scholarly journals Assembly of the peripheral stalk of ATP synthase in human mitochondria

2020 ◽  
Vol 117 (47) ◽  
pp. 29602-29608
Author(s):  
Jiuya He ◽  
Joe Carroll ◽  
Shujing Ding ◽  
Ian M. Fearnley ◽  
Martin G. Montgomery ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Mitochondrial Gene ◽  
Nuclear Genes ◽  
Gene Products ◽  
Alternative Pathways ◽  
Peripheral Stalk ◽  
Membrane Bound ◽  
Membrane Components ◽  
Subunit B ◽  
Cytoplasmic Ribosomes

The adenosine triphosphate (ATP) synthase in human mitochondria is a membrane bound assembly of 29 proteins of 18 kinds organized into F1-catalytic, peripheral stalk (PS), and c8-rotor ring modules. All but two membrane components are encoded in nuclear genes, synthesized on cytoplasmic ribosomes, imported into the mitochondrial matrix, and assembled into the complex with the mitochondrial gene products ATP6 and ATP8. Intermediate vestigial ATPase complexes formed by disruption of nuclear genes for individual subunits provide a description of how the various domains are introduced into the enzyme. From this approach, it is evident that three alternative pathways operate to introduce the PS module (including associated membrane subunits e, f, and g). In one pathway, the PS is built up by addition to the core subunit b of membrane subunits e and g together, followed by membrane subunit f. Then this b-e-g-f complex is bound to the preformed F1-c8module by subunits OSCP and F6. The final component of the PS, subunit d, is added subsequently to form a key intermediate that accepts the two mitochondrially encoded subunits. In another route to this key intermediate, first e and g together and then f are added to a preformed F1-c8-OSCP-F6-b-d complex. A third route involves the addition of the c8-ring module to the complete F1-PS complex. The key intermediate then accepts the two mitochondrially encoded subunits, stabilized by the addition of subunit j, leading to an ATP synthase complex that is coupled to the proton motive force and capable of making ATP.

scholarly journals Assembly of the membrane domain of ATP synthase in human mitochondria

2018 ◽  
Vol 115 (12) ◽  
pp. 2988-2993 ◽  
Author(s):  
Jiuya He ◽  
Holly C. Ford ◽  
Joe Carroll ◽  
Corsten Douglas ◽  
Evvia Gonzales ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Atp Synthesis ◽  
Membrane Domain ◽  
Atpase Inhibitor ◽  
Peripheral Stalk ◽  
Mitochondrial Ribosomes ◽  
Human Genes ◽  
The Matrix ◽  
Membrane Bound ◽  
Membrane Components

The ATP synthase in human mitochondria is a membrane-bound assembly of 29 proteins of 18 kinds. All but two membrane components are encoded in nuclear genes, synthesized on cytoplasmic ribosomes, and imported into the matrix of the organelle, where they are assembled into the complex with ATP6 and ATP8, the products of overlapping genes in mitochondrial DNA. Disruption of individual human genes for the nuclear-encoded subunits in the membrane portion of the enzyme leads to the formation of intermediate vestigial ATPase complexes that provide a description of the pathway of assembly of the membrane domain. The key intermediate complex consists of the F1-c8 complex inhibited by the ATPase inhibitor protein IF1 and attached to the peripheral stalk, with subunits e, f, and g associated with the membrane domain of the peripheral stalk. This intermediate provides the template for insertion of ATP6 and ATP8, which are synthesized on mitochondrial ribosomes. Their association with the complex is stabilized by addition of the 6.8 proteolipid, and the complex is coupled to ATP synthesis at this point. A structure of the dimeric yeast Fo membrane domain is consistent with this model of assembly. The human 6.8 proteolipid (yeast j subunit) locks ATP6 and ATP8 into the membrane assembly, and the monomeric complexes then dimerize via interactions between ATP6 subunits and between 6.8 proteolipids (j subunits). The dimers are linked together back-to-face by DAPIT (diabetes-associated protein in insulin-sensitive tissue; yeast subunit k), forming long oligomers along the edges of the cristae.

scholarly journals Permeability transition in human mitochondria persists in the absence of peripheral stalk subunits of ATP synthase

2017 ◽  
Vol 114 (34) ◽  
pp. 9086-9091 ◽  
Author(s):  
Jiuya He ◽  
Joe Carroll ◽  
Shujing Ding ◽  
Ian M. Fearnley ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Catalytic Domain ◽  
Atp Synthesis ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Helical Structure ◽  
Cyclophilin D ◽  
Membrane Domain ◽  
Peripheral Stalk ◽  
Subunit B

The opening of a nonspecific channel, known as the permeability transition pore (PTP), in the inner membranes of mitochondria can be triggered by calcium ions, leading to swelling of the organelle, disruption of the inner membrane and ATP synthesis, and cell death. Pore opening can be inhibited by cyclosporin A mediated via cyclophilin D. It has been proposed that the pore is associated with the dimeric ATP synthase and the oligomycin sensitivity conferral protein (OSCP), a component of the enzyme’s peripheral stalk, provides the site at which cyclophilin D interacts. Subunit b contributes a central α-helical structure to the peripheral stalk, extending from near the top of the enzyme’s catalytic domain and crossing the membrane domain of the enzyme via two α-helices. We investigated the possible involvement of the subunit b and the OSCP in the PTP by generating clonal cells, HAP1-Δb and HAP1-ΔOSCP, lacking the membrane domain of subunit b or the OSCP, respectively, in which the corresponding genes, ATP5F1 and ATP5O, had been disrupted. Both cell lines preserve the characteristic properties of the PTP; therefore, the membrane domain of subunit b does not contribute to the PTP, and the OSCP does not provide the site of interaction with cyclophilin D. The membrane subunits ATP6, ATP8, and subunit c have been eliminated previously from possible participation in the PTP; thus, the only subunits of ATP synthase that could participate in pore formation are e, f, g, diabetes-associated protein in insulin-sensitive tissues (DAPIT), and the 6.8-kDa proteolipid.

Structural aspects of proton-pumping ATPases

1990 ◽  
Vol 326 (1236) ◽  
pp. 367-378 ◽  
Keyword(s):  
Amino Acids ◽  
Atp Synthase ◽  
Nuclear Gene ◽  
Potential Gradient ◽  
Proton Pumping ◽  
Proton Channel ◽  
Globular Domain ◽  
Globular Structure ◽  
Membrane Bound ◽  
Membrane Components

ATP synthase is found in bacteria, chloroplasts and mitochondria. The simplest known example of such an enzyme is that in the eubacterium Escherichia coli ; it is a membrane-bound assembly of eight different polypeptides assembled with a stoichiometry of x 3 β 3 γ 1 δ 1 ε 1 a 1 b 2 c 10-12 . The first five of these constitute a globular structure, Fj-ATPase, which is bound to an instrinsic membrane domain, F0, an assembly of the three remaining subunits. ATP synthases driven by photosynthesis are slightly more complex. In chloroplasts, and probably in photosynthetic bacteria, they have nine subunits, all homologues of the components of the E. coli enzyme; the additional subunit is a duplicated and diverged relation of subunit b. The mammalian mitochondrial enzyme is more complex. It contains 14 different polypetides, of which 13 have been characterized. Two membrane components, a (or ATPase-6) and A6L, are encoded in the mitochondrial genome in overlapping genes and the remaining subunits are nuclear gene products that are translated on cytoplasmic ribosomes and then imported into the organelle. The sequences of the proteins of ATP-synthase have provided information about amino acids that are important for its function. For example, amino acids contributing to nucleotide binding sites have been identified. Also, they provide the basis of models of secondary structure of membrane components that constitute the transmembrane proton channel. An understanding of the coupling of the transmembrane potential gradient for protons, A/%+, to ATP synthesis will probably require the determination of the structure of the entire membrane bound complex. Crystals have been obtained of the globular domain, Fj-ATPase. They diffract to a resolution of 3^4 A f and data collection is in progress. As a preliminary step towards crystallization of the entire complex, we have purified it from bovine mitochondria and reconstituted it into phospholipid vesicles.

scholarly journals TMEM70 and TMEM242 help to assemble the rotor ring of human ATP synthase and interact with assembly factors for complex I

2021 ◽  
Vol 118 (13) ◽  
pp. e2100558118
Author(s):  
Joe Carroll ◽  
Jiuya He ◽  
Shujing Ding ◽  
Ian M. Fearnley ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Complex I ◽  
Transmembrane Protein ◽  
Mitochondrial Gene ◽  
Nuclear Gene ◽  
Gene Products ◽  
Mitochondrial Atp Synthase ◽  
Complex I Assembly ◽  
The Impact ◽  
Enzyme Complexes

Human mitochondrial ATP synthase is a molecular machine with a rotary action bound in the inner organellar membranes. Turning of the rotor, driven by a proton motive force, provides energy to make ATP from ADP and phosphate. Among the 29 component proteins of 18 kinds, ATP6 and ATP8 are mitochondrial gene products, and the rest are nuclear gene products that are imported into the organelle. The ATP synthase is assembled from them via intermediate modules representing the main structural elements of the enzyme. One such module is the c8-ring, which provides the membrane sector of the enzyme’s rotor, and its assembly is influenced by another transmembrane (TMEM) protein, TMEM70. We have shown that subunit c interacts with TMEM70 and another hitherto unidentified mitochondrial transmembrane protein, TMEM242. Deletion of TMEM242, similar to deletion of TMEM70, affects but does not completely eliminate the assembly of ATP synthase, and to a lesser degree the assembly of respiratory enzyme complexes I, III, and IV. Deletion of TMEM70 and TMEM242 together prevents assembly of ATP synthase and the impact on complex I is enhanced. Removal of TMEM242, but not of TMEM70, also affects the introduction of subunits ATP6, ATP8, j, and k into the enzyme. TMEM70 and TMEM242 interact with the mitochondrial complex I assembly (the MCIA) complex that supports assembly of the membrane arm of complex I. The interactions of TMEM70 and TMEM242 with MCIA could be part of either the assembly of ATP synthase and complex I or the regulation of their levels.

scholarly journals Characterisation of a highly diverged mitochondrial ATP synthase peripheral stalk subunit b in Trypanosoma brucei

2021 ◽  
Author(s):  
Caroline E. Dewar ◽  
Silke Oeljeklaus ◽  
Bettina Warscheid ◽  
André Schneider
Keyword(s):  
Cell Cycle ◽  
Membrane Potential ◽  
Trypanosoma Brucei ◽  
Atp Synthase ◽  
Mitochondrial Protein ◽  
Normal Growth ◽  
Native Page ◽  
Peripheral Stalk ◽  
Mitochondrial Atp Synthase ◽  
Subunit B

The mitochondrial F1Fo ATP synthase of Trypanosoma brucei has been studied in detail. Whereas its F1 moiety is relatively highly conserved in structure and composition, the same is not the case for the Fo part and the peripheral stalk. A core subunit of the latter, the normally conserved subunit b, could not be identified in trypanosomes suggesting that it might be absent. Here we have identified a 17 kDa mitochondrial protein of the inner membrane that is essential for normal growth, efficient oxidative phosphorylation and membrane potential maintenance. Pulldown experiments and native PAGE analysis indicate that the protein is associated with the F1Fo ATP synthase. Its ablation reduces the levels of Fo subunits, but not those of F1, and disturbs the cell cycle. HHpred analysis showed that the protein has structural similarities to subunit b of other species, indicating that the Fo part of the trypanosomal ATP synthase does contain a highly diverged subunit b. Thus, the Fo part of the trypanosomal ATPase synthase may be more widely conserved than initially thought.

scholarly journals Persistence of the permeability transition pore in human mitochondria devoid of an assembled ATP synthase

2019 ◽  
Vol 116 (26) ◽  
pp. 12816-12821 ◽  
Author(s):  
Joe Carroll ◽  
Jiuya He ◽  
Shujing Ding ◽  
Ian M. Fearnley ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Catalytic Domain ◽  
Total Concentration ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Cyclophilin D ◽  
Peripheral Stalk ◽  
Associated Proteins ◽  
Pore Opening ◽  
Membrane Bound

The opening of the permeability transition pore, a nonspecific channel in inner mitochondrial membranes, is triggered by an elevated total concentration of calcium ions in the mitochondrial matrix, leading to disruption of the inner membrane and necrotic cell death. Cyclosporin A inhibits pore opening by binding to cyclophilin D, which interacts with the pore. It has been proposed that the pore is associated with the ATP synthase complex. Previously, we confirmed an earlier observation that the pore survives in cells lacking membrane subunits ATP6 and ATP8 of ATP synthase, and in other cells lacking the enzyme’s c8rotor ring or, separately, its peripheral stalk subunits b and oligomycin sensitive conferral protein. Here, we investigated whether the pore is associated with the remaining membrane subunits of the enzyme. Individual deletion of subunits e, f, g, and 6.8-kDa proteolipid disrupts dimerization of the complex, and deletion of DAPIT (diabetes-associated protein in insulin sensitive tissue) possibly influences oligomerization of dimers, but removal of each subunit had no effect on the pore. Also, we removed together the enzyme’s membrane bound c8ring and the δ-subunit from the catalytic domain. The resulting cells assemble only a subcomplex derived from the peripheral stalk and membrane-associated proteins. Despite diminished levels of respiratory complexes, these cells generate a membrane potential to support uptake of calcium into the mitochondria, leading to pore opening, and retention of its characteristic properties. It is most unlikely that the ATP synthase, dimer or monomer, or any component, provides the permeability transition pore.

scholarly journals Regulation by nuclear genes of the mitochondrial synthesis of subunits 6 and 8 of the ATP synthase of Saccharomyces cerevisiae.

1992 ◽  
Vol 267 (4) ◽  
pp. 2467-2473
Author(s):  
P P Pelissier ◽  
N M Camougrand ◽  
S T Manon ◽  
G M Velours ◽  
M G Guerin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Atp Synthase ◽  
Nuclear Genes

Dual Mutations Reveal Interactions Between Components of Oxidative Phosphorylation in Kluyveromyces lactis

Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 929-938
Author(s):  
G D Clark-Walker ◽  
X J Chen
Keyword(s):  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Atp Synthase ◽  
Kluyveromyces Lactis ◽  
Mitochondrial Protein ◽  
Proton Pumping ◽  
Nuclear Genes ◽  
Suppressor Activity ◽  
Inner Membrane ◽  
Atp Production

Abstract Loss of mtDNA or mitochondrial protein synthesis cannot be tolerated by wild-type Kluyveromyces lactis. The mitochondrial function responsible for ρ0-lethality has been identified by disruption of nuclear genes encoding electron transport and F0-ATP synthase components of oxidative phosphorylation. Sporulation of diploid strains heterozygous for disruptions in genes for the two components of oxidative phosphorylation results in the formation of nonviable spores inferred to contain both disruptions. Lethality of spores is thought to result from absence of a transmembrane potential, ΔΨ, across the mitochondrial inner membrane due to lack of proton pumping by the electron transport chain or reversal of F1F0-ATP synthase. Synergistic lethality, caused by disruption of nuclear genes, or ρ0-lethality can be suppressed by the atp2.1 mutation in the β-subunit of F1-ATPase. Suppression is viewed as occurring by an increased hydrolysis of ATP by mutant F1, allowing sufficient electrogenic exchange by the translocase of ADP in the matrix for ATP in the cytosol to maintain ΔΨ. In addition, lethality of haploid strains with a disruption of AAC encoding the ADP/ATP translocase can be suppressed by atp2.1. In this case suppression is considered to occur by mutant F1 acting in the forward direction to partially uncouple ATP production, thereby stimulating respiration and relieving detrimental hyperpolarization of the inner membrane. Participation of the ADP/ATP translocase in suppression of ρ0-lethality is supported by the observation that disruption of AAC abolishes suppressor activity of atp2.1.

Role of nuclear genes in expression of a mitochondrial tRNA gene in Saccharomyces cerevisiae

1983 ◽  
Vol 3 (3) ◽  
pp. 371-379
Author(s):  
M Wesolowski ◽  
C Palleschi ◽  
L Frontali ◽  
H Fukuhara
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Trna Gene ◽  
Mitochondrial Gene ◽  
Nuclear Genes ◽  
Yeast Mitochondria ◽  
Mitochondrial Trna ◽  
Genetic Crosses ◽  
Mitochondrial Trna Gene

In yeast mitochondria, most of the isoaccepting species of tyrosyl tRNA are coded by a mitochondrial gene, tyrA. A particular isoaccepting species is coded by a second mitochondrial gene, tyrB. This gene is not expressed in certain strains of yeast which show no deficient phenotype. Genetic crosses between strains expressing or not expressing the tyrB gene demonstrate that expression is controlled by specific nuclear genes and that a mutation of the tyrA gene can be bypassed when the tyrB gene is operative.

Sign in / Sign up

Export Citation Format

Share Document