharma ◽  
Harald Köfeler ◽  
Thomas Züllig ◽  
...  
Keyword(s):  
Complex I ◽  
Mitochondrial Membrane ◽  
Electrochemical Gradient ◽  
Inner Mitochondrial Membrane ◽  
Respiratory Complex ◽  
Access Path ◽  
Respiratory Complex I ◽  
Assembly Intermediate ◽  
The One ◽  
Complex I Assembly

Respiratory complex I is a redox-driven proton pump, accounting for a large part of the electrochemical gradient that powers mitochondrial adenosine triphosphate synthesis. Complex I dysfunction is associated with severe human diseases. Assembly of the one-megadalton complex I in the inner mitochondrial membrane requires assembly factors and chaperones. We have determined the structure of complex I from the aerobic yeast Yarrowia lipolytica by electron cryo-microscopy at 3.2-Å resolution. A ubiquinone molecule was identified in the access path to the active site. The electron cryo-microscopy structure indicated an unusual lipid-protein arrangement at the junction of membrane and matrix arms that was confirmed by molecular simulations. The structure of a complex I mutant and an assembly intermediate provide detailed molecular insights into the cause of a hereditary complex I–linked disease and complex I assembly in the inner mitochondrial membrane.

scholarly journals CO2 and HCO3- Permeability of the Rat Liver Mitochondrial Membrane

2016 ◽  
Vol 39 (5) ◽  
pp. 2014-2024 ◽  
Author(s):  
Mariela Arias-Hidalgo ◽  
Jan Hegermann ◽  
Georgios Tsiavaliaris ◽  
Fabrizio Carta ◽  
Claudiu T. Supuran ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Mitochondrial Membrane ◽  
Gas Permeability ◽  
Alternative Pathway ◽  
Biological Membrane ◽  
Red Cell ◽  
Inner Mitochondrial Membrane ◽  
Red Cell Membrane ◽  
The Matrix ◽  
Rat Livers

Background/Aims: Across the mitochondrial membrane an exceptionally intense exchange of O2 and CO2 occurs. We have asked, 1) whether the CO2 permeability, PM,CO2, of this membrane is also exceptionally high, and 2) whether the mitochondrial membrane is sufficiently permeable to HCO3- to make passage of this ion an alternative pathway for exit of metabolically produced CO2. Methods: The two permeabilities were measured using the previously published mass spectrometric 18O exchange technique to study suspensions of mitochondria freshly isolated from rat livers. The mitochondria were functionally and morphologically in excellent condition. Results: The intramitochondrial CA activity was exclusively localized in the matrix. PM,CO2 of the inner mitochondrial membrane was 0.33 (SD ± 0.03) cm/s, which is the highest value reported for any biological membrane, even two times higher than PM,CO2 of the red cell membrane. PM,HCO3- was 2· 10-6 (SD ± 2· 10-6) cm/s and thus extremely low, almost 3 orders of magnitude lower than PM,HCO3- of the red cell membrane. Conclusion: The inner mitochondrial membrane is almost impermeable to HCO3- but extremely permeable to CO2. Since gas channels are absent, this membrane constitutes a unique example of a membrane of very high gas permeability due to its extremely low content of cholesterol.

scholarly journals Oxidation and reduction of pyridine nucleotides in alamethicin-permeabilized plant mitochondria

2004 ◽  
Vol 380 (1) ◽  
pp. 193-202 ◽  
Author(s):  
Fredrik I. JOHANSSON ◽  
Agnieszka M. MICHALECKA ◽  
Ian M. MØLLER ◽  
Allan G. RASMUSSON
Keyword(s):  
Electron Transport ◽  
Complex I ◽  
Electron Transport Chain ◽  
Nadh Dehydrogenase ◽  
Plant Mitochondria ◽  
Inner Mitochondrial Membrane ◽  
Intact Cells ◽  
Transport Chain ◽  
Invasive Method

The inner mitochondrial membrane is selectively permeable, which limits the transport of solutes and metabolites across the membrane. This constitutes a problem when intramitochondrial enzymes are studied. The channel-forming antibiotic AlaM (alamethicin) was used as a potentially less invasive method to permeabilize mitochondria and study the highly branched electron-transport chain in potato tuber (Solanum tuberosum) and pea leaf (Pisum sativum) mitochondria. We show that AlaM permeabilized the inner membrane of plant mitochondria to NAD(P)H, allowing the quantification of internal NAD(P)H dehydrogenases as well as matrix enzymes in situ. AlaM was found to inhibit the electron-transport chain at the external Ca2+-dependent rotenone-insensitive NADH dehydrogenase and around complexes III and IV. Nevertheless, under optimal conditions, especially complex I-mediated NADH oxidation in AlaM-treated mitochondria was much higher than what has been previously measured by other techniques. Our results also show a difference in substrate specificities for complex I in mitochondria as compared with inside-out submitochondrial particles. AlaM facilitated the passage of cofactors to and from the mitochondrial matrix and allowed the determination of NAD+ requirements of malate oxidation in situ. In summary, we conclude that AlaM provides the best method for quantifying NADH dehydrogenase activities and that AlaM will prove to be an important method to study enzymes under conditions that resemble their native environment not only in plant mitochondria but also in other membrane-enclosed compartments, such as intact cells, chloroplasts and peroxisomes.

Cd2+-induced swelling-contraction dynamics in isolated kidney cortex mitochondria: role of Ca2+ uniporter, K+ cycling, and protonmotive force

2005 ◽  
Vol 289 (3) ◽  
pp. C656-C664 ◽  
Author(s):  
Wing-Kee Lee ◽  
Malte Spielmann ◽  
Ulrich Bork ◽  
Frank Thévenod
Keyword(s):  
Mitochondrial Membrane ◽  
Rat Kidney ◽  
Choline Chloride ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Kidney Cortex ◽  
Protonmotive Force ◽  
Inner Mitochondrial Membrane ◽  
Rat Kidney Cortex ◽  
The Matrix

The nephrotoxic metal Cd2+ causes mitochondrial damage and apoptosis of kidney proximal tubule cells. A K+ cycle involving a K+ uniporter and a K+/H+ exchanger in the inner mitochondrial membrane (IMM) is thought to contribute to the maintenance of the structural and functional integrity of mitochondria. In the present study, we have investigated the effect of Cd2+ on K+ cycling in rat kidney cortex mitochondria. Cd2+ (EC50 ∼19 μM) induced swelling of nonenergized mitochondria suspended in isotonic salt solutions according to the sequence KCl = NaCl > LiCl ≫ choline chloride. Cd2+-induced swelling of energized mitochondria had a similar EC50 value and showed the same cation dependence but was followed by a spontaneous contraction. Mitochondrial Ca2+ uniporter (MCU) blockers, but not permeability transition pore inhibitors, abolished swelling, suggesting the need for Cd2+ influx through the MCU for swelling to occur. Complete loss of mitochondrial membrane potential (ΔΨm) induced by K+ influx did not prevent contraction, but addition of the K+/H+ exchanger blocker, quinine (1 mM), or the electroneutral protonophore nigericin (0.4 μM), abolished contraction, suggesting the mitochondrial pH gradient (ΔpHm) driving contraction. Accordingly, a quinine-sensitive partial dissipation of ΔpHm was coincident with the swelling-contraction phase. The data indicate that Cd2+ enters the matrix through the MCU to activate a K+ cycle. Initial K+ load via a Cd2+-activated K+ uniporter in the IMM causes osmotic swelling and breakdown of ΔΨm and triggers quinine-sensitive K+/H+ exchange and contraction. Thus Cd2+-induced activation of a K+ cycle contributes to the dissipation of the mitochondrial protonmotive force.

scholarly journals Structural organization of mitochondrial human complex I: role of the ND4 and ND5 mitochondria-encoded subunits and interaction with prohibitin

2004 ◽  
Vol 383 (3) ◽  
pp. 491-499 ◽  
Author(s):  
Ingrid BOURGES ◽  
Claire RAMUS ◽  
Bénédicte MOUSSON de CAMARET ◽  
Réjane BEUGNOT ◽  
Claire REMACLE ◽  
...  
Keyword(s):  
Complex I ◽  
Nadh Dehydrogenase ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Membrane Association ◽  
Oxidoreductase Activity ◽  
Mitochondrial Inner Membrane ◽  
The Matrix ◽  
Complex I Assembly ◽  
Human Complex

Mitochondria-encoded ND (NADH dehydrogenase) subunits, as components of the hydrophobic part of complex I, are essential for NADH:ubiquinone oxidoreductase activity. Mutations or lack of expression of these subunits have significant pathogenic consequences in humans. However, the way these events affect complex I assembly is poorly documented. To understand the effects of particular mutations in ND subunits on complex I assembly, we studied four human cell lines: ND4 non-expressing cells, ND5 non-expressing cells, and rho° cells that do not express any ND subunits, in comparison with normal complex I control cells. In control cells, all the seven analysed nuclear-encoded complex I subunits were found to be attached to the mitochondrial inner membrane, except for the 24 kDa subunit, which was nearly equally partitioned between the membranes and the matrix. Absence of a single ND subunit, or even all the seven ND subunits, caused no major changes in the nuclear-encoded complex I subunit content of mitochondria. However, in cells lacking ND4 or ND5, very low amounts of 24 kDa subunit were found associated with the membranes, whereas most of the other nuclear-encoded subunits remained attached. In contrast, membrane association of most of the nuclear subunits was significantly reduced in the absence of all seven ND proteins. Immunopurification detected several subcomplexes. One of these, containing the 23, 30 and 49 kDa subunits, also contained prohibitin. This is the first description of prohibitin interaction with complex I subunits and suggests that this protein might play a role in the assembly or degradation of mitochondrial complex I.

scholarly journals Accessory Subunits of the Matrix Arm of Mitochondrial Complex I with a Focus on Subunit NDUFS4 and Its Role in Complex I Function and Assembly

Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 455
Author(s):  
Flora Kahlhöfer ◽  
Max Gansen ◽  
Volker Zickermann
Keyword(s):  
Complex I ◽  
Hot Spot ◽  
Proton Translocation ◽  
Chain Complex ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Inner Mitochondrial Membrane ◽  
Accessory Subunits ◽  
The Matrix ◽  
Assembly Factor ◽  
Accessory Subunit

NADH:ubiquinone-oxidoreductase (complex I) is the largest membrane protein complex of the respiratory chain. Complex I couples electron transfer to vectorial proton translocation across the inner mitochondrial membrane. The L shaped structure of complex I is divided into a membrane arm and a matrix arm. Fourteen central subunits are conserved throughout species, while some 30 accessory subunits are typically found in eukaryotes. Complex I dysfunction is associated with mutations in the nuclear and mitochondrial genome, resulting in a broad spectrum of neuromuscular and neurodegenerative diseases. Accessory subunit NDUFS4 in the matrix arm is a hot spot for mutations causing Leigh or Leigh-like syndrome. In this review, we focus on accessory subunits of the matrix arm and discuss recent reports on the function of accessory subunit NDUFS4 and its interplay with NDUFS6, NDUFA12, and assembly factor NDUFAF2 in complex I assembly.

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