1
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Zarges C, Riemer J. Oxidative protein folding in the intermembrane space of human mitochondria. FEBS Open Bio 2024. [PMID: 38867508 DOI: 10.1002/2211-5463.13839] [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: 04/02/2024] [Revised: 05/03/2024] [Accepted: 05/23/2024] [Indexed: 06/14/2024] Open
Abstract
The mitochondrial intermembrane space hosts a machinery for oxidative protein folding, the mitochondrial disulfide relay. This machinery imports a large number of soluble proteins into the compartment, where they are retained through oxidative folding. Additionally, the disulfide relay enhances the stability of many proteins by forming disulfide bonds. In this review, we describe the mitochondrial disulfide relay in human cells, its components, and their coordinated collaboration in mechanistic detail. We also discuss the human pathologies associated with defects in this machinery and its protein substrates, providing a comprehensive overview of its biological importance and implications for health.
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Affiliation(s)
| | - Jan Riemer
- Institute for Biochemistry, University of Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Germany
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2
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Huang L, Zhang L, Zhang Z, Tan F, Ma Y, Zeng X, Cao D, Deng L, Liu Q, Sun H, Shen B, Liao X. Loss of nephric augmenter of liver regeneration facilitates acute kidney injury via ACSL4-mediated ferroptosis. J Cell Mol Med 2024; 28:e18076. [PMID: 38088220 PMCID: PMC10844764 DOI: 10.1111/jcmm.18076] [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: 06/27/2023] [Revised: 11/01/2023] [Accepted: 11/25/2023] [Indexed: 02/08/2024] Open
Abstract
Ferroptosis, characterized by lipid accumulation in intracellular compartments, is related to acute kidney injury (AKI), but the mechanism remains obscure. In our previous study, the protective effect of augmenter of liver regeneration (ALR) on AKI was not fully clarified. In this study, we established an AKI mouse model by knocking out proximal tubule-specific ALR and an AKI cell model by inducing hypoxia, as well as enrolled AKI patients, to investigate the effects of ALR on ferroptosis and the progression of AKI. We found that ALR knockout aggravated ferroptosis and increased ROS accumulation and mitochondrial damage, whereas ALR overexpression attenuated ferroptosis through clearance of ROS and maintenance of mitochondrial morphology. Mechanistically, we demonstrated that ALR could directly bind to long-chain-fatty-acid-CoA ligase 4 (ACSL4) and further inhibit the expression of ACSL4 by interacting with certain regions. By resolution liquid chromatography coupled with triple quadruple mass spectrometry, we found that ALR could reduce the contents of polyunsaturated fatty acids, especially arachidonic acid. In addition, we showed that ALR binds to ACSL4 and attenuates oxylipin accumulation, exerting a protective effect against ferroptosis in AKI. Therefore, targeting renal ALR can attenuate ferroptosis and can offer a promising strategy for the treatment of AKI.
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Affiliation(s)
- Lili Huang
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Ling Zhang
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Zheng Zhang
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
- Department of Cell Biology and GeneticsChongqing Medical UniversityChongqingChina
| | - Fangyan Tan
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Yixin Ma
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Xujia Zeng
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Dan Cao
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Lili Deng
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
| | - Qi Liu
- Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral HepatitisThe Second Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Hang Sun
- Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral HepatitisThe Second Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Bingbing Shen
- Department of NephrologyChongqing University Central Hospital, Chongqing Emergency Medical CenterChongqingChina
| | - Xiaohui Liao
- Department of NephrologyThe Second Affiliated Hospital, Chongqing Medical UniversityChongqingChina
- Kuanren Laboratory of Translational Lipidology, Centre for Lipid ResearchThe Second Affiliated Hospital of Chongqing Medical UniversityChongqingChina
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3
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Muzzioli R, Gallo A. The Interaction and Effect of a Small MitoBlock Library as Inhibitor of ALR Protein-Protein Interaction Pathway. Int J Mol Sci 2024; 25:1174. [PMID: 38256258 PMCID: PMC10816046 DOI: 10.3390/ijms25021174] [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: 12/13/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
MIA40 and ALR of the MIA pathway mediate the import of protein precursors that form disulfides into the mitochondrial intermembrane space. This import pathway is suggested to be a linear pathway in which MIA40 first binds to the precursor via a disulfide linkage and oxidizes it. Subsequently, ALR re-oxidizes MIA40 and then ALR transfers electrons to terminal electron acceptors. However, the precise mechanism by which ALR and MIA40 coordinate translocation is unknown. With a collection of small molecule modulators (MB-5 to MB-9 and MB-13) that inhibit ALR activity, we characterized the import mechanism in mitochondria. NMR studies show that most of the compounds bind to a similar region in ALR. Mechanistic studies with small molecules demonstrate that treatment with compound MB-6 locks the precursor in a state bound to MIA40, blocking re-oxidation of MIA40 by ALR. Thus, small molecules that target a similar region in ALR alter the dynamics of the MIA import pathway differently, resulting in a set of probes that are useful for studying the catalysis of the redox-regulated import pathway in model systems.
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4
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Peker E, Weiss K, Song J, Zarges C, Gerlich S, Boehm V, Trifunovic A, Langer T, Gehring NH, Becker T, Riemer J. A two-step mitochondrial import pathway couples the disulfide relay with matrix complex I biogenesis. J Cell Biol 2023; 222:e202210019. [PMID: 37159021 PMCID: PMC10174193 DOI: 10.1083/jcb.202210019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 03/03/2023] [Accepted: 04/06/2023] [Indexed: 05/10/2023] Open
Abstract
Mitochondria critically rely on protein import and its tight regulation. Here, we found that the complex I assembly factor NDUFAF8 follows a two-step import pathway linking IMS and matrix import systems. A weak targeting sequence drives TIM23-dependent NDUFAF8 matrix import, and en route, allows exposure to the IMS disulfide relay, which oxidizes NDUFAF8. Import is closely surveyed by proteases: YME1L prevents accumulation of excess NDUFAF8 in the IMS, while CLPP degrades reduced NDUFAF8 in the matrix. Therefore, NDUFAF8 can only fulfil its function in complex I biogenesis if both oxidation in the IMS and subsequent matrix import work efficiently. We propose that the two-step import pathway for NDUFAF8 allows integration of the activity of matrix complex I biogenesis pathways with the activity of the mitochondrial disulfide relay system in the IMS. Such coordination might not be limited to NDUFAF8 as we identified further proteins that can follow such a two-step import pathway.
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Affiliation(s)
- Esra Peker
- Institute for Biochemistry, University of Cologne, Cologne, Germany
| | - Konstantin Weiss
- Institute for Biochemistry, University of Cologne, Cologne, Germany
| | - Jiyao Song
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christine Zarges
- Institute for Biochemistry, University of Cologne, Cologne, Germany
| | - Sarah Gerlich
- Institute for Biochemistry, University of Cologne, Cologne, Germany
| | - Volker Boehm
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Aleksandra Trifunovic
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - Thomas Langer
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Mitochondrial Proteostasis, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Niels H. Gehring
- Institute for Genetics, University of Cologne, Cologne, Germany
- Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Jan Riemer
- Institute for Biochemistry, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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5
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Jacobs LJHC, Riemer J. Maintenance of small molecule redox homeostasis in mitochondria. FEBS Lett 2023; 597:205-223. [PMID: 36030088 DOI: 10.1002/1873-3468.14485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/18/2022] [Accepted: 08/21/2022] [Indexed: 01/26/2023]
Abstract
Compartmentalisation of eukaryotic cells enables fundamental otherwise often incompatible cellular processes. Establishment and maintenance of distinct compartments in the cell relies not only on proteins, lipids and metabolites but also on small redox molecules. In particular, small redox molecules such as glutathione, NAD(P)H and hydrogen peroxide (H2 O2 ) cooperate with protein partners in dedicated machineries to establish specific subcellular redox compartments with conditions that enable oxidative protein folding and redox signalling. Dysregulated redox homeostasis has been directly linked with a number of diseases including cancer, neurological disorders, cardiovascular diseases, obesity, metabolic diseases and ageing. In this review, we will summarise mechanisms regulating establishment and maintenance of redox homeostasis in the mitochondrial subcompartments of mammalian cells.
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Affiliation(s)
- Lianne J H C Jacobs
- Institute for Biochemistry and Center of Excellence for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Germany
| | - Jan Riemer
- Institute for Biochemistry and Center of Excellence for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Germany
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Dong Y, Zhang Y, Feng Y, An W. The protective roles of augmenter of liver regeneration in hepatocytes in the non-alcoholic fatty liver disease. Front Pharmacol 2022; 13:928606. [PMID: 36304168 PMCID: PMC9592723 DOI: 10.3389/fphar.2022.928606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/20/2022] [Indexed: 11/23/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) occurs in 25% of the global population and manifests as lipid deposition, hepatocyte injury, activation of Kupffer and stellate cells, and steatohepatitis. Predominantly expressed in hepatocytes, the augmenter of liver regeneration (ALR) is a key factor in liver regulation that can alleviate fatty liver disease and protect the liver from abnormal liver lipid metabolism. ALR has three isoforms (15-, 21-, and 23-kDa), amongst which 23-kDa ALR is the most extensively studied. The 23-kDa ALR isoform is a sulfhydryl oxidase that resides primarily in the mitochondrial intermembrane space (IMS), whereby it protects the liver against various types of injury. In this review, we describe the role of ALR in regulating hepatocytes in the context of NAFLD. We also discuss questions about ALR that remain to be explored in the future. In conclusion, ALR appears to be a promising therapeutic target for treating NAFLD.
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Affiliation(s)
- Yuan Dong
- Department of Science and Technology, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Yuejie Zhang
- Department of Science and Technology, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Yingmei Feng
- Department of Science and Technology, Beijing Youan Hospital, Capital Medical University, Beijing, China
- *Correspondence: Yingmei Feng, ; Wei An,
| | - Wei An
- Department of Cell Biology, Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration, Beijing, China
- *Correspondence: Yingmei Feng, ; Wei An,
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Dimogkioka AR, Lees J, Lacko E, Tokatlidis K. Protein import in mitochondria biogenesis: guided by targeting signals and sustained by dedicated chaperones. RSC Adv 2021; 11:32476-32493. [PMID: 35495482 PMCID: PMC9041937 DOI: 10.1039/d1ra04497d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/25/2021] [Indexed: 12/31/2022] Open
Abstract
Mitochondria have a central role in cellular metabolism; they are responsible for the biosynthesis of amino acids, lipids, iron-sulphur clusters and regulate apoptosis. About 99% of mitochondrial proteins are encoded by nuclear genes, so the biogenesis of mitochondria heavily depends on protein import pathways into the organelle. An intricate system of well-studied import machinery facilitates the import of mitochondrial proteins. In addition, folding of the newly synthesized proteins takes place in a busy environment. A system of folding helper proteins, molecular chaperones and co-chaperones, are present to maintain proper conformation and thus avoid protein aggregation and premature damage. The components of the import machinery are well characterised, but the targeting signals and how they are recognised and decoded remains in some cases unclear. Here we provide some detail on the types of targeting signals involved in the protein import process. Furthermore, we discuss the very elaborate chaperone systems of the intermembrane space that are needed to overcome the particular challenges for the folding process in this compartment. The mechanisms that sustain productive folding in the face of aggregation and damage in mitochondria are critical components of the stress response and play an important role in cell homeostasis.
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Affiliation(s)
- Anna-Roza Dimogkioka
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
| | - Jamie Lees
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
| | - Erik Lacko
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
| | - Kostas Tokatlidis
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
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8
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Geldon S, Fernández-Vizarra E, Tokatlidis K. Redox-Mediated Regulation of Mitochondrial Biogenesis, Dynamics, and Respiratory Chain Assembly in Yeast and Human Cells. Front Cell Dev Biol 2021; 9:720656. [PMID: 34557489 PMCID: PMC8452992 DOI: 10.3389/fcell.2021.720656] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/04/2021] [Indexed: 12/24/2022] Open
Abstract
Mitochondria are double-membrane organelles that contain their own genome, the mitochondrial DNA (mtDNA), and reminiscent of its endosymbiotic origin. Mitochondria are responsible for cellular respiration via the function of the electron oxidative phosphorylation system (OXPHOS), located in the mitochondrial inner membrane and composed of the four electron transport chain (ETC) enzymes (complexes I-IV), and the ATP synthase (complex V). Even though the mtDNA encodes essential OXPHOS components, the large majority of the structural subunits and additional biogenetical factors (more than seventy proteins) are encoded in the nucleus and translated in the cytoplasm. To incorporate these proteins and the rest of the mitochondrial proteome, mitochondria have evolved varied, and sophisticated import machineries that specifically target proteins to the different compartments defined by the two membranes. The intermembrane space (IMS) contains a high number of cysteine-rich proteins, which are mostly imported via the MIA40 oxidative folding system, dependent on the reduction, and oxidation of key Cys residues. Several of these proteins are structural components or assembly factors necessary for the correct maturation and function of the ETC complexes. Interestingly, many of these proteins are involved in the metalation of the active redox centers of complex IV, the terminal oxidase of the mitochondrial ETC. Due to their function in oxygen reduction, mitochondria are the main generators of reactive oxygen species (ROS), on both sides of the inner membrane, i.e., in the matrix and the IMS. ROS generation is important due to their role as signaling molecules, but an excessive production is detrimental due to unwanted oxidation reactions that impact on the function of different types of biomolecules contained in mitochondria. Therefore, the maintenance of the redox balance in the IMS is essential for mitochondrial function. In this review, we will discuss the role that redox regulation plays in the maintenance of IMS homeostasis as well as how mitochondrial ROS generation may be a key regulatory factor for ETC biogenesis, especially for complex IV.
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Affiliation(s)
| | - Erika Fernández-Vizarra
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kostas Tokatlidis
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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9
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Finger Y, Riemer J. Protein import by the mitochondrial disulfide relay in higher eukaryotes. Biol Chem 2021; 401:749-763. [PMID: 32142475 DOI: 10.1515/hsz-2020-0108] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/24/2020] [Indexed: 12/19/2022]
Abstract
The proteome of the mitochondrial intermembrane space (IMS) contains more than 100 proteins, all of which are synthesized on cytosolic ribosomes and consequently need to be imported by dedicated machineries. The mitochondrial disulfide relay is the major import machinery for soluble proteins in the IMS. Its major component, the oxidoreductase MIA40, interacts with incoming substrates, retains them in the IMS, and oxidatively folds them. After this reaction, MIA40 is reoxidized by the sulfhydryl oxidase augmenter of liver regeneration, which couples disulfide formation by this machinery to the activity of the respiratory chain. In this review, we will discuss the import of IMS proteins with a focus on recent findings showing the diversity of disulfide relay substrates, describing the cytosolic control of this import system and highlighting the physiological relevance of the disulfide relay machinery in higher eukaryotes.
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Affiliation(s)
- Yannik Finger
- Institute for Biochemistry, Redox Biochemistry, University of Cologne, Zülpicher Str. 47a/R. 3.49, D-50674 Cologne, Germany
| | - Jan Riemer
- Department of Chemistry, Institute for Biochemistry, Redox Biochemistry, University of Cologne, and Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases, Zülpicher Str. 47a/R. 3.49, D-50674 Cologne, Germany
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10
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Edwards R, Gerlich S, Tokatlidis K. The biogenesis of mitochondrial intermembrane space proteins. Biol Chem 2021; 401:737-747. [PMID: 32061164 DOI: 10.1515/hsz-2020-0114] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 02/13/2020] [Indexed: 01/09/2023]
Abstract
The mitochondrial intermembrane space (IMS) houses a large spectrum of proteins with distinct and critical functions. Protein import into this mitochondrial sub-compartment is underpinned by an intriguing variety of pathways, many of which are still poorly understood. The constricted volume of the IMS and the topological segregation by the inner membrane cristae into a bulk area surrounded by the boundary inner membrane and the lumen within the cristae is an important factor that adds to the complexity of the protein import, folding and assembly processes. We discuss the main import pathways into the IMS, but also how IMS proteins are degraded or even retro-translocated to the cytosol in an integrated network of interactions that is necessary to maintain a healthy balance of IMS proteins under physiological and cellular stress conditions. We conclude this review by highlighting new and exciting perspectives in this area with a view to develop a better understanding of yet unknown, likely unconventional import pathways, how presequence-less proteins can be targeted and the basis for dual localisation in the IMS and the cytosol. Such knowledge is critical to understanding the dynamic changes of the IMS proteome in response to stress, and particularly important for maintaining optimal mitochondrial fitness.
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Affiliation(s)
- Ruairidh Edwards
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow, G12 8QQ Scotland, UK
| | - Sarah Gerlich
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow, G12 8QQ Scotland, UK.,Department for Chemistry, Institute for Biochemistry, University of Cologne, 50674 Cologne, Germany
| | - Kostas Tokatlidis
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow, G12 8QQ Scotland, UK
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11
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Erv1 and Cytochrome c Mediate Rapid Electron Transfer via A Collision-Type Interaction. J Mol Biol 2021; 433:167045. [PMID: 33971209 DOI: 10.1016/j.jmb.2021.167045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/01/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022]
Abstract
Being essential for oxidative protein folding in the mitochondrial intermembrane space, the mitochondrial disulfide relay relies on the electron transfer (ET) from the sulfhydryl oxidase Erv1 to cytochrome c (Cc). Using solution NMR spectroscopy, we demonstrate that while the yeast Cc-Erv1 system is functionally active, no observable binding of the protein partners takes place. The transient interaction between Erv1 and Cc can be rationalized by molecular modeling, suggesting that a large surface area of Erv1 can sustain a fast ET to Cc via a collision-type mechanism, without the need for a canonical protein complex formation. We suggest that, by preventing the direct ET to molecular oxygen (O2), the collision-type Cc-Erv1 interaction plays a role in protecting the organism against reactive oxygen species.
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12
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The Mia40/CHCHD4 Oxidative Folding System: Redox Regulation and Signaling in the Mitochondrial Intermembrane Space. Antioxidants (Basel) 2021; 10:antiox10040592. [PMID: 33921425 PMCID: PMC8069373 DOI: 10.3390/antiox10040592] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/20/2022] Open
Abstract
Mitochondria are critical for several cellular functions as they control metabolism, cell physiology, and cell death. The mitochondrial proteome consists of around 1500 proteins, the vast majority of which (about 99% of them) are encoded by nuclear genes, with only 13 polypeptides in human cells encoded by mitochondrial DNA. Therefore, it is critical for all the mitochondrial proteins that are nuclear-encoded to be targeted precisely and sorted specifically to their site of action inside mitochondria. These processes of targeting and sorting are catalysed by protein translocases that operate in each one of the mitochondrial sub-compartments. The main protein import pathway for the intermembrane space (IMS) recognises proteins that are cysteine-rich, and it is the only import pathway that chemically modifies the imported precursors by introducing disulphide bonds to them. In this manner, the precursors are trapped in the IMS in a folded state. The key component of this pathway is Mia40 (called CHCHD4 in human cells), which itself contains cysteine motifs and is subject to redox regulation. In this review, we detail the basic components of the MIA pathway and the disulphide relay mechanism that underpins the electron transfer reaction along the oxidative folding mechanism. Then, we discuss the key protein modulators of this pathway and how they are interlinked to the small redox-active molecules that critically affect the redox state in the IMS. We present also evidence that the mitochondrial redox processes that are linked to iron–sulfur clusters biogenesis and calcium homeostasis coalesce in the IMS at the MIA machinery. The fact that the MIA machinery and several of its interactors and substrates are linked to a variety of common human diseases connected to mitochondrial dysfunction highlight the potential of redox processes in the IMS as a promising new target for developing new treatments for some of the most complex and devastating human diseases.
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13
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Chang HC, Shapiro JS, Jiang X, Senyei G, Sato T, Geier J, Sawicki KT, Ardehali H. Augmenter of liver regeneration regulates cellular iron homeostasis by modulating mitochondrial transport of ATP-binding cassette B8. eLife 2021; 10:e65158. [PMID: 33835027 PMCID: PMC8055271 DOI: 10.7554/elife.65158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/06/2021] [Indexed: 12/15/2022] Open
Abstract
Chronic loss of Augmenter of Liver Regeneration (ALR) results in mitochondrial myopathy with cataracts; however, the mechanism for this disorder remains unclear. Here, we demonstrate that loss of ALR, a principal component of the MIA40/ALR protein import pathway, results in impaired cytosolic Fe/S cluster biogenesis in mammalian cells. Mechanistically, MIA40/ALR facilitates the mitochondrial import of ATP-binding cassette (ABC)-B8, an inner mitochondrial membrane protein required for cytoplasmic Fe/S cluster maturation, through physical interaction with ABCB8. Downregulation of ALR impairs mitochondrial ABCB8 import, reduces cytoplasmic Fe/S cluster maturation, and increases cellular iron through the iron regulatory protein-iron response element system. Our finding thus provides a mechanistic link between MIA40/ALR import machinery and cytosolic Fe/S cluster maturation through the mitochondrial import of ABCB8, and offers a potential explanation for the pathology seen in patients with ALR mutations.
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Affiliation(s)
- Hsiang-Chun Chang
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Jason Solomon Shapiro
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Xinghang Jiang
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Grant Senyei
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Teruki Sato
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Justin Geier
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Konrad T Sawicki
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
| | - Hossein Ardehali
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University School of MedicineChicagoUnited States
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14
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Huang J, Xie P, Dong Y, An W. Inhibition of Drp1 SUMOylation by ALR protects the liver from ischemia-reperfusion injury. Cell Death Differ 2021; 28:1174-1192. [PMID: 33110216 PMCID: PMC8027887 DOI: 10.1038/s41418-020-00641-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 01/30/2023] Open
Abstract
Hepatic ischemic reperfusion injury (IRI) is a common complication of liver surgery. Although an imbalance between mitochondrial fission and fusion has been identified as the cause of IRI, the detailed mechanism remains unclear. Augmenter of liver regeneration (ALR) was reported to prevent mitochondrial fission by inhibiting dynamin-related protein 1 (Drp1) phosphorylation, contributing partially to its liver protection. Apart from phosphorylation, Drp1 activity is also regulated by small ubiquitin-like modification (SUMOylation), which accelerates mitochondrial fission. This study aimed to investigate whether ALR-mediated protection from hepatic IRI might be associated with an effect on Drp1 SUMOylation. Liver tissues were harvested from both humans and from heterozygous ALR knockout mice, which underwent IRI. The SUMOylation and phosphorylation of Drp1 and their modulation by ALR were investigated. Hepatic Drp1 SUMOylation was significantly increased in human transplanted livers and IRI-livers of mice. ALR-transfection significantly decreased Drp1 SUMOylation, attenuated the IRI-induced mitochondrial fission and preserved mitochondrial stability and function. This study showed that the binding of transcription factor Yin Yang-1 (YY1) to its downstream target gene UBA2, a subunit of SUMO-E1 enzyme heterodimer, was critical to control Drp1 SUMOylation. By interacting with YY1, ALR inhibits its nuclear import and dramatically decreases the transcriptional level of UBA2. Consequently, mitochondrial fission was significantly reduced, and mitochondrial function was maintained. This study showed that the regulation of Drp1 SUMOylation by ALR protects mitochondria from fission, rescuing hepatocytes from IRI-induced apoptosis. These new findings provide a potential target for clinical intervention to reduce the effects of IRI during hepatic surgery.
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Affiliation(s)
- Jing Huang
- grid.24696.3f0000 0004 0369 153XDepartment of Cell Biology, Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration, Beijing, China
| | - Ping Xie
- grid.24696.3f0000 0004 0369 153XDepartment of Cell Biology, Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration, Beijing, China
| | - Yuan Dong
- grid.24696.3f0000 0004 0369 153XDepartment of Cell Biology, Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration, Beijing, China
| | - Wei An
- grid.24696.3f0000 0004 0369 153XDepartment of Cell Biology, Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration, Beijing, China
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15
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CHCHD4 (MIA40) and the mitochondrial disulfide relay system. Biochem Soc Trans 2021; 49:17-27. [PMID: 33599699 PMCID: PMC7925007 DOI: 10.1042/bst20190232] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/19/2020] [Accepted: 01/06/2021] [Indexed: 12/13/2022]
Abstract
Mitochondria are pivotal for normal cellular physiology, as they perform a crucial role in diverse cellular functions and processes, including respiration and the regulation of bioenergetic and biosynthetic pathways, as well as regulating cellular signalling and transcriptional networks. In this way, mitochondria are central to the cell's homeostatic machinery, and as such mitochondrial dysfunction underlies the pathology of a diverse range of diseases including mitochondrial disease and cancer. Mitochondrial import pathways and targeting mechanisms provide the means to transport into mitochondria the hundreds of nuclear-encoded mitochondrial proteins that are critical for the organelle's many functions. One such import pathway is the highly evolutionarily conserved disulfide relay system (DRS) within the mitochondrial intermembrane space (IMS), whereby proteins undergo a form of oxidation-dependent protein import. A central component of the DRS is the oxidoreductase coiled-coil-helix-coiled-coil-helix (CHCH) domain-containing protein 4 (CHCHD4, also known as MIA40), the human homologue of yeast Mia40. Here, we summarise the recent advances made to our understanding of the role of CHCHD4 and the DRS in physiology and disease, with a specific focus on the emerging importance of CHCHD4 in regulating the cellular response to low oxygen (hypoxia) and metabolism in cancer.
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16
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Wang X, Dong LY, Gai QJ, Ai WL, Wu Y, Xiao WC, Zhang J, An W. Lack of Augmenter of Liver Regeneration Disrupts Cholesterol Homeostasis of Liver in Mice by Inhibiting the AMPK Pathway. Hepatol Commun 2020; 4:1149-1167. [PMID: 32766475 PMCID: PMC7395071 DOI: 10.1002/hep4.1532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 01/18/2023] Open
Abstract
It is well known that excessive cholesterol accumulation within hepatocytes deteriorates nonalcoholic fatty liver disease (NAFLD). Augmenter of liver regeneration (ALR) has been reported to alleviate NAFLD through anti-apoptosis; however, whether ALR could protect liver from cholesterol-induced NAFLD remains unclear. Mice with heterozygous deletion of Gfer (the gene for ALR, Gfer +/-) were generated, and liver steatosis was induced by either choline-deficient ethionine-supplemented, methionine choline-deficient diet for 4 weeks, or high-fat diet for 16 weeks. The results showed that Gfer +/- mice developed a more severe fatty liver phenotype than Gfer +/+ mice. The livers of Gfer +/- mice exhibited a higher concentration of cholesterol and low-density lipoprotein compared with the normal mice. Transcriptome-based analysis predicts low-density lipoprotein receptor (LDLR) primarily involved in the metabolic pathway. The experiments further indicate that cholesterol accumulation within hepatocytes is closely associated with enhancing the expression of LDLR and activation of sterol regulatory element binding protein 2 (SREBP2). Because adenosine monophosphate-activated protein kinase (AMPK) is a critical regulator of SREBP2 activation, we measured whether the activity of AMPK was regulated by ALR. We found that knockdown of ALR expression inhibited the phosphorylation of LKB1, an upstream activator of AMPK, followed by AMPK inactivation and SREBP2 maturation/nuclear translocation, leading to extensive cholesterol accumulation. Meanwhile, cellular oxidative stress increased as a result of ALR knockdown, indicating that ALR might also have a role in suppressing reactive oxygen species production. Conclusion: Our results confirm that ALR regulates cholesterol metabolism and alleviates hepatic steatosis probably through the LKB1-AMPK-SREBP2-LDLR pathway in vivo and in vitro, providing a putative mechanism for combating fatty liver disease.
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Affiliation(s)
- Xin Wang
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Ling-Yue Dong
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Qu-Jing Gai
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Wei-Lun Ai
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Yuan Wu
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Wei-Chun Xiao
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Jing Zhang
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
| | - Wei An
- Department of Cell Biology Capital Medical University and the Municipal Key Laboratory for Liver Protection and Regulation of Regeneration Beijing China
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17
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Habich M, Salscheider SL, Murschall LM, Hoehne MN, Fischer M, Schorn F, Petrungaro C, Ali M, Erdogan AJ, Abou-Eid S, Kashkar H, Dengjel J, Riemer J. Vectorial Import via a Metastable Disulfide-Linked Complex Allows for a Quality Control Step and Import by the Mitochondrial Disulfide Relay. Cell Rep 2020; 26:759-774.e5. [PMID: 30650365 DOI: 10.1016/j.celrep.2018.12.092] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/15/2018] [Accepted: 12/20/2018] [Indexed: 01/31/2023] Open
Abstract
Disulfide formation in the mitochondrial intermembrane space (IMS) is an essential process. It is catalyzed by the disulfide relay machinery, which couples substrate import and oxidation. The machinery relies on the oxidoreductase and chaperone CHCHD4-Mia40. Here, we report on the driving force for IMS import and on a redox quality control mechanism. We demonstrate that unfolded reduced proteins, upon translocation into the IMS, initiate formation of a metastable disulfide-linked complex with CHCHD4. If this interaction does not result in productive oxidation, then substrates are released to the cytosol and degraded by the proteasome. Based on these data, we propose a redox quality control step at the level of the disulfide-linked intermediate that relies on the vectorial nature of IMS import. Our findings also provide the mechanistic framework to explain failures in import of numerous human disease mutants in CHCHD4 substrates.
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Affiliation(s)
- Markus Habich
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Silja Lucia Salscheider
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Lena Maria Murschall
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Michaela Nicole Hoehne
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Manuel Fischer
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Fabian Schorn
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC) and Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, CECAD Research Center, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Carmelina Petrungaro
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Muna Ali
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Alican J Erdogan
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany
| | - Shadi Abou-Eid
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Hamid Kashkar
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC) and Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, CECAD Research Center, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Joern Dengjel
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Jan Riemer
- Institute for Biochemistry, Department of Chemistry, University of Cologne, Zuelpicher Str. 47a/R. 3.49, 50674 Cologne, Germany.
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18
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AIF meets the CHCHD4/Mia40-dependent mitochondrial import pathway. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165746. [PMID: 32105825 DOI: 10.1016/j.bbadis.2020.165746] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 02/06/2023]
Abstract
In the mitochondria of healthy cells, Apoptosis-Inducing factor (AIF) is required for the optimal functioning of the respiratory chain machinery, mitochondrial integrity, cell survival, and proliferation. In all analysed species, it was revealed that the downregulation or depletion of AIF provokes mainly the post-transcriptional loss of respiratory chain Complex I protein subunits. Recent progress in the field has revealed that AIF fulfils its mitochondrial pro-survival function by interacting physically and functionally with CHCHD4, the evolutionarily-conserved human homolog of yeast Mia40. The redox-regulated CHCHD4/Mia40-dependent import machinery operates in the intermembrane space of the mitochondrion and controls the import of a set of nuclear-encoded cysteine-motif carrying protein substrates. In addition to their participation in the biogenesis of specific respiratory chain protein subunits, CHCHD4/Mia40 substrates are also implicated in the control of redox regulation, antioxidant response, translation, lipid homeostasis and mitochondrial ultrastructure and dynamics. Here, we discuss recent insights on the AIF/CHCHD4-dependent protein import pathway and review current data concerning the CHCHD4/Mia40 protein substrates in metazoan. Recent findings and the identification of disease-associated mutations in AIF or in specific CHCHD4/Mia40 substrates have highlighted these proteins as potential therapeutic targets in a variety of human disorders.
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19
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Ceh-Pavia E, Tang X, Liu Y, Heyes DJ, Zhao B, Xiao P, Lu H. Redox characterisation of Erv1, a key component for protein import and folding in yeast mitochondria. FEBS J 2019; 287:2281-2291. [PMID: 31713999 PMCID: PMC7318334 DOI: 10.1111/febs.15136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 10/08/2019] [Accepted: 11/10/2019] [Indexed: 11/29/2022]
Abstract
The mitochondrial import and assembly (MIA) pathway plays a vitally important role in import and oxidative folding of mitochondrial proteins. Erv1, a member of the FAD-dependent Erv1/ALR disulphide bond generating enzyme family, is a key player of the MIA pathway. Although considerable progress has been made, the molecular mechanism of electron transfer within Erv1 is still not fully understood. The reduction potentials of the three redox centres were previously determined to be -320 mV for the shuttle disulphide, -150 mV for the active-site disulphide and -215 mV for FAD cofactor. However, it is unknown why FAD of Erv1 has such a low potential compared with other sulfhydryl oxidases, and why the shuttle disulphide has a potential as low as many of the stable structural disulphides of the substrates of MIA pathway. In this study, the three reduction potentials of Erv1 were reassessed using the wild-type and inactive mutants of Erv1 under anaerobic conditions. Our results show that the standard potentials for the shuttle and active-site disulphides are approximately -250 mV and -215 ~ -260 mV, respectively, and the potential for FAD cofactor is -148 mV. Our results support a model that both disulphide bonds are redox-active, and electron flow in Erv1 is thermodynamically favourable. Furthermore, the redox behaviour of Erv1 was confirmed, for the first time using Mia40, the physiological electron donor of Erv1. Together with previous studies on proteins of MIA pathway, we conclude that electron flow in the MIA pathway is a thermodynamically favourable, smoothly downhill process for all steps. DATABASE: Erv1: EC 1.8.3.2.
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Affiliation(s)
- Efrain Ceh-Pavia
- Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, UK
| | - Xiaofan Tang
- Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, UK.,School of Materials, University of Manchester, UK
| | - Yawen Liu
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, China
| | - Derren J Heyes
- Manchester Institute of Biotechnology, University of Manchester, UK
| | - Bing Zhao
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, China
| | - Ping Xiao
- School of Materials, University of Manchester, UK
| | - Hui Lu
- Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, UK
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20
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Weiss TS, Lupke M, Dayoub R, Geissler EK, Schlitt HJ, Melter M, Eggenhofer E. Augmenter of Liver Regeneration Reduces Ischemia Reperfusion Injury by Less Chemokine Expression, Gr-1 Infiltration and Oxidative Stress. Cells 2019; 8:cells8111421. [PMID: 31718093 PMCID: PMC6912457 DOI: 10.3390/cells8111421] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 12/14/2022] Open
Abstract
Hepatic ischemia reperfusion injury (IRI) is a major complication in liver resection and transplantation. Here, we analyzed the impact of recombinant human augmenter of liver regeneration (rALR), an anti-oxidative and anti-apoptotic protein, on the deleterious process induced by ischemia reperfusion (IR). Application of rALR reduced tissue damage (necrosis), levels of lipid peroxidation (oxidative stress) and expression of anti-oxidative genes in a mouse IRI model. Damage associated molecule pattern (DAMP) and inflammatory cytokines such as HMGB1 and TNFα, were not affected by rALR. Furthermore, we evaluated infiltration of inflammatory cells into liver tissue after IRI and found no change in CD3 or γδTCR positive cells, or expression of IL17/IFNγ by γδTCR cells. The quantity of Gr-1 positive cells (neutrophils), and therefore, myeloperoxidase activity, was lower in rALR-treated mice. Moreover, we found under hypoxic conditions attenuated ROS levels after ALR treatment in RAW264.7 cells and in primary mouse hepatocytes. Application of rALR also led to reduced expression of chemo-attractants like CXCL1, CXCL2 and CCl2 in hepatocytes. In addition, ALR expression was increased in IR mouse livers after 3 h and in biopsies from human liver transplants with minimal signs of tissue damage. Therefore, ALR attenuates IRI through reduced neutrophil tissue infiltration mediated by lower expression of key hepatic chemokines and reduction of ROS generation.
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Affiliation(s)
- Thomas S. Weiss
- University Children Hospital (KUNO), University Hospital Regensburg, 93053 Regensburg, Germany; (M.L.); (R.D.); (M.M.)
- Center for Liver Cell Research, University Hospital Regensburg, 93053 Regensburg, Germany
- Correspondence: ; Tel.: +49-9419442195
| | - Madeleine Lupke
- University Children Hospital (KUNO), University Hospital Regensburg, 93053 Regensburg, Germany; (M.L.); (R.D.); (M.M.)
| | - Rania Dayoub
- University Children Hospital (KUNO), University Hospital Regensburg, 93053 Regensburg, Germany; (M.L.); (R.D.); (M.M.)
| | - Edward K. Geissler
- Department of Surgery, University Hospital Regensburg, 93053 Regensburg, Germany; (E.K.G.); (H.J.S.); (E.E.)
| | - Hans J. Schlitt
- Department of Surgery, University Hospital Regensburg, 93053 Regensburg, Germany; (E.K.G.); (H.J.S.); (E.E.)
| | - Michael Melter
- University Children Hospital (KUNO), University Hospital Regensburg, 93053 Regensburg, Germany; (M.L.); (R.D.); (M.M.)
| | - Elke Eggenhofer
- Department of Surgery, University Hospital Regensburg, 93053 Regensburg, Germany; (E.K.G.); (H.J.S.); (E.E.)
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21
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Tang X, Ang SK, Ceh-Pavia E, Heyes DJ, Lu H. Kinetic characterisation of Erv1, a key component for protein import and folding in yeast mitochondria. FEBS J 2019; 287:1220-1231. [PMID: 31569302 PMCID: PMC7155059 DOI: 10.1111/febs.15077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/22/2019] [Accepted: 09/29/2019] [Indexed: 12/04/2022]
Abstract
Yeast (Saccharomyces cerevisiae) essential for respiration and viability 1 (Erv1; EC number http://www.chem.qmul.ac.uk/iubmb/enzyme/1/8/3/2.html), a member of the flavin adenine dinucleotide‐dependent Erv1/ALR disulphide bond generating enzyme family, works together with Mia40 to catalyse protein import and oxidative folding in the mitochondrial intermembrane space. Erv1/ALR functions either as an oxidase or cytochrome c reductase by passing electrons from a thiol substrate to molecular oxygen (O2) or cytochrome c, respectively. However, the substrate specificity for oxygen and cytochrome c is not fully understood. In this study, the oxidase and cytochrome c reductase kinetics of yeast Erv1 were investigated in detail, under aerobic and anaerobic conditions, using stopped‐flow absorption spectroscopy and oxygen consumption analysis. Using DTT as an electron donor, our results show that cytochrome c is ~ 7‐ to 15‐fold more efficient than O2 as electron acceptors for yeast Erv1, and that O2 is a competitive inhibitor of Erv1 cytochrome c reductase activity. In addition, Mia40, the physiological thiol substrate of Erv1, was used as an electron donor for Erv1 in a detailed enzyme kinetic study. Different enzyme kinetic kcat and Km values were obtained with Mia40 compared to DTT, suggesting that Mia40 modulates Erv1 enzyme kinetics. Taken together, this study shows that Erv1 is a moderately active enzyme with the ability to use both O2 and cytochrome c as the electron acceptors, indicating that Erv1 contributes to mitochondrial hydrogen peroxide production. Our results also suggest that Mia40‐Erv1 system may involve in regulation of the redox state of glutathione in the mitochondrial intermembrane space. Erv1 EC number http://www.chem.qmul.ac.uk/iubmb/enzyme/1/8/3/2.html.
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Affiliation(s)
- Xiaofan Tang
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK.,School of Materials, University of Manchester, UK
| | - Swee Kim Ang
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Efrain Ceh-Pavia
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Derren J Heyes
- Manchester Institute of Biotechnology, University of Manchester, UK
| | - Hui Lu
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
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22
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Backes S, Garg SG, Becker L, Peleh V, Glockshuber R, Gould SB, Herrmann JM. Development of the Mitochondrial Intermembrane Space Disulfide Relay Represents a Critical Step in Eukaryotic Evolution. Mol Biol Evol 2019; 36:742-756. [PMID: 30668797 DOI: 10.1093/molbev/msz011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The mitochondrial intermembrane space evolved from the bacterial periplasm. Presumably as a consequence of their common origin, most proteins of these compartments are stabilized by structural disulfide bonds. The molecular machineries that mediate oxidative protein folding in bacteria and mitochondria, however, appear to share no common ancestry. Here we tested whether the enzymes Erv1 and Mia40 of the yeast mitochondrial disulfide relay could be functionally replaced by corresponding components of other compartments. We found that the sulfhydryl oxidase Erv1 could be replaced by the Ero1 oxidase or the protein disulfide isomerase from the endoplasmic reticulum, however at the cost of respiration deficiency. In contrast to Erv1, the mitochondrial oxidoreductase Mia40 proved to be indispensable and could not be replaced by thioredoxin-like enzymes, including the cytoplasmic reductase thioredoxin, the periplasmic dithiol oxidase DsbA, and Pdi1. From our studies we conclude that the profound inertness against glutathione, its slow oxidation kinetics and its high affinity to substrates renders Mia40 a unique and essential component of mitochondrial biogenesis. Evidently, the development of a specific mitochondrial disulfide relay system represented a crucial step in the evolution of the eukaryotic cell.
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Affiliation(s)
- Sandra Backes
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Sriram G Garg
- Molecular Evolution, Heinrich-Heine-University of Dusseldorf, Dusseldorf, Germany
| | - Laura Becker
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Valentina Peleh
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Rudi Glockshuber
- Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
| | - Sven B Gould
- Molecular Evolution, Heinrich-Heine-University of Dusseldorf, Dusseldorf, Germany
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23
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Meyer AJ, Riemer J, Rouhier N. Oxidative protein folding: state-of-the-art and current avenues of research in plants. THE NEW PHYTOLOGIST 2019; 221:1230-1246. [PMID: 30230547 DOI: 10.1111/nph.15436] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Contents Summary 1230 I. Introduction 1230 II. Formation and isomerization of disulfides in the ER and the Golgi apparatus 1231 III. The disulfide relay in the mitochondrial intermembrane space: why are plants different? 1236 IV. Disulfide bond formation on luminal proteins in thylakoids 1240 V. Conclusion 1242 Acknowledgements 1242 References 1242 SUMMARY: Disulfide bonds are post-translational modifications crucial for the structure and function of thousands of proteins. Their formation and isomerization, referred to as oxidative folding, require specific protein machineries found in oxidizing subcellular compartments, namely the endoplasmic reticulum and the associated endomembrane system, the intermembrane space of mitochondria and the thylakoid lumen of chloroplasts. At least one protein component is required for transferring electrons from substrate proteins to an acceptor that is usually molecular oxygen. For oxidation reactions, incoming reduced substrates are oxidized by thiol-oxidoreductase proteins (or domains in case of chimeric proteins), which are usually themselves oxidized by a single thiol oxidase, the enzyme generating disulfide bonds de novo. By contrast, the description of the molecular actors and pathways involved in proofreading and isomerization of misfolded proteins, which require a tightly controlled redox balance, lags behind. Herein we provide a general overview of the knowledge acquired on the systems responsible for oxidative protein folding in photosynthetic organisms, highlighting their particularities compared to other eukaryotes. Current research challenges are discussed including the importance and specificity of these oxidation systems in the context of the existence of reducing systems in the same compartments.
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Affiliation(s)
- Andreas J Meyer
- INRES-Chemical Signalling, University of Bonn, 53113, Bonn, Germany
| | - Jan Riemer
- Institute of Biochemistry, University of Cologne, 50674, Cologne, Germany
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24
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Augmenter of liver regeneration: Essential for growth and beyond. Cytokine Growth Factor Rev 2018; 45:65-80. [PMID: 30579845 DOI: 10.1016/j.cytogfr.2018.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/12/2018] [Accepted: 12/14/2018] [Indexed: 12/11/2022]
Abstract
Liver regeneration is a well-orchestrated process that is triggered by tissue loss due to trauma or surgical resection and by hepatocellular death induced by toxins or viral infections. Due to the central role of the liver for body homeostasis, intensive research was conducted to identify factors that might contribute to hepatic growth and regeneration. Using a model of partial hepatectomy several factors including cytokines and growth factors that regulate this process were discovered. Among them, a protein was identified to specifically support liver regeneration and therefore was named ALR (Augmenter of Liver Regeneration). ALR protein is encoded by GFER (growth factor erv1-like) gene and can be regulated by various stimuli. ALR is expressed in different tissues in three isoforms which are associated with multiple functions: The long forms of ALR were found in the inner-mitochondrial space (IMS) and the cytosol. Mitochondrial ALR (23 kDa) was shown to cooperate with Mia40 to insure adequate protein folding during import into IMS. On the other hand short form ALR, located mainly in the cytosol, was attributed with anti-apoptotic and anti-oxidative properties as well as its inflammation and metabolism modulating effects. Although a considerable amount of work has been devoted to summarizing the knowledge on ALR, an investigation of ALR expression in different organs (location, subcellular localization) as well as delineation between the isoforms and function of ALR is still missing. This review provides a comprehensive evaluation of ALR structure and expression of different ALR isoforms. Furthermore, we highlight the functional role of endogenously expressed and exogenously applied ALR, as well as an analysis of the clinical importance of ALR, with emphasis on liver disease and in vivo models, as well as the consequences of mutations in the GFER gene.
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Sokol AM, Uszczynska-Ratajczak B, Collins MM, Bazala M, Topf U, Lundegaard PR, Sugunan S, Guenther S, Kuenne C, Graumann J, Chan SSL, Stainier DYR, Chacinska A. Loss of the Mia40a oxidoreductase leads to hepato-pancreatic insufficiency in zebrafish. PLoS Genet 2018; 14:e1007743. [PMID: 30457989 PMCID: PMC6245507 DOI: 10.1371/journal.pgen.1007743] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 10/05/2018] [Indexed: 02/07/2023] Open
Abstract
Development and function of tissues and organs are powered by the activity of mitochondria. In humans, inherited genetic mutations that lead to progressive mitochondrial pathology often manifest during infancy and can lead to death, reflecting the indispensable nature of mitochondrial biogenesis and function. Here, we describe a zebrafish mutant for the gene mia40a (chchd4a), the life-essential homologue of the evolutionarily conserved Mia40 oxidoreductase which drives the biogenesis of cysteine-rich mitochondrial proteins. We report that mia40a mutant animals undergo progressive cellular respiration defects and develop enlarged mitochondria in skeletal muscles before their ultimate death at the larval stage. We generated a deep transcriptomic and proteomic resource that allowed us to identify abnormalities in the development and physiology of endodermal organs, in particular the liver and pancreas. We identify the acinar cells of the exocrine pancreas to be severely affected by mutations in the MIA pathway. Our data contribute to a better understanding of the molecular, cellular and organismal effects of mitochondrial deficiency, important for the accurate diagnosis and future treatment strategies of mitochondrial diseases. Mitochondrial pathologies which result from mutations in the nuclear DNA remain incurable and often lead to death. As mitochondria play various roles in cellular and tissue-specific contexts, the symptoms of mitochondrial pathologies can differ between patients. Thus, diagnosis and treatment of mitochondrial disorders remain challenging. To enhance this, the generation of new models that explore and define the consequences of mitochondria insufficiencies is of central importance. Here, we present a mia40a zebrafish mutant as a model for mitochondrial dysfunction, caused by an imbalance in mitochondrial protein biogenesis. This mutant shares characteristics with existing reports on mitochondria dysfunction, and has led us to identify novel phenotypes such as enlarged mitochondrial clusters in skeletal muscles. In addition, our transcriptomics and proteomics data contribute important findings to the existing knowledge on how faulty mitochondria impinge on vertebrate development in molecular, tissue and organ specific contexts.
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Affiliation(s)
- Anna M. Sokol
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
- Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
- * E-mail: (AMS); (AC)
| | | | - Michelle M. Collins
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Michal Bazala
- International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Ulrike Topf
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Pia R. Lundegaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sreedevi Sugunan
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Stefan Guenther
- Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Carsten Kuenne
- Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Johannes Graumann
- Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Sherine S. L. Chan
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Didier Y. R. Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Agnieszka Chacinska
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- * E-mail: (AMS); (AC)
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26
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Habich M, Salscheider SL, Riemer J. Cysteine residues in mitochondrial intermembrane space proteins: more than just import. Br J Pharmacol 2018; 176:514-531. [PMID: 30129023 DOI: 10.1111/bph.14480] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/20/2018] [Accepted: 06/26/2018] [Indexed: 12/13/2022] Open
Abstract
The intermembrane space (IMS) is a very small mitochondrial sub-compartment with critical relevance for many cellular processes. IMS proteins fulfil important functions in transport of proteins, lipids, metabolites and metal ions, in signalling, in metabolism and in defining the mitochondrial ultrastructure. Our understanding of the IMS proteome has become increasingly refined although we still lack information on the identity and function of many of its proteins. One characteristic of many IMS proteins are conserved cysteines. Different post-translational modifications of these cysteine residues can have critical roles in protein function, localization and/or stability. The close localization to different ROS-producing enzyme systems, a dedicated machinery for oxidative protein folding, and a unique equipment with antioxidative systems, render the careful balancing of the redox and modification states of the cysteine residues, a major challenge in the IMS. In this review, we discuss different functions of human IMS proteins, the involvement of cysteine residues in these functions, the consequences of cysteine modifications and the consequences of cysteine mutations or defects in the machinery for disulfide bond formation in terms of human health. LINKED ARTICLES: This article is part of a themed section on Chemical Biology of Reactive Sulfur Species. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.4/issuetoc.
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Affiliation(s)
- Markus Habich
- Department of Chemistry, Institute of Biochemistry, Redox Biochemistry, University of Cologne, Cologne, Germany
| | - Silja Lucia Salscheider
- Department of Chemistry, Institute of Biochemistry, Redox Biochemistry, University of Cologne, Cologne, Germany
| | - Jan Riemer
- Department of Chemistry, Institute of Biochemistry, Redox Biochemistry, University of Cologne, Cologne, Germany
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27
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Erdogan AJ, Ali M, Habich M, Salscheider SL, Schu L, Petrungaro C, Thomas LW, Ashcroft M, Leichert LI, Roma LP, Riemer J. The mitochondrial oxidoreductase CHCHD4 is present in a semi-oxidized state in vivo. Redox Biol 2018; 17:200-206. [PMID: 29704824 PMCID: PMC6007816 DOI: 10.1016/j.redox.2018.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 03/22/2018] [Indexed: 11/30/2022] Open
Abstract
Disulfide formation in the mitochondrial intermembrane space is an essential process catalyzed by a disulfide relay machinery. In mammalian cells, the key enzyme in this machinery is the oxidoreductase CHCHD4/Mia40. Here, we determined the in vivo CHCHD4 redox state, which is the major determinant of its cellular activity. We found that under basal conditions, endogenous CHCHD4 redox state in cultured cells and mouse tissues was predominantly oxidized, however, degrees of oxidation in different tissues varied from 70% to 90% oxidized. To test whether differences in the ratio between CHCHD4 and ALR might explain tissue-specific differences in the CHCHD4 redox state, we determined the molar ratio of both proteins in different mouse tissues. Surprisingly, ALR is superstoichiometric over CHCHD4 in most tissues. However, the levels of CHCHD4 and the ratio of ALR over CHCHD4 appear to correlate only weakly with the redox state, and although ALR is present in superstoichiometric amounts, it does not lead to fully oxidized CHCHD4.
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Affiliation(s)
- Alican J Erdogan
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany
| | - Muna Ali
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany; Department of Biology, Cellular Biochemistry, University of Kaiserslautern, Erwin-Schroedinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Markus Habich
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany
| | - Silja L Salscheider
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany
| | - Laura Schu
- Department of Biology, Cellular Biochemistry, University of Kaiserslautern, Erwin-Schroedinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Carmelina Petrungaro
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany
| | - Luke W Thomas
- Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Margaret Ashcroft
- Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Lars I Leichert
- Institute for Biochemistry and Pathobiochemistry - Microbial Biochemistry, Ruhr-Universität Bochum, 44797 Bochum, Germany
| | - Leticia Prates Roma
- Biophysics Department, Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Saar, Germany
| | - Jan Riemer
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany.
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28
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Gupta P, Venugopal SK. Augmenter of liver regeneration: A key protein in liver regeneration and pathophysiology. Hepatol Res 2018; 48:587-596. [PMID: 29633440 DOI: 10.1111/hepr.13077] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/10/2018] [Accepted: 03/29/2018] [Indexed: 12/22/2022]
Abstract
Liver is constantly exposed to pathogens, viruses, chemicals, and toxins, and several of them cause injury, leading to the loss of liver mass and sometimes resulting in cirrhosis and cancer. Under physiological conditions, liver can regenerate if the loss of cells is less than the proliferation of hepatocytes. If the loss is more than the proliferation, the radical treatment available is liver transplantation. Due to this reason, the search for an alternative therapeutic agent has been the focus of liver research. Liver regeneration is regulated by several growth factors; one of the key factors is augmenter of liver regeneration (ALR). Involvement of ALR has been reported in crucial processes such as oxidative phosphorylation, maintenance of mitochondria and mitochondrial biogenesis, and regulation of autophagy and cell proliferation. Augmenter of liver regeneration has been observed to be involved in liver regeneration by not only overcoming cell cycle inhibition but by maintaining the stem cell pool as well. These observations have created curiosity regarding the possible role of ALR in maintenance of liver health. Thus, this review brings a concise presentation of the work done in areas exploring the role of ALR in normal liver physiology and in liver health maintenance by fighting liver diseases, such as liver failure, non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, viral infections, cirrhosis, and hepatocellular carcinoma.
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Affiliation(s)
- Parul Gupta
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
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29
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Kowalski L, Bragoszewski P, Khmelinskii A, Glow E, Knop M, Chacinska A. Determinants of the cytosolic turnover of mitochondrial intermembrane space proteins. BMC Biol 2018; 16:66. [PMID: 29929515 PMCID: PMC6013907 DOI: 10.1186/s12915-018-0536-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 05/25/2018] [Indexed: 12/31/2022] Open
Abstract
Background The proteome of mitochondria comprises mostly proteins that originate as precursors in the cytosol. Before import into the organelle, such proteins are exposed to cytosolic quality control mechanisms. Multiple lines of evidence indicate a significant contribution of the major cytosolic protein degradation machinery, the ubiquitin-proteasome system, to the quality control of mitochondrial proteins. Proteins that are directed to the mitochondrial intermembrane space (IMS) exemplify an entire class of mitochondrial proteins regulated by proteasomal degradation. However, little is known about how these proteins are selected for degradation. Results The present study revealed the heterogeneous cytosolic stability of IMS proteins. Using a screening approach, we found that different cytosolic factors are responsible for the degradation of specific IMS proteins, with no single common factor involved in the degradation of all IMS proteins. We found that the Cox12 protein is rapidly degraded when localized to the cytosol, thus providing a sensitive experimental model. Using Cox12, we found that lysine residues but not conserved cysteine residues are among the degron features important for protein ubiquitination. We observed the redundancy of ubiquitination components, with significant roles of Ubc4 E2 ubiquitin-conjugating enzyme and Rsp5 E3 ubiquitin ligase. The amount of ubiquitinated Cox12 was inversely related to mitochondrial import efficiency. Importantly, we found that precursor protein ubiquitination blocks its import into mitochondria. Conclusions The present study confirms the involvement of ubiquitin-proteasome system in the quality control of mitochondrial IMS proteins in the cytosol. Notably, ubiquitination of IMS proteins prohibits their import into mitochondria. Therefore, ubiquitination directly affects the availability of precursor proteins for organelle biogenesis. Importantly, despite their structural similarities, IMS proteins are not selected for degradation in a uniform way. Instead, specific IMS proteins rely on discrete components of the ubiquitination machinery to mediate their clearance by the proteasome. Electronic supplementary material The online version of this article (10.1186/s12915-018-0536-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lukasz Kowalski
- Centre of New Technologies, University of Warsaw, Warsaw, Poland.,International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Piotr Bragoszewski
- Centre of New Technologies, University of Warsaw, Warsaw, Poland. .,International Institute of Molecular and Cell Biology, Warsaw, Poland.
| | - Anton Khmelinskii
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany.,Institute of Molecular Biology (IMB), Mainz, Germany
| | - Edyta Glow
- International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Michael Knop
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany.,Deutsches Krebsforschungszentrum (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Agnieszka Chacinska
- Centre of New Technologies, University of Warsaw, Warsaw, Poland. .,International Institute of Molecular and Cell Biology, Warsaw, Poland.
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30
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A single-cysteine mutant and chimeras of essential Leishmania Erv can complement the loss of Erv1 but not of Mia40 in yeast. Redox Biol 2017; 15:363-374. [PMID: 29310075 PMCID: PMC5760468 DOI: 10.1016/j.redox.2017.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/17/2017] [Accepted: 12/21/2017] [Indexed: 11/21/2022] Open
Abstract
Mia40/CHCHD4 and Erv1/ALR are essential for oxidative protein folding in the mitochondrial intermembrane space of yeast and mammals. In contrast, many protists, including important apicomplexan and kinetoplastid parasites, lack Mia40. Furthermore, the Erv homolog of the model parasite Leishmania tarentolae (LtErv) was shown to be incompatible with Saccharomyces cerevisiae Mia40 (ScMia40). Here we addressed structure-function relationships of ScErv1 and LtErv as well as their compatibility with the oxidative protein folding system in yeast using chimeric, truncated, and mutant Erv constructs. Chimeras between the N-terminal arm of ScErv1 and a variety of truncated LtErv constructs were able to rescue yeast cells that lack ScErv1. Yeast cells were also viable when only a single cysteine residue was replaced in LtErvC17S. Thus, the presence and position of the C-terminal arm and the kinetoplastida-specific second (KISS) domain of LtErv did not interfere with its functionality in the yeast system, whereas a relatively conserved cysteine residue before the flavodomain rendered LtErv incompatible with ScMia40. The question whether parasite Erv homologs might also exert the function of Mia40 was addressed in another set of complementation assays. However, neither the KISS domain nor other truncated or mutant LtErv constructs were able to rescue yeast cells that lack ScMia40. The general relevance of Erv and its candidate substrate small Tim1 was analyzed for the related parasite L. infantum. Repeated unsuccessful knockout attempts suggest that both genes are essential in this human pathogen and underline the potential of mitochondrial protein import pathways for future intervention strategies.
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31
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Peleh V, Zannini F, Backes S, Rouhier N, Herrmann JM. Erv1 of Arabidopsis thaliana can directly oxidize mitochondrial intermembrane space proteins in the absence of redox-active Mia40. BMC Biol 2017; 15:106. [PMID: 29117860 PMCID: PMC5679390 DOI: 10.1186/s12915-017-0445-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/19/2017] [Indexed: 11/20/2022] Open
Abstract
Background Many proteins of the mitochondrial intermembrane space (IMS) contain structural disulfide bonds formed by the mitochondrial disulfide relay. In fungi and animals, the sulfhydryl oxidase Erv1 ‘generates’ disulfide bonds that are passed on to the oxidoreductase Mia40, which oxidizes substrate proteins. A different structural organization of plant Erv1 proteins compared to that of animal and fungal orthologs was proposed to explain its inability to complement the corresponding yeast mutant. Results Herein, we have revisited the biochemical and functional properties of Arabidopsis thaliana Erv1 by both in vitro reconstituted activity assays and complementation of erv1 and mia40 yeast mutants. These mutants were viable, however, they showed severe defects in the biogenesis of IMS proteins. The plant Erv1 was unable to oxidize yeast Mia40 and rather even blocked its activity. Nevertheless, it was able to mediate the import and folding of mitochondrial proteins. Conclusions We observed that plant Erv1, unlike its homologs in fungi and animals, can promote protein import and oxidative protein folding in the IMS independently of the oxidoreductase Mia40. In accordance to the absence of Mia40 in many protists, our study suggests that the mitochondrial disulfide relay evolved in a stepwise reaction from an Erv1-only system to which Mia40 was added in order to improve substrate specificity. The mitochondrial disulfide relay evolved in a step-wise manner from an Erv1-only system. ![]()
Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0445-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Valentina Peleh
- Cell Biology, University of Kaiserslautern, Erwin-Schrödinger-Strasse 13, 67663, Kaiserslautern, Germany
| | - Flavien Zannini
- Unité Mixte de Recherches 1136 Interactions Arbres-Microorganismes, Université de Lorraine/INRA, Faculté des sciences et technologies, 54500 Vandoeuvre-lès-Nancy, Nancy, France
| | - Sandra Backes
- Cell Biology, University of Kaiserslautern, Erwin-Schrödinger-Strasse 13, 67663, Kaiserslautern, Germany
| | - Nicolas Rouhier
- Unité Mixte de Recherches 1136 Interactions Arbres-Microorganismes, Université de Lorraine/INRA, Faculté des sciences et technologies, 54500 Vandoeuvre-lès-Nancy, Nancy, France.
| | - Johannes M Herrmann
- Cell Biology, University of Kaiserslautern, Erwin-Schrödinger-Strasse 13, 67663, Kaiserslautern, Germany.
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32
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Schorr S, van der Laan M. Integrative functions of the mitochondrial contact site and cristae organizing system. Semin Cell Dev Biol 2017; 76:191-200. [PMID: 28923515 DOI: 10.1016/j.semcdb.2017.09.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/13/2017] [Accepted: 09/14/2017] [Indexed: 12/23/2022]
Abstract
Mitochondria are complex double-membrane-bound organelles of eukaryotic cells that function as energy-converting powerhouses, metabolic factories and signaling centers. The outer membrane controls the exchange of material and information with other cellular compartments. The inner membrane provides an extended, highly folded surface for selective transport and energy-coupling reactions. It can be divided into an inner boundary membrane and tubular or lamellar cristae membranes that accommodate the oxidative phosphorylation units. Outer membrane, inner boundary membrane and cristae come together at crista junctions, where the mitochondrial contact site and cristae organizing system (MICOS) acts as a membrane-shaping and -connecting scaffold. This peculiar architecture is of pivotal importance for multiple mitochondrial functions. Many elaborate studies in the past years have shed light on the subunit composition and organization of MICOS. In this review article, we summarize these insights and then move on to discuss exciting recent discoveries on the integrative functions of MICOS. Multi-faceted connections to other major players of mitochondrial biogenesis and physiology, like the protein import machineries, the oxidative phosphorylation system, carrier proteins and phospholipid biosynthesis enzymes, are currently emerging. Therefore, we propose that MICOS acts as a central hub in mitochondrial membrane architecture and functionality.
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Affiliation(s)
- Stefan Schorr
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, School of Medicine, 66421, Homburg, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, School of Medicine, 66421, Homburg, Germany.
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Cardenas-Rodriguez M, Tokatlidis K. Cytosolic redox components regulate protein homeostasis via additional localisation in the mitochondrial intermembrane space. FEBS Lett 2017; 591:2661-2670. [PMID: 28746987 PMCID: PMC5601281 DOI: 10.1002/1873-3468.12766] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 07/15/2017] [Accepted: 07/21/2017] [Indexed: 12/31/2022]
Abstract
Oxidative protein folding is confined to the bacterial periplasm, endoplasmic reticulum and the mitochondrial intermembrane space. Maintaining a redox balance requires the presence of reductive pathways. The major thiol‐reducing pathways engage the thioredoxin and the glutaredoxin systems which are involved in removal of oxidants, protein proofreading and folding. Alterations in redox balance likely affect the flux of these redox pathways and are related to ageing and diseases such as neurodegenerative disorders and cancer. Here, we first review the well‐studied oxidative and reductive processes in the bacterial periplasm and the endoplasmic reticulum, and then discuss the less understood process in the mitochondrial intermembrane space, highlighting its importance for the proper function of the cell.
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Affiliation(s)
- Mauricio Cardenas-Rodriguez
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Kostas Tokatlidis
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
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Abstract
Cysteine thiols are among the most reactive functional groups in proteins, and their pairing in disulfide linkages is a common post-translational modification in proteins entering the secretory pathway. This modest amino acid alteration, the mere removal of a pair of hydrogen atoms from juxtaposed cysteine residues, contrasts with the substantial changes that characterize most other post-translational reactions. However, the wide variety of proteins that contain disulfides, the profound impact of cross-linking on the behavior of the protein polymer, the numerous and diverse players in intracellular pathways for disulfide formation, and the distinct biological settings in which disulfide bond formation can take place belie the simplicity of the process. Here we lay the groundwork for appreciating the mechanisms and consequences of disulfide bond formation in vivo by reviewing chemical principles underlying cysteine pairing and oxidation. We then show how enzymes tune redox-active cofactors and recruit oxidants to improve the specificity and efficiency of disulfide formation. Finally, we discuss disulfide bond formation in a cellular context and identify important principles that contribute to productive thiol oxidation in complex, crowded, dynamic environments.
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Affiliation(s)
- Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Colin Thorpe
- Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States
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35
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Protein trafficking in the mitochondrial intermembrane space: mechanisms and links to human disease. Biochem J 2017; 474:2533-2545. [PMID: 28701417 PMCID: PMC5509380 DOI: 10.1042/bcj20160627] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 05/03/2017] [Accepted: 05/09/2017] [Indexed: 01/20/2023]
Abstract
Mitochondria fulfill a diverse range of functions in cells including oxygen metabolism, homeostasis of inorganic ions and execution of apoptosis. Biogenesis of mitochondria relies on protein import pathways that are ensured by dedicated multiprotein translocase complexes localized in all sub-compartments of these organelles. The key components and pathways involved in protein targeting and assembly have been characterized in great detail over the last three decades. This includes the oxidative folding machinery in the intermembrane space, which contributes to the redox-dependent control of proteostasis. Here, we focus on several components of this system and discuss recent evidence suggesting links to human proteopathy.
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36
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Cesselli D, Aleksova A, Sponga S, Cervellin C, Di Loreto C, Tell G, Beltrami AP. Cardiac Cell Senescence and Redox Signaling. Front Cardiovasc Med 2017; 4:38. [PMID: 28612009 PMCID: PMC5447053 DOI: 10.3389/fcvm.2017.00038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/10/2017] [Indexed: 12/12/2022] Open
Abstract
Aging is characterized by a progressive loss of the ability of the organism to cope with stressors and to repair tissue damage. As a result, chronic diseases, including cardiovascular disease, increase their prevalence with aging, underlining the existence of common mechanisms that lead to frailty and age-related diseases. In this frame, the progressive decline of the homeostatic and reparative function of primitive cells has been hypothesized to play a major role in the evolution of cardiac pathology to heart failure. Although initially it was believed that reactive oxygen species (ROS) were produced in an unregulated manner as a byproduct of cellular metabolism, causing macromolecular damage and aging, accumulating evidence indicate the major role played by redox signaling in physiology. Aim of this review is to critically revise evidence linking ROS to cell senescence and aging and to provide evidence of the primary role played by redox signaling, with a particular emphasis on the multifunctional protein APE1/Ref in stem cell biology. Finally, we will discuss evidence supporting the role of redox signaling in cardiovascular cells.
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Affiliation(s)
| | - Aneta Aleksova
- Cardiovascular Department, Azienda Sanitaria Universitaria Integrata di Trieste, University of Trieste, Trieste, Italy
| | - Sandro Sponga
- Cardiothoracic Surgery, Azienda Sanitaria Universitaria Integrata di Udine, Udine, Italy
| | | | | | - Gianluca Tell
- Department of Medicine, University of Udine, Udine, Italy
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37
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Manganas P, MacPherson L, Tokatlidis K. Oxidative protein biogenesis and redox regulation in the mitochondrial intermembrane space. Cell Tissue Res 2016; 367:43-57. [PMID: 27632163 PMCID: PMC5203823 DOI: 10.1007/s00441-016-2488-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/05/2016] [Indexed: 12/22/2022]
Abstract
Mitochondria are organelles that play a central role in cellular metabolism, as they are responsible for processes such as iron/sulfur cluster biogenesis, respiration and apoptosis. Here, we describe briefly the various protein import pathways for sorting of mitochondrial proteins into the different subcompartments, with an emphasis on the targeting to the intermembrane space. The discovery of a dedicated redox-controlled pathway in the intermembrane space that links protein import to oxidative protein folding raises important questions on the redox regulation of this process. We discuss the salient features of redox regulation in the intermembrane space and how such mechanisms may be linked to the more general redox homeostasis balance that is crucial not only for normal cell physiology but also for cellular dysfunction.
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Affiliation(s)
- Phanee Manganas
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Lisa MacPherson
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Kostas Tokatlidis
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Mitochondrial disulfide relay and its substrates: mechanisms in health and disease. Cell Tissue Res 2016; 367:59-72. [DOI: 10.1007/s00441-016-2481-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/18/2016] [Indexed: 01/06/2023]
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Nuebel E, Manganas P, Tokatlidis K. Orphan proteins of unknown function in the mitochondrial intermembrane space proteome: New pathways and metabolic cross-talk. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2613-2623. [PMID: 27425144 PMCID: PMC5404111 DOI: 10.1016/j.bbamcr.2016.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 07/07/2016] [Accepted: 07/12/2016] [Indexed: 12/14/2022]
Abstract
The mitochondrial intermembrane space (IMS) is involved in protein transport, lipid homeostasis and metal ion exchange, while further acting in signalling pathways such as apoptosis. Regulation of these processes involves protein modifications, as well as stress-induced import or release of proteins and other signalling molecules. Even though the IMS is the smallest sub-compartment of mitochondria, its redox state seems to be tightly regulated. However, the way in which this compartment participates in the cross-talk between the multiple organelles and the cytosol is far from understood. Here we focus on newly identified IMS proteins that may represent future challenges in mitochondrial research. We present an overview of the import pathways, the recently discovered new components of the IMS proteome and how these relate to key aspects of cell signalling and progress made in stem cell and cancer research. A brief overview of the classic mitochondrial import pathways is featured Recent studies assigning a number of new proteins to the mitochondrial IMS are discussed Analysis of the expanded IMS proteomes can provide insights into organelle cross-talk and signalling pathways
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Affiliation(s)
- Esther Nuebel
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Phanee Manganas
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Kostas Tokatlidis
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK.
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40
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Peleh V, Cordat E, Herrmann JM. Mia40 is a trans-site receptor that drives protein import into the mitochondrial intermembrane space by hydrophobic substrate binding. eLife 2016; 5. [PMID: 27343349 PMCID: PMC4951193 DOI: 10.7554/elife.16177] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/24/2016] [Indexed: 11/13/2022] Open
Abstract
Many proteins of the mitochondrial IMS contain conserved cysteines that are oxidized to disulfide bonds during their import. The conserved IMS protein Mia40 is essential for the oxidation and import of these proteins. Mia40 consists of two functional elements: an N-terminal cysteine-proline-cysteine motif conferring substrate oxidation, and a C-terminal hydrophobic pocket for substrate binding. In this study, we generated yeast mutants to dissect both Mia40 activities genetically and biochemically. Thereby we show that the substrate-binding domain of Mia40 is both necessary and sufficient to promote protein import, indicating that trapping by Mia40 drives protein translocation. An oxidase-deficient Mia40 mutant is inviable, but can be partially rescued by the addition of the chemical oxidant diamide. Our results indicate that Mia40 predominantly serves as a trans-site receptor of mitochondria that binds incoming proteins via hydrophobic interactions thereby mediating protein translocation across the outer membrane by a ‘holding trap’ rather than a ‘folding trap’ mechanism. DOI:http://dx.doi.org/10.7554/eLife.16177.001 Human, yeast and other eukaryotic cells contain compartments called mitochondria that perform several vital tasks, including supplying the cell with energy. Each mitochondrion is surrounded by an inner and an outer membrane, which are separated by an intermembrane space that contains a host of molecules, including proteins. Intermembrane space proteins are made in the cytosol before being transported into the intermembrane space through pores in the mitochondrion’s outer membrane. Many of these proteins have the ability to form disulfide bonds within their structures, which help the proteins to fold and assemble correctly, but they only acquire these bonds once they have entered the intermembrane space. An enzyme called Mia40 sits inside the intermembrane space and helps other proteins to fold correctly. This Mia40-induced folding had been suggested to help proteins to move into the intermembrane space. Mia40 contains two important regions: one region acts as an enzyme and adds disulfide bonds to other proteins, and the other region binds to the intermembrane space proteins. Peleh et al. have now generated versions of Mia40 that lack one or the other of these regions in yeast cells, and then tested to see if these mutants could drive proteins across the outer membrane of mitochondria. The results show that it is the ability of Mia40 to bind proteins – and not its enzyme activity – that is essential for importing proteins into the intermembrane space. As disulfide bond formation is not critical for importing proteins into the intermembrane space, future studies could test whether Mia40 also helps to transport proteins that cannot form disulfide bonds. Presumably, Mia40 has a much broader relevance for importing mitochondrial proteins than was previously thought. DOI:http://dx.doi.org/10.7554/eLife.16177.002
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Affiliation(s)
- Valentina Peleh
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
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41
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Chatzi A, Manganas P, Tokatlidis K. Oxidative folding in the mitochondrial intermembrane space: A regulated process important for cell physiology and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1298-306. [PMID: 27033519 PMCID: PMC5405047 DOI: 10.1016/j.bbamcr.2016.03.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 01/05/2023]
Abstract
Mitochondria are fundamental organelles with a complex internal architecture that fulfill important diverse functions including iron–sulfur cluster assembly and cell respiration. Intense work for more than 30 years has identified the key protein import components and the pathways involved in protein targeting and assembly. More recently, oxidative folding has been discovered as one important mechanism for mitochondrial proteostasis whilst several human disorders have been linked to this pathway. We describe the molecular components of this pathway in view of their putative redox regulation and we summarize available evidence on the connections of these pathways to human disorders. Mitochondria are the cell center of iron–sulfur cluster assembly and cell respiration. The MIA pathway has recently been linked to Fe/S pathways, Ca2 + uptake and apoptosis. Mitochondria along with the ER and peroxisomes are major sources of ROS. Many diseases have been linked to mitochondrial dysfunction.
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Affiliation(s)
- Afroditi Chatzi
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Phanee Manganas
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Kostas Tokatlidis
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, UK; Department of Materials Science and Technology, University of Crete, Heraklion, Crete, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Crete, Greece.
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42
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Petrungaro C, Zimmermann KM, Küttner V, Fischer M, Dengjel J, Bogeski I, Riemer J. The Ca(2+)-Dependent Release of the Mia40-Induced MICU1-MICU2 Dimer from MCU Regulates Mitochondrial Ca(2+) Uptake. Cell Metab 2015; 22:721-33. [PMID: 26387864 DOI: 10.1016/j.cmet.2015.08.019] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 05/24/2015] [Accepted: 08/14/2015] [Indexed: 12/13/2022]
Abstract
The essential oxidoreductase Mia40/CHCHD4 mediates disulfide bond formation and protein folding in the mitochondrial intermembrane space. Here, we investigated the interactome of Mia40 thereby revealing links between thiol-oxidation and apoptosis, energy metabolism, and Ca(2+) signaling. Among the interaction partners of Mia40 is MICU1-the regulator of the mitochondrial Ca(2+) uniporter (MCU), which transfers Ca(2+) across the inner membrane. We examined the biogenesis of MICU1 and find that Mia40 introduces an intermolecular disulfide bond that links MICU1 and its inhibitory paralog MICU2 in a heterodimer. Absence of this disulfide bond results in increased receptor-induced mitochondrial Ca(2+) uptake. In the presence of the disulfide bond, MICU1-MICU2 heterodimer binding to MCU is controlled by Ca(2+) levels: the dimer associates with MCU at low levels of Ca(2+) and dissociates upon high Ca(2+) concentrations. Our findings support a model in which mitochondrial Ca(2+) uptake is regulated by a Ca(2+)-dependent remodeling of the uniporter complex.
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Affiliation(s)
- Carmelina Petrungaro
- Cellular Biochemistry, University of Kaiserslautern, Erwin-Schroedinger-Str. 13, 67663 Kaiserslautern, Germany; Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47, 50674 Cologne, Germany
| | - Katharina M Zimmermann
- Department of Biophysics, CIPMM, School of Medicine, University of Saarland, 66421, Homburg, Germany
| | - Victoria Küttner
- Department of Dermatology, Medical Center, Freiburg Institute for Advanced Studies, BIOSS Centre for Biological Signaling Studies, ZBSA Center for Biological Systems Analysis, University of Freiburg, Habsburgerstr. 49, 79104 Freiburg, Germany
| | - Manuel Fischer
- Cellular Biochemistry, University of Kaiserslautern, Erwin-Schroedinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Jörn Dengjel
- Department of Dermatology, Medical Center, Freiburg Institute for Advanced Studies, BIOSS Centre for Biological Signaling Studies, ZBSA Center for Biological Systems Analysis, University of Freiburg, Habsburgerstr. 49, 79104 Freiburg, Germany
| | - Ivan Bogeski
- Department of Biophysics, CIPMM, School of Medicine, University of Saarland, 66421, Homburg, Germany
| | - Jan Riemer
- Cellular Biochemistry, University of Kaiserslautern, Erwin-Schroedinger-Str. 13, 67663 Kaiserslautern, Germany; Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47, 50674 Cologne, Germany.
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43
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The Oxidation Status of Mic19 Regulates MICOS Assembly. Mol Cell Biol 2015; 35:4222-37. [PMID: 26416881 PMCID: PMC4648825 DOI: 10.1128/mcb.00578-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/04/2015] [Indexed: 02/04/2023] Open
Abstract
The function of mitochondria depends on the proper organization of mitochondrial membranes. The morphology of the inner membrane is regulated by the recently identified mitochondrial contact site and crista organizing system (MICOS) complex. MICOS mutants exhibit alterations in crista formation, leading to mitochondrial dysfunction. However, the mechanisms that underlie MICOS regulation remain poorly understood. MIC19, a peripheral protein of the inner membrane and component of the MICOS complex, was previously reported to be required for the proper function of MICOS in maintaining the architecture of the inner membrane. Here, we show that human and Saccharomyces cerevisiae MIC19 proteins undergo oxidation in mitochondria and require the mitochondrial intermembrane space assembly (MIA) pathway, which couples the oxidation and import of mitochondrial intermembrane space proteins for mitochondrial localization. Detailed analyses identified yeast Mic19 in two different redox forms. The form that contains an intramolecular disulfide bond is bound to Mic60 of the MICOS complex. Mic19 oxidation is not essential for its integration into the MICOS complex but plays a role in MICOS assembly and the maintenance of the proper inner membrane morphology. These findings suggest that Mic19 is a redox-dependent regulator of MICOS function.
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44
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Millán C, Sammito M, Garcia-Ferrer I, Goulas T, Sheldrick GM, Usón I. Combining phase information in reciprocal space for molecular replacement with partial models. ACTA ACUST UNITED AC 2015; 71:1931-45. [PMID: 26327383 DOI: 10.1107/s1399004715013127] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 07/08/2015] [Indexed: 11/10/2022]
Abstract
ARCIMBOLDO allows ab initio phasing of macromolecular structures below atomic resolution by exploiting the location of small model fragments combined with density modification in a multisolution frame. The model fragments can be either secondary-structure elements predicted from the sequence or tertiary-structure fragments. The latter can be derived from libraries of typical local folds or from related structures, such as a low-homology model that is unsuccessful in molecular replacement. In all ARCIMBOLDO applications, fragments are searched for sequentially. Correct partial solutions obtained after each fragment-search stage but lacking the necessary phasing power can, if combined, succeed. Here, an analysis is presented of the clustering of partial solutions in reciprocal space and of its application to a set of different cases. In practice, the task of combining model fragments from an ARCIMBOLDO run requires their referral to a common origin and is complicated by the presence of correct and incorrect solutions as well as by their not being independent. The F-weighted mean phase difference has been used as a figure of merit. Clustering perfect, non-overlapping fragments dismembered from test structures in polar and nonpolar space groups shows that density modification before determining the relative origin shift enhances its discrimination. In the case of nonpolar space groups, clustering of ARCIMBOLDO solutions from secondary-structure models is feasible. The use of partially overlapping search fragments provides a more favourable circumstance and was assessed on a test case. Applying the devised strategy, a previously unknown structure was solved from clustered correct partial solutions.
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Affiliation(s)
- Claudia Millán
- Structural Biology, Instituto de Biologia Molecular de Barcelona, Carrer Baldiri Reixac 15, 3 A17, 08028 Barcelona, Spain
| | - Massimo Sammito
- Structural Biology, Instituto de Biologia Molecular de Barcelona, Carrer Baldiri Reixac 15, 3 A17, 08028 Barcelona, Spain
| | - Irene Garcia-Ferrer
- Structural Biology, Instituto de Biologia Molecular de Barcelona, Carrer Baldiri Reixac 15, 3 A17, 08028 Barcelona, Spain
| | - Theodoros Goulas
- Structural Biology, Instituto de Biologia Molecular de Barcelona, Carrer Baldiri Reixac 15, 3 A17, 08028 Barcelona, Spain
| | - George M Sheldrick
- Structural Chemistry, Institut für Anorganische Chemie, University of Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Isabel Usón
- Structural Biology, ICREA at IBMB-CSIC, Carrer Baldiri Reixac 13-15, 08028 Barcelona, Spain
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45
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Hudson DA, Thorpe C. Mia40 is a facile oxidant of unfolded reduced proteins but shows minimal isomerase activity. Arch Biochem Biophys 2015; 579:1-7. [PMID: 26014136 PMCID: PMC4500674 DOI: 10.1016/j.abb.2015.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 01/22/2023]
Abstract
Mia40 participates in oxidative protein folding within the mitochondrial intermembrane space (IMS) by mediating the transfer of reducing equivalents from client proteins to FAD-linked oxidoreductases of the Erv1 family (lfALR in mammals). Here we investigate the specificity of the human Mia40/lfALR system towards non-cognate unfolded protein substrates to assess whether the efficient introduction of disulfides requires a particular amino acid sequence context or the presence of an IMS targeting signal. Reduced pancreatic ribonuclease A (rRNase), avian lysozyme, and riboflavin binding protein are all competent substrates of the Mia40/lfALR system, although they lack those sequence features previously thought to direct disulfide bond formation in cognate IMS substrates. The oxidation of rRNase by Mia40 does not limit overall turnover of unfolded substrate by the Mia40/lfALR system. Mia40 is an ineffective protein disulfide isomerase when its ability to restore enzymatic activity from scrambled RNase is compared to that of protein disulfide isomerase. Mia40's ability to bind amphipathic peptides is evident by avid binding to the isolated B-chain during the insulin reductase assay. In aggregate these data suggest that the Mia40/lfALR system has a broad sequence specificity and that potential substrates may be protected from adventitious oxidation by kinetic sequestration within the mitochondrial IMS.
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Affiliation(s)
- Devin A Hudson
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States
| | - Colin Thorpe
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States.
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46
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Neal SE, Dabir DV, Tienson HL, Horn DM, Glaeser K, Ogozalek Loo RR, Barrientos A, Koehler CM. Mia40 Protein Serves as an Electron Sink in the Mia40-Erv1 Import Pathway. J Biol Chem 2015; 290:20804-20814. [PMID: 26085103 DOI: 10.1074/jbc.m115.669440] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Indexed: 11/06/2022] Open
Abstract
A redox-regulated import pathway consisting of Mia40 and Erv1 mediates the import of cysteine-rich proteins into the mitochondrial intermembrane space. Mia40 is the oxidoreductase that inserts two disulfide bonds into the substrate simultaneously. However, Mia40 has one redox-active cysteine pair, resulting in ambiguity about how Mia40 accepts numerous electrons during substrate oxidation. In this study, we have addressed the oxidation of Tim13 in vitro and in organello. Reductants such as glutathione and ascorbate inhibited both the oxidation of the substrate Tim13 in vitro and the import of Tim13 and Cmc1 into isolated mitochondria. In addition, a ternary complex consisting of Erv1, Mia40, and substrate, linked by disulfide bonds, was not detected in vitro. Instead, Mia40 accepted six electrons from substrates, and this fully reduced Mia40 was sensitive to protease, indicative of conformational changes in the structure. Mia40 in mitochondria from the erv1-101 mutant was also trapped in a completely reduced state, demonstrating that Mia40 can accept up to six electrons as substrates are imported. Therefore, these studies support that Mia40 functions as an electron sink to facilitate the insertion of two disulfide bonds into substrates.
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Affiliation(s)
- Sonya E Neal
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095
| | - Deepa V Dabir
- Department of Biology, Loyola Marymount University, Los Angeles, California 90045
| | - Heather L Tienson
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095
| | - Darryl M Horn
- Department of Neurology and Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Kathrin Glaeser
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095
| | - Rachel R Ogozalek Loo
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095
| | - Antoni Barrientos
- Department of Neurology and Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Carla M Koehler
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095.
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47
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Abstract
The content of mitochondrial proteome is maintained through two highly dynamic processes, the influx of newly synthesized proteins from the cytosol and the protein degradation. Mitochondrial proteins are targeted to the intermembrane space by the mitochondrial intermembrane space assembly pathway that couples their import and oxidative folding. The folding trap was proposed to be a driving mechanism for the mitochondrial accumulation of these proteins. Whether the reverse movement of unfolded proteins to the cytosol occurs across the intact outer membrane is unknown. We found that reduced, conformationally destabilized proteins are released from mitochondria in a size-limited manner. We identified the general import pore protein Tom40 as an escape gate. We propose that the mitochondrial proteome is not only regulated by the import and degradation of proteins but also by their retro-translocation to the external cytosolic location. Thus, protein release is a mechanism that contributes to the mitochondrial proteome surveillance.
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48
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Szarka A, Bánhegyi G. Oxidative folding: recent developments. Biomol Concepts 2015; 2:379-90. [PMID: 25962043 DOI: 10.1515/bmc.2011.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 07/21/2011] [Indexed: 01/29/2023] Open
Abstract
Disulfide bond formation in proteins is an effective tool of both structure stabilization and redox regulation. The prokaryotic periplasm and the endoplasmic reticulum of eukaryotes were long considered as the only compartments for enzyme mediated formation of stable disulfide bonds. Recently, the mitochondrial intermembrane space has emerged as the third protein-oxidizing compartment. The classic view on the mechanism of oxidative folding in the endoplasmic reticulum has also been reshaped by new observations. Moreover, besides the structure stabilizing function, reversible disulfide bridge formation in some proteins of the endoplasmic reticulum, seems to play a regulatory role. This review briefly summarizes the present knowledge of the redox systems supporting oxidative folding, emphasizing recent developments.
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49
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Mechanisms and physiological impact of the dual localization of mitochondrial intermembrane space proteins. Biochem Soc Trans 2015; 42:952-8. [PMID: 25109985 DOI: 10.1042/bst20140104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Eukaryotic cells developed diverse mechanisms to guide proteins to more than one destination within the cell. Recently, the proteome of the IMS (intermembrane space) of mitochondria of yeast cells was identified showing that approximately 20% of all soluble IMS proteins are dually localized to the IMS, as well as to other cellular compartments. Half of these dually localized proteins are important for oxidative stress defence and the other half are involved in energy homoeostasis. In the present review, we discuss the mechanisms leading to the dual localization of IMS proteins and the implications for mitochondrial function.
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50
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Barchiesi A, Wasilewski M, Chacinska A, Tell G, Vascotto C. Mitochondrial translocation of APE1 relies on the MIA pathway. Nucleic Acids Res 2015; 43:5451-64. [PMID: 25956655 PMCID: PMC4477663 DOI: 10.1093/nar/gkv433] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/23/2015] [Indexed: 01/08/2023] Open
Abstract
APE1 is a multifunctional protein with a fundamental role in repairing nuclear and mitochondrial DNA lesions caused by oxidative and alkylating agents. Unfortunately, comprehensions of the mechanisms regulating APE1 intracellular trafficking are still fragmentary and contrasting. Recent data demonstrate that APE1 interacts with the mitochondrial import and assembly protein Mia40 suggesting the involvement of a redox-assisted mechanism, dependent on the disulfide transfer system, to be responsible of APE1 trafficking into the mitochondria. The MIA pathway is an import machinery that uses a redox system for cysteine enriched proteins to drive them in this compartment. It is composed by two main proteins: Mia40 is the oxidoreductase that catalyzes the formation of the disulfide bonds in the substrate, while ALR reoxidizes Mia40 after the import. In this study, we demonstrated that: (i) APE1 and Mia40 interact through disulfide bond formation; and (ii) Mia40 expression levels directly affect APE1's mitochondrial translocation and, consequently, play a role in the maintenance of mitochondrial DNA integrity. In summary, our data strongly support the hypothesis of a redox-assisted mechanism, dependent on Mia40, in controlling APE1 translocation into the mitochondrial inner membrane space and thus highlight the role of this protein transport pathway in the maintenance of mitochondrial DNA stability and cell survival.
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Affiliation(s)
- Arianna Barchiesi
- Department of Medical and Biological Sciences, University of Udine, Udine 33100, Italy
| | - Michal Wasilewski
- International Institute of Molecular and Cell Biology, Warsaw, 02-109, Poland
| | - Agnieszka Chacinska
- International Institute of Molecular and Cell Biology, Warsaw, 02-109, Poland
| | - Gianluca Tell
- Department of Medical and Biological Sciences, University of Udine, Udine 33100, Italy
| | - Carlo Vascotto
- Department of Medical and Biological Sciences, University of Udine, Udine 33100, Italy
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