1
|
Xie D, Zheng J, Sun Y, Li X, Ren S. Effects of Ca 2+ signal on the activities of key enzymes and expression of related genes in yeast ethanol metabolism and mitochondrial function during high sugar fermentation. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:5077-5088. [PMID: 38284794 DOI: 10.1002/jsfa.13341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/20/2024] [Accepted: 01/24/2024] [Indexed: 01/30/2024]
Abstract
BACKGROUND During high sugar fermentation, yeast is mainly affected by high sugar stress in the early stage. It becomes jointly affected by high sugar and ethanol stress as ethanol accumulates during fermentation. Ca2+, as the second messenger of the cell, mediates various metabolic processes. In this study, the effects of the Ca2+ signal on the activities of key enzymes, expression of related genes of ethanol metabolism, and mitochondrial function were investigated. RESULTS The results showed a significant increase in the activities of enzymes related to ethanol metabolism in yeast cells under a high sugar environment. Ca2+ significantly promoted the activities of enzymes related to mitochondrial respiratory metabolism and regulated the carbon flow between ethanol metabolism and the tricarboxylic acid cycle. The high sugar environment affected the expression of genes related to carbon metabolism, while the addition of Ca2+ stabilized the expression of related genes. CONCLUSION Ca2+ signal participated in ethanol and mitochondrial metabolism and regulated the key enzymes and related gene expression to enhance the resistance of yeast to stress during high sugar fermentation. © 2024 Society of Chemical Industry.
Collapse
Affiliation(s)
- Dongdong Xie
- Food Engineering Technology Research Center/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Jiaxin Zheng
- Food Engineering Technology Research Center/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Yingqi Sun
- Food Engineering Technology Research Center/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Xing Li
- Food Engineering Technology Research Center/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Shuncheng Ren
- Food Engineering Technology Research Center/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| |
Collapse
|
2
|
Kremer LS, Rehling P. Coordinating mitochondrial translation with assembly of the OXPHOS complexes. Hum Mol Genet 2024; 33:R47-R52. [PMID: 38779773 PMCID: PMC11112383 DOI: 10.1093/hmg/ddae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/31/2024] [Accepted: 02/09/2024] [Indexed: 05/25/2024] Open
Abstract
The mitochondrial oxidative phosphorylation (OXPHOS) system produces the majority of energy required by cells. Given the mitochondrion's endosymbiotic origin, the OXPHOS machinery is still under dual genetic control where most OXPHOS subunits are encoded by the nuclear DNA and imported into mitochondria, while a small subset is encoded on the mitochondrion's own genome, the mitochondrial DNA (mtDNA). The nuclear and mtDNA encoded subunits must be expressed and assembled in a highly orchestrated fashion to form a functional OXPHOS system and meanwhile prevent the generation of any harmful assembly intermediates. While several mechanisms have evolved in eukaryotes to achieve such a coordinated expression, this review will focus on how the translation of mtDNA encoded OXPHOS subunits is tailored to OXPHOS assembly.
Collapse
Affiliation(s)
- Laura S Kremer
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, Göttingen 37073, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Robert-Koch-Str. 40, Göttingen 37075, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology, Translational Neuroinflammation and Automated Microscopy, Robert-Koch-Str. 40, Göttingen 37075, Germany
- Max Planck Institute for Multidisciplinary Science, Am Faßberg 11, Göttingen 37077, Germany
| |
Collapse
|
3
|
Eldeeb MH, Camacho Lopez LJ, Fontanesi F. Mitochondrial respiratory supercomplexes of the yeast Saccharomyces cerevisiae. IUBMB Life 2024. [PMID: 38529880 DOI: 10.1002/iub.2817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/28/2024] [Indexed: 03/27/2024]
Abstract
The functional and structural relationship among the individual components of the mitochondrial respiratory chain constitutes a central aspect of our understanding of aerobic catabolism. This interplay has been a subject of intense debate for over 50 years. It is well established that individual respiratory enzymes associate into higher-order structures known as respiratory supercomplexes, which represent the evolutionarily conserved organizing principle of the mitochondrial respiratory chain. In the yeast Saccharomyces cerevisiae, supercomplexes are formed by a complex III homodimer flanked by one or two complex IV monomers, and their high-resolution structures have been recently elucidated. Despite the wealth of structural information, several proposed supercomplex functions remain speculative and our understanding of their physiological relevance is still limited. Recent advances in the field were made possible by the construction of yeast strains where the association of complex III and IV into supercomplexes is impeded, leading to diminished respiratory capacity and compromised cellular competitive fitness. Here, we discuss the experimental evidence and hypotheses relative to the functional roles of yeast respiratory supercomplexes. Moreover, we review the current models of yeast complex III and IV assembly in the context of supercomplex formation and highlight the data scattered throughout the literature suggesting the existence of cross talk between their biogenetic processes.
Collapse
Affiliation(s)
- Mazzen H Eldeeb
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Lizeth J Camacho Lopez
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| |
Collapse
|
4
|
Xie D, Sun Y, Li X, Ren S. Effect of calcium levels on structure and function of mitochondria in yeast under high glucose fermentation. FOOD SCI TECHNOL INT 2023:10820132231170409. [PMID: 37089015 DOI: 10.1177/10820132231170409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
In this study, the effects of calcium levels on structure and function of mitochondria under high glucose environment were studied. In the high glucose environment, yeast growth capacity was inhibited, and intracellular reactive oxygen species (ROS) content was increased from 6 h to 12 h, while ROS content was reduced in group with 1 × 10-1 and 1 g/L CaCl2 level from 24 h to 36 h. Exogenous calcium addition had a significant effect on the elevation of intracellular Ca2+ and cytochrome C content in yeast from 6 h to 12 h; mitochondrial membrane potential decreased with the increase of CaCl2 level under high glucose levels. Mitochondrial swelling of yeast was influenced by high glucose levels and showed a regulatory dynamic change by Ca2+ levels. Isocitrate dehydrogenase activity increased in 1 × 10-3 g/L CaCl2 level from 6 h to 12 h, α-ketoglutarate dehydrogenase activity increased with an increase in CaCl2 level from 6 h to 24 h. Calcium affected the structure and function of mitochondria by regulating the intracellular signal, enzymes in tricarboxylic acid cycle, and cytochrome system of yeast under high glucose stress.
Collapse
Affiliation(s)
- Dongdong Xie
- National Engineering Laboratory/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Yingqi Sun
- National Engineering Laboratory/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Xing Li
- National Engineering Laboratory/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Shuncheng Ren
- National Engineering Laboratory/Key Laboratory of Henan Province, School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| |
Collapse
|
5
|
Cryo-EM structure and function of S. pombe complex IV with bound respiratory supercomplex factor. Commun Chem 2023; 6:32. [PMID: 36797353 PMCID: PMC9935853 DOI: 10.1038/s42004-023-00827-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Fission yeast Schizosaccharomyces pombe serves as model organism for studying higher eukaryotes. We combined the use of cryo-EM and spectroscopy to investigate the structure and function of affinity purified respiratory complex IV (CIV) from S. pombe. The reaction sequence of the reduced enzyme with O2 proceeds over a time scale of µs-ms, similar to that of the mammalian CIV. The cryo-EM structure of CIV revealed eleven subunits as well as a bound hypoxia-induced gene 1 (Hig1) domain of respiratory supercomplex factor 2 (Rcf2). These results suggest that binding of Rcf2 does not require the presence of a CIII-CIV supercomplex, i.e. Rcf2 is a component of CIV. An AlphaFold-Multimer model suggests that the Hig1 domains of both Rcf1 and Rcf2 bind at the same site of CIV suggesting that their binding is mutually exclusive. Furthermore, the differential functional effect of Rcf1 or Rcf2 is presumably caused by interactions of CIV with their different non-Hig1 domain parts.
Collapse
|
6
|
Fry MY, Saladi SM, Cunha A, Clemons WM. Sequence-based features that are determinant for tail-anchored membrane protein sorting in eukaryotes. Traffic 2021; 22:306-318. [PMID: 34288289 PMCID: PMC8380732 DOI: 10.1111/tra.12809] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/15/2021] [Accepted: 07/18/2021] [Indexed: 11/29/2022]
Abstract
The correct targeting and insertion of tail-anchored (TA) integral membrane proteins is critical for cellular homeostasis. TA proteins are defined by a hydrophobic transmembrane domain (TMD) at their C-terminus and are targeted to either the ER or mitochondria. Derived from experimental measurements of a few TA proteins, there has been little examination of the TMD features that determine localization. As a result, the localization of many TA proteins are misclassified by the simple heuristic of overall hydrophobicity. Because ER-directed TMDs favor arrangement of hydrophobic residues to one side, we sought to explore the role of geometric hydrophobic properties. By curating TA proteins with experimentally determined localizations and assessing hypotheses for recognition, we bioinformatically and experimentally verify that a hydrophobic face is the most accurate singular metric for separating ER and mitochondria-destined yeast TA proteins. A metric focusing on an 11 residue segment of the TMD performs well when classifying human TA proteins. The most inclusive predictor uses both hydrophobicity and C-terminal charge in tandem. This work provides context for previous observations and opens the door for more detailed mechanistic experiments to determine the molecular factors driving this recognition.
Collapse
Affiliation(s)
- Michelle Y. Fry
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Shyam M. Saladi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Alexandre Cunha
- Division of Biology and Biological Engineering, Center for Advanced Methods in Biological Image Analysis, Beckman Institute, Pasadena, California, USA
| | - William M. Clemons
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| |
Collapse
|
7
|
Brzezinski P, Moe A, Ädelroth P. Structure and Mechanism of Respiratory III-IV Supercomplexes in Bioenergetic Membranes. Chem Rev 2021; 121:9644-9673. [PMID: 34184881 PMCID: PMC8361435 DOI: 10.1021/acs.chemrev.1c00140] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Indexed: 12/12/2022]
Abstract
In the final steps of energy conservation in aerobic organisms, free energy from electron transfer through the respiratory chain is transduced into a proton electrochemical gradient across a membrane. In mitochondria and many bacteria, reduction of the dioxygen electron acceptor is catalyzed by cytochrome c oxidase (complex IV), which receives electrons from cytochrome bc1 (complex III), via membrane-bound or water-soluble cytochrome c. These complexes function independently, but in many organisms they associate to form supercomplexes. Here, we review the structural features and the functional significance of the nonobligate III2IV1/2 Saccharomyces cerevisiae mitochondrial supercomplex as well as the obligate III2IV2 supercomplex from actinobacteria. The analysis is centered around the Q-cycle of complex III, proton uptake by CytcO, as well as mechanistic and structural solutions to the electronic link between complexes III and IV.
Collapse
Affiliation(s)
- Peter Brzezinski
- Department of Biochemistry and Biophysics,
The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Agnes Moe
- Department of Biochemistry and Biophysics,
The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics,
The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
8
|
Franco LVR, Su CH, Tzagoloff A. Modular assembly of yeast mitochondrial ATP synthase and cytochrome oxidase. Biol Chem 2021; 401:835-853. [PMID: 32142477 DOI: 10.1515/hsz-2020-0112] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/24/2020] [Indexed: 12/27/2022]
Abstract
The respiratory pathway of mitochondria is composed of four electron transfer complexes and the ATP synthase. In this article, we review evidence from studies of Saccharomyces cerevisiae that both ATP synthase and cytochrome oxidase (COX) are assembled from independent modules that correspond to structurally and functionally identifiable components of each complex. Biogenesis of the respiratory chain requires a coordinate and balanced expression of gene products that become partner subunits of the same complex, but are encoded in the two physically separated genomes. Current evidence indicates that synthesis of two key mitochondrial encoded subunits of ATP synthase is regulated by the F1 module. Expression of COX1 that codes for a subunit of the COX catalytic core is also regulated by a mechanism that restricts synthesis of this subunit to the availability of a nuclear-encoded translational activator. The respiratory chain must maintain a fixed stoichiometry of the component enzyme complexes during cell growth. We propose that high-molecular-weight complexes composed of Cox6, a subunit of COX, and of the Atp9 subunit of ATP synthase play a key role in establishing the ratio of the two complexes during their assembly.
Collapse
Affiliation(s)
- Leticia Veloso Ribeiro Franco
- Department of Biological Sciences, Columbia University, New York City, NY 10027, USA.,Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, 05508-000, Brasil
| | - Chen Hsien Su
- Department of Biological Sciences, Columbia University, New York City, NY 10027, USA
| | - Alexander Tzagoloff
- Department of Biological Sciences, Columbia University, New York City, NY 10027, USA
| |
Collapse
|
9
|
Linden A, Deckers M, Parfentev I, Pflanz R, Homberg B, Neumann P, Ficner R, Rehling P, Urlaub H. A Cross-linking Mass Spectrometry Approach Defines Protein Interactions in Yeast Mitochondria. Mol Cell Proteomics 2020; 19:1161-1178. [PMID: 32332106 PMCID: PMC7338081 DOI: 10.1074/mcp.ra120.002028] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/24/2020] [Indexed: 12/13/2022] Open
Abstract
Protein cross-linking and the analysis of cross-linked peptides by mass spectrometry is currently receiving much attention. Not only is this approach applied to isolated complexes to provide information about spatial arrangements of proteins, but it is also increasingly applied to entire cells and their organelles. As in quantitative proteomics, the application of isotopic labeling further makes it possible to monitor quantitative changes in the protein-protein interactions between different states of a system. Here, we cross-linked mitochondria from Saccharomyces cerevisiae grown on either glycerol- or glucose-containing medium to monitor protein-protein interactions under non-fermentative and fermentative conditions. We investigated qualitatively the protein-protein interactions of the 400 most abundant proteins applying stringent data-filtering criteria, i.e. a minimum of two cross-linked peptide spectrum matches and a cut-off in the spectrum scoring of the used search engine. The cross-linker BS3 proved to be equally suited for connecting proteins in all compartments of mitochondria when compared with its water-insoluble but membrane-permeable derivative DSS. We also applied quantitative cross-linking to mitochondria of both the growth conditions using stable-isotope labeled BS3. Significant differences of cross-linked proteins under glycerol and glucose conditions were detected, however, mainly because of the different copy numbers of these proteins in mitochondria under both the conditions. Results obtained from the glycerol condition indicate that the internal NADH:ubiquinone oxidoreductase Ndi1 is part of an electron transport chain supercomplex. We have also detected several hitherto uncharacterized proteins and identified their interaction partners. Among those, Min8 was found to be associated with cytochrome c oxidase. BN-PAGE analyses of min8Δ mitochondria suggest that Min8 promotes the incorporation of Cox12 into cytochrome c oxidase.
Collapse
Affiliation(s)
- Andreas Linden
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Markus Deckers
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Iwan Parfentev
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ralf Pflanz
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Bettina Homberg
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Piotr Neumann
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, Göttingen, Germany
| | - Ralf Ficner
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany; Department of Molecular Structural Biology, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, Göttingen, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany; Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany.
| |
Collapse
|
10
|
Björck ML, Vilhjálmsdóttir J, Hartley AM, Meunier B, Näsvik Öjemyr L, Maréchal A, Brzezinski P. Proton-transfer pathways in the mitochondrial S. cerevisiae cytochrome c oxidase. Sci Rep 2019; 9:20207. [PMID: 31882860 PMCID: PMC6934443 DOI: 10.1038/s41598-019-56648-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 12/16/2019] [Indexed: 02/04/2023] Open
Abstract
In cytochrome c oxidase (CytcO) reduction of O2 to water is linked to uptake of eight protons from the negative side of the membrane: four are substrate protons used to form water and four are pumped across the membrane. In bacterial oxidases, the substrate protons are taken up through the K and the D proton pathways, while the pumped protons are transferred through the D pathway. On the basis of studies with CytcO isolated from bovine heart mitochondria, it was suggested that in mitochondrial CytcOs the pumped protons are transferred though a third proton pathway, the H pathway, rather than through the D pathway. Here, we studied these reactions in S. cerevisiae CytcO, which serves as a model of the mammalian counterpart. We analyzed the effect of mutations in the D (Asn99Asp and Ile67Asn) and H pathways (Ser382Ala and Ser458Ala) and investigated the kinetics of electron and proton transfer during the reaction of the reduced CytcO with O2. No effects were observed with the H pathway variants while in the D pathway variants the functional effects were similar to those observed with the R. sphaeroides CytcO. The data indicate that the S. cerevisiae CytcO uses the D pathway for proton uptake and presumably also for proton pumping.
Collapse
Affiliation(s)
- Markus L Björck
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Jóhanna Vilhjálmsdóttir
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Andrew M Hartley
- Department of Biological Sciences, Birkbeck University of London, Malet Street, London, WC1E 7HX, UK
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (12BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Linda Näsvik Öjemyr
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Amandine Maréchal
- Department of Biological Sciences, Birkbeck University of London, Malet Street, London, WC1E 7HX, UK. .,Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91, Stockholm, Sweden.
| |
Collapse
|
11
|
Bausewein T, Nussberger S, Kühlbrandt W. Cryo-EM structure of Neurospora crassa respiratory complex IV. IUCRJ 2019; 6:773-780. [PMID: 31316820 PMCID: PMC6608615 DOI: 10.1107/s2052252519007486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/23/2019] [Indexed: 05/13/2023]
Abstract
In fungi, the mitochondrial respiratory chain complexes (complexes I-IV) are responsible for oxidative phosphorylation, as in higher eukaryotes. Cryo-EM was used to identify a 200 kDa membrane protein from Neurospora crassa in lipid nanodiscs as cytochrome c oxidase (complex IV) and its structure was determined at 5.5 Å resolution. The map closely resembles the cryo-EM structure of complex IV from Saccharomyces cerevisiae. Its ten subunits are conserved in S. cerevisiae and Bos taurus, but other transmembrane subunits are missing. The different structure of the Cox5a subunit is typical for fungal complex IV and may affect the interaction with complex III in a respiratory supercomplex. Additional density was found between the matrix domains of the Cox4 and Cox5a subunits that appears to be specific to N. crassa.
Collapse
Affiliation(s)
- Thomas Bausewein
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| | - Stephan Nussberger
- Abteilung Biophysik, Institut für Biomaterialien und biomolekulare Systeme, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| |
Collapse
|
12
|
Rathore S, Berndtsson J, Marin-Buera L, Conrad J, Carroni M, Brzezinski P, Ott M. Cryo-EM structure of the yeast respiratory supercomplex. Nat Struct Mol Biol 2018; 26:50-57. [PMID: 30598556 DOI: 10.1038/s41594-018-0169-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/14/2018] [Indexed: 01/08/2023]
Abstract
Respiratory chain complexes execute energy conversion by connecting electron transport with proton translocation over the inner mitochondrial membrane to fuel ATP synthesis. Notably, these complexes form multi-enzyme assemblies known as respiratory supercomplexes. Here we used single-particle cryo-EM to determine the structures of the yeast mitochondrial respiratory supercomplexes III2IV and III2IV2, at 3.2-Å and 3.5-Å resolutions, respectively. We revealed the overall architecture of the supercomplex, which deviates from the previously determined assemblies in mammals; obtained a near-atomic structure of the yeast complex IV; and identified the protein-protein and protein-lipid interactions implicated in supercomplex formation. Take together, our results demonstrate convergent evolution of supercomplexes in mitochondria that, while building similar assemblies, results in substantially different arrangements and structural solutions to support energy conversion.
Collapse
Affiliation(s)
- Sorbhi Rathore
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Jens Berndtsson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Lorena Marin-Buera
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Julian Conrad
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Marta Carroni
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
13
|
Structure of yeast cytochrome c oxidase in a supercomplex with cytochrome bc 1. Nat Struct Mol Biol 2018; 26:78-83. [PMID: 30598554 PMCID: PMC6330080 DOI: 10.1038/s41594-018-0172-z] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 11/21/2018] [Indexed: 01/24/2023]
Abstract
Cytochrome c oxidase (complex IV, CIV) is known in mammals to exist independently or in association with other respiratory proteins to form supercomplexes (SCs). In Saccharomyces cerevisiae, CIV is found solely in an SC with cytochrome bc1 (complex III, CIII). Here, we present the cryogenic electron microscopy (cryo-EM) structure of S. cerevisiae CIV in a III2IV2 SC at 3.3 Å resolution. While overall similarity to mammalian homologs is high, we found notable differences in the supernumerary subunits Cox26 and Cox13; the latter exhibits a unique arrangement that precludes CIV dimerization as seen in bovine. A conformational shift in the matrix domain of Cox5A-involved in allosteric inhibition by ATP-may arise from its association with CIII. The CIII-CIV arrangement highlights a conserved interaction interface of CIII, albeit one occupied by complex I in mammalian respirasomes. We discuss our findings in the context of the potential impact of SC formation on CIV regulation.
Collapse
|
14
|
Franco LVR, Su CH, McStay GP, Yu GJ, Tzagoloff A. Cox2p of yeast cytochrome oxidase assembles as a stand-alone subunit with the Cox1p and Cox3p modules. J Biol Chem 2018; 293:16899-16911. [PMID: 30224355 DOI: 10.1074/jbc.ra118.004138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 09/11/2018] [Indexed: 11/06/2022] Open
Abstract
Cytochrome oxidase (COX) is a hetero-oligomeric complex of the mitochondrial inner membrane that reduces molecular oxygen to water, a reaction coupled to proton transfer from the mitochondrial matrix to the intermembrane space. In the yeast Saccharomyces cerevisiae, COX is composed of 11-13 different polypeptide subunits. Here, using pulse labeling of mitochondrial gene products in isolated yeast mitochondria, combined with purification of tagged COX subunits and ancillary factors, we studied the Cox2p assembly intermediates. Analysis of radiolabeled Cox2p obtained in pulldown assays by native gel electrophoresis revealed the existence of several assembly intermediates, the largest of which had an estimated mass of 450-550 kDa. None of the other known subunits of COX were present in these Cox2p intermediates. This was also true for the several ancillary factors having still undefined functions in COX assembly. In agreement with earlier evidence, Cox18p and Cox20p, previously shown to be involved in processing and in membrane insertion of the Cox2p precursor, were found to be associated with the two largest Cox2p intermediates. A small fraction of the Cox2p module contained Sco1p and Coa6p, which have been implicated in metalation of the binuclear copper site on this subunit. Our results indicate that following its insertion into the mitochondrial inner membrane, Cox2p assembles as a stand-alone protein with the compositionally more complex Cox1p and Cox3p modules.
Collapse
Affiliation(s)
- Leticia Veloso R Franco
- From the Department of Biological Sciences, Columbia University, New York, New York 10027 and
| | - Chen-Hsien Su
- From the Department of Biological Sciences, Columbia University, New York, New York 10027 and
| | - Gavin P McStay
- Department of Biological Sciences, Staffordshire University, Stoke-on-Trent, ST4 2DF, United Kingdom
| | - George J Yu
- From the Department of Biological Sciences, Columbia University, New York, New York 10027 and
| | - Alexander Tzagoloff
- From the Department of Biological Sciences, Columbia University, New York, New York 10027 and
| |
Collapse
|
15
|
Herwaldt EJ, Rivett ED, White AJ, Hegg EL. Cox15 interacts with the cytochrome bc 1 dimer within respiratory supercomplexes as well as in the absence of cytochrome c oxidase. J Biol Chem 2018; 293:16426-16439. [PMID: 30181213 DOI: 10.1074/jbc.ra118.002496] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 08/15/2018] [Indexed: 11/06/2022] Open
Abstract
The heme a molecule is an obligatory cofactor in the terminal enzyme complex of the electron transport chain, cytochrome c oxidase. Heme a is synthesized from heme o by a multi-spanning inner membrane protein, heme a synthase (Cox15 in the yeast Saccharomyces cerevisiae). The insertion of heme a is critical for cytochrome c oxidase function and assembly, but this process has not been fully elucidated. To improve our understanding of heme a insertion into cytochrome c oxidase, here we investigated the protein-protein interactions that involve Cox15 in S. cerevisiae In addition to observing Cox15 in homooligomeric complexes, we found that a portion of Cox15 also associates with the mitochondrial respiratory supercomplexes. When supercomplex formation was abolished, as in the case of stalled cytochrome bc 1 or cytochrome c oxidase assembly, Cox15 maintained an interaction with select proteins from both respiratory complexes. In the case of stalled cytochrome bc 1 assembly, Cox15 interacted with the late-assembling cytochrome c oxidase subunit, Cox13. When cytochrome c oxidase assembly was stalled, Cox15 unexpectedly maintained its interaction with the cytochrome bc 1 protein, Cor1. Our results indicate that Cox15 and Cor1 continue to interact in the cytochrome bc 1 dimer even in the absence of supercomplexes or when the supercomplexes are destabilized. These findings reveal that Cox15 not only associates with respiratory supercomplexes, but also interacts with the cytochrome bc 1 dimer even in the absence of cytochrome c oxidase.
Collapse
Affiliation(s)
- Emily J Herwaldt
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Elise D Rivett
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Antoineen J White
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Eric L Hegg
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
16
|
Dannenmaier S, Stiller SB, Morgenstern M, Lübbert P, Oeljeklaus S, Wiedemann N, Warscheid B. Complete Native Stable Isotope Labeling by Amino Acids of Saccharomyces cerevisiae for Global Proteomic Analysis. Anal Chem 2018; 90:10501-10509. [PMID: 30102515 PMCID: PMC6300314 DOI: 10.1021/acs.analchem.8b02557] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Knowledge about the functions of individual proteins on a system-wide level is crucial to fully understand molecular mechanisms underlying cellular processes. A considerable part of the proteome across all organisms is still poorly characterized. Mass spectrometry is an efficient technology for the global study of proteins. One of the most prominent methods for accurate proteome-wide comparative quantification is stable isotope labeling by amino acids in cell culture (SILAC). However, application of SILAC to prototrophic organisms such as Saccharomyces cerevisiae, also known as baker's yeast, is compromised since they are able to synthesize all amino acids on their own. Here, we describe an advanced strategy, termed 2nSILAC, that allows for in vivo labeling of prototrophic baker's yeast using heavy arginine and lysine under fermentable and respiratory growth conditions, making it a suitable tool for the global study of protein functions. This generic 2nSILAC strategy allows for directly using and systematically screening yeast mutant strain collections available to the scientific community. We exemplarily demonstrate its high potential by analyzing the effects of mitochondrial gene deletions in mitochondrial fractions using quantitative mass spectrometry revealing the role of Coi1 for the assembly of cytochrome c oxidase (respiratory chain complex IV).
Collapse
|
17
|
Abstract
Mitochondria are the power stations of the eukaryotic cell, using the energy released by the oxidation of glucose and other sugars to produce ATP. Electrons are transferred from NADH, produced in the citric acid cycle in the mitochondrial matrix, to oxygen by a series of large protein complexes in the inner mitochondrial membrane, which create a transmembrane electrochemical gradient by pumping protons across the membrane. The flow of protons back into the matrix via a proton channel in the ATP synthase leads to conformational changes in the nucleotide binding pockets and the formation of ATP. The three proton pumping complexes of the electron transfer chain are NADH-ubiquinone oxidoreductase or complex I, ubiquinone-cytochrome c oxidoreductase or complex III, and cytochrome c oxidase or complex IV. Succinate dehydrogenase or complex II does not pump protons, but contributes reduced ubiquinone. The structures of complex II, III and IV were determined by x-ray crystallography several decades ago, but complex I and ATP synthase have only recently started to reveal their secrets by advances in x-ray crystallography and cryo-electron microscopy. The complexes I, III and IV occur to a certain extent as supercomplexes in the membrane, the so-called respirasomes. Several hypotheses exist about their function. Recent cryo-electron microscopy structures show the architecture of the respirasome with near-atomic detail. ATP synthase occurs as dimers in the inner mitochondrial membrane, which by their curvature are responsible for the folding of the membrane into cristae and thus for the huge increase in available surface that makes mitochondria the efficient energy plants of the eukaryotic cell.
Collapse
Affiliation(s)
- Joana S Sousa
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Edoardo D'Imprima
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| |
Collapse
|
18
|
Su CH, Tzagoloff A. Cox16 protein is physically associated with Cox1p assembly intermediates and with cytochrome oxidase. J Biol Chem 2017; 292:16277-16283. [PMID: 28821616 DOI: 10.1074/jbc.m117.801811] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/16/2017] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial cytochrome oxidase (COX) catalyzes the last step in the respiratory pathway. In the yeast Saccharomyces cerevisiae, this inner membrane complex is composed of 11 protein subunits. Expression of COX is assisted by some two dozen ancillary proteins that intercede at different stages of the assembly pathway. One such protein, Cox16p, encoded by COX16, was shown to be essential for the activity and assembly of COX. The function of Cox16p, however, has not been determined. We present evidence that Cox16p is present in Cox1p assembly intermediates and in COX. This is based on the finding that Cox16p, tagged with a dual polyhistidine and protein C tag, co-immunopurified with Cox1p assembly intermediates. The pulldown assays also indicated the presence of Cox16p in mature COX and in supercomplexes consisting of COX and the bc1 complex. From the Western signal strengths, Cox16p appears to be substoichiometric with Cox1p and Cox4p, which could indicate that Cox16p is only present in a fraction of COX. In conclusion, our results indicate that Cox16p is a constituent of several Cox1p assembly intermediates and of COX.
Collapse
Affiliation(s)
- Chen-Hsien Su
- From the Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Alexander Tzagoloff
- From the Department of Biological Sciences, Columbia University, New York, New York 10027
| |
Collapse
|
19
|
Singhal RK, Kruse C, Heidler J, Strecker V, Zwicker K, Düsterwald L, Westermann B, Herrmann JM, Wittig I, Rapaport D. Coi1 is a novel assembly factor of the yeast complex III-complex IV supercomplex. Mol Biol Cell 2017; 28:mbc.E17-02-0093. [PMID: 28794267 PMCID: PMC5620370 DOI: 10.1091/mbc.e17-02-0093] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 01/30/2023] Open
Abstract
The yeast bc1 complex (complex III) and cytochrome oxidase (complex IV) are mosaics of core subunits encoded by the mitochondrial genome and additional nuclear-encoded proteins imported from the cytosol. Both complexes build in the mitochondrial inner membrane various supramolecular assemblies. The formation of the individual complexes and their supercomplexes depends on the activity of dedicated assembly factors. We identified a so far uncharacterized mitochondrial protein (open reading frame YDR381C-A) as an important assembly factor for complex III, complex IV, and their supercomplexes. Therefore, we named this protein Cox interacting (Coi) 1. Deletion of COI1 results in decreased respiratory growth, reduced membrane potential, and hampered respiration, as well as slow fermentative growth at low temperature. In addition, coi1Δ cells harbour reduced steady-state levels of subunits of complexes III and IV as well as of the assembled complexes and supercomplexes. Interaction of Coi1 with respiratory chain subunits seems transient, as it appears to be a stoichiometric subunit neither of complex III nor of complex IV. Collectively, this work identifies a novel protein that plays a role in the assembly of the mitochondrial respiratory chain.
Collapse
Affiliation(s)
- Ravi K Singhal
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| | - Christine Kruse
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| | - Juliana Heidler
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
| | - Valentina Strecker
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
| | - Klaus Zwicker
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Lea Düsterwald
- Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | | - Ilka Wittig
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
- Cluster of Excellence "Macromolecular Complexes", Goethe University, Frankfurt am Main, Germany
- German Center of Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt, Germany
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| |
Collapse
|
20
|
García-Villegas R, Camacho-Villasana Y, Shingú-Vázquez MÁ, Cabrera-Orefice A, Uribe-Carvajal S, Fox TD, Pérez-Martínez X. The Cox1 C-terminal domain is a central regulator of cytochrome c oxidase biogenesis in yeast mitochondria. J Biol Chem 2017; 292:10912-10925. [PMID: 28490636 DOI: 10.1074/jbc.m116.773077] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/09/2017] [Indexed: 12/21/2022] Open
Abstract
Cytochrome c oxidase (CcO) is the last electron acceptor in the respiratory chain. The CcO core is formed by mitochondrial DNA-encoded Cox1, Cox2, and Cox3 subunits. Cox1 synthesis is highly regulated; for example, if CcO assembly is blocked, Cox1 synthesis decreases. Mss51 activates translation of COX1 mRNA and interacts with Cox1 protein in high-molecular-weight complexes (COA complexes) to form the Cox1 intermediary assembly module. Thus, Mss51 coordinates both Cox1 synthesis and assembly. We previously reported that the last 15 residues of the Cox1 C terminus regulate Cox1 synthesis by modulating an interaction of Mss51 with Cox14, another component of the COA complexes. Here, using site-directed mutagenesis of the mitochondrial COX1 gene from Saccharomyces cerevisiae, we demonstrate that mutations P521A/P522A and V524E disrupt the regulatory role of the Cox1 C terminus. These mutations, as well as C terminus deletion (Cox1ΔC15), reduced binding of Mss51 and Cox14 to COA complexes. Mss51 was enriched in a translationally active form that maintains full Cox1 synthesis even if CcO assembly is blocked in these mutants. Moreover, Cox1ΔC15, but not Cox1-P521A/P522A and Cox1-V524E, promoted formation of aberrant supercomplexes in CcO assembly mutants lacking Cox2 or Cox4 subunits. The aberrant supercomplex formation depended on the presence of cytochrome b and Cox3, supporting the idea that supercomplex assembly factors associate with Cox3 and demonstrating that supercomplexes can be formed even if CcO is inactive and not fully assembled. Our results indicate that the Cox1 C-terminal end is a key regulator of CcO biogenesis and that it is important for supercomplex formation/stability.
Collapse
Affiliation(s)
- Rodolfo García-Villegas
- From the Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Yolanda Camacho-Villasana
- From the Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Miguel Ángel Shingú-Vázquez
- the Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Alfredo Cabrera-Orefice
- the Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands, and
| | - Salvador Uribe-Carvajal
- From the Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Thomas D Fox
- the Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
| | - Xochitl Pérez-Martínez
- From the Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico,
| |
Collapse
|
21
|
Römpler K, Müller T, Juris L, Wissel M, Vukotic M, Hofmann K, Deckers M. Overlapping Role of Respiratory Supercomplex Factor Rcf2 and Its N-terminal Homolog Rcf3 in Saccharomyces cerevisiae. J Biol Chem 2016; 291:23769-23778. [PMID: 27662906 DOI: 10.1074/jbc.m116.734665] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial electron transport chain consists of individual protein complexes arranged into large macromolecular structures, termed respiratory chain supercomplexes or respirasomes. In the yeast Saccharomyces cerevisiae, respiratory chain supercomplexes form by association of the bc1 complex with the cytochrome c oxidase. Formation and maintenance of these assemblies are promoted by specific respiratory supercomplex factors, the Rcf proteins. For these proteins a regulatory function in bridging the electron transfer within supercomplexes has been proposed. Here we report on the maturation of Rcf2 into an N- and C-terminal peptide. We show that the previously uncharacterized Rcf3 (YBR255c-A) is a homolog of the N-terminal Rcf2 peptide, whereas Rcf1 is homologous to the C-terminal portion. Both Rcf3 and the C-terminal fragment of Rcf2 associate with monomeric cytochrome c oxidase and respiratory chain supercomplexes. A lack of Rcf2 and Rcf3 increases oxygen flux through the respiratory chain by up-regulation of the cytochrome c oxidase activity. A double gene deletion of RCF2 and RCF3 affects cellular survival under non-fermentable growth conditions, suggesting an overlapping role for both proteins in the regulation of the OXPHOS activity. Furthermore, our data suggest an association of all three Rcf proteins with the bc1 complex in the absence of a functional cytochrome c oxidase and identify a supercomplex independent interaction network of the Rcf proteins.
Collapse
Affiliation(s)
- Katharina Römpler
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Tobias Müller
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Lisa Juris
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Mirjam Wissel
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Milena Vukotic
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Kay Hofmann
- the Institute for Genetics, University of Cologne, D-50674 Cologne, Germany
| | - Markus Deckers
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| |
Collapse
|