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Horten P, Song K, Garlich J, Hardt R, Colina-Tenorio L, Horvath SE, Schulte U, Fakler B, van der Laan M, Becker T, Stuart RA, Pfanner N, Rampelt H. Identification of MIMAS, a multifunctional mega-assembly integrating metabolic and respiratory biogenesis factors of mitochondria. Cell Rep 2024; 43:113772. [PMID: 38393949 PMCID: PMC11010658 DOI: 10.1016/j.celrep.2024.113772] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/03/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The mitochondrial inner membrane plays central roles in bioenergetics and metabolism and contains several established membrane protein complexes. Here, we report the identification of a mega-complex of the inner membrane, termed mitochondrial multifunctional assembly (MIMAS). Its large size of 3 MDa explains why MIMAS has escaped detection in the analysis of mitochondria so far. MIMAS combines proteins of diverse functions from respiratory chain assembly to metabolite transport, dehydrogenases, and lipid biosynthesis but not the large established supercomplexes of the respiratory chain, ATP synthase, or prohibitin scaffold. MIMAS integrity depends on the non-bilayer phospholipid phosphatidylethanolamine, in contrast to respiratory supercomplexes whose stability depends on cardiolipin. Our findings suggest that MIMAS forms a protein-lipid mega-assembly in the mitochondrial inner membrane that integrates respiratory biogenesis and metabolic processes in a multifunctional platform.
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Affiliation(s)
- Patrick Horten
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Kuo Song
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Joshua Garlich
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Robert Hardt
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, 53115 Bonn, Germany
| | - Lilia Colina-Tenorio
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Susanne E Horvath
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine, Saarland University, 66421 Homburg, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, 53115 Bonn, Germany
| | - Rosemary A Stuart
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| | - Heike Rampelt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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2
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Taskin AA, Moretti DN, Vögtle FN, Meisinger C. Isolation and Quality Control of Yeast Mitochondria. Methods Mol Biol 2023; 2615:41-55. [PMID: 36807783 DOI: 10.1007/978-1-0716-2922-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The isolation of organelles devoid of other cellular compartments is crucial for studying organellar proteomes and the localization of newly identified proteins, as well as for assessing specific organellar functions. Here, we describe a protocol for the isolation of crude and highly pure mitochondria from Saccharomyces cerevisiae and provide methods for testing the functional integrity of the isolated organelles.
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Affiliation(s)
- Asli Aras Taskin
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Daiana Nerina Moretti
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - F Nora Vögtle
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany. .,CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany. .,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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3
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Robinson DRL, Hock DH, Muellner-Wong L, Kugapreethan R, Reljic B, Surgenor EE, Rodrigues CHM, Caruana NJ, Stroud DA. Applying Sodium Carbonate Extraction Mass Spectrometry to Investigate Defects in the Mitochondrial Respiratory Chain. Front Cell Dev Biol 2022; 10:786268. [PMID: 35300415 PMCID: PMC8921082 DOI: 10.3389/fcell.2022.786268] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/03/2022] [Indexed: 12/03/2022] Open
Abstract
Mitochondria are complex organelles containing 13 proteins encoded by mitochondrial DNA and over 1,000 proteins encoded on nuclear DNA. Many mitochondrial proteins are associated with the inner or outer mitochondrial membranes, either peripherally or as integral membrane proteins, while others reside in either of the two soluble mitochondrial compartments, the mitochondrial matrix and the intermembrane space. The biogenesis of the five complexes of the oxidative phosphorylation system are exemplars of this complexity. These large multi-subunit complexes are comprised of more than 80 proteins with both membrane integral and peripheral associations and require soluble, membrane integral and peripherally associated assembly factor proteins for their biogenesis. Mutations causing human mitochondrial disease can lead to defective complex assembly due to the loss or altered function of the affected protein and subsequent destabilization of its interactors. Here we couple sodium carbonate extraction with quantitative mass spectrometry (SCE-MS) to track changes in the membrane association of the mitochondrial proteome across multiple human knockout cell lines. In addition to identifying the membrane association status of over 840 human mitochondrial proteins, we show how SCE-MS can be used to understand the impacts of defective complex assembly on protein solubility, giving insights into how specific subunits and sub-complexes become destabilized.
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Affiliation(s)
- David R L Robinson
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Daniella H Hock
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Linden Muellner-Wong
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,The Royal Children's Hospital, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Roopasingam Kugapreethan
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Boris Reljic
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Elliot E Surgenor
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.,The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Carlos H M Rodrigues
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Nikeisha J Caruana
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - David A Stroud
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,The Royal Children's Hospital, Murdoch Children's Research Institute, Parkville, VIC, Australia
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4
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Rampelt H, Wollweber F, Licheva M, de Boer R, Perschil I, Steidle L, Becker T, Bohnert M, van der Klei I, Kraft C, van der Laan M, Pfanner N. Dual role of Mic10 in mitochondrial cristae organization and ATP synthase-linked metabolic adaptation and respiratory growth. Cell Rep 2022; 38:110290. [PMID: 35081352 PMCID: PMC8810396 DOI: 10.1016/j.celrep.2021.110290] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/01/2021] [Accepted: 12/29/2021] [Indexed: 12/15/2022] Open
Abstract
Invaginations of the mitochondrial inner membrane, termed cristae, are hubs for oxidative phosphorylation. The mitochondrial contact site and cristae organizing system (MICOS) and the dimeric F1Fo-ATP synthase play important roles in controlling cristae architecture. A fraction of the MICOS core subunit Mic10 is found in association with the ATP synthase, yet it is unknown whether this interaction is of relevance for mitochondrial or cellular functions. Here, we established conditions to selectively study the role of Mic10 at the ATP synthase. Mic10 variants impaired in MICOS functions stimulate ATP synthase oligomerization like wild-type Mic10 and promote efficient inner membrane energization, adaptation to non-fermentable carbon sources, and respiratory growth. Mic10's functions in respiratory growth largely depend on Mic10ATPsynthase, not on Mic10MICOS. We conclude that Mic10 plays a dual role as core subunit of MICOS and as partner of the F1Fo-ATP synthase, serving distinct functions in cristae shaping and respiratory adaptation and growth. Dual role of Mic10 of mitochondrial contact site and cristae organizing system (MICOS) Mic10 binds to mitochondrial ATP synthase and stabilizes higher order assemblies Oligomerization of Mic10 is required for its function in MICOS, not at ATP synthase Mic10 binding to ATP synthase supports metabolic adaptation and respiratory growth
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Affiliation(s)
- Heike Rampelt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| | - Florian Wollweber
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine, Saarland University, 66421 Homburg, Germany
| | - Mariya Licheva
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Rinse de Boer
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700 Groningen, the Netherlands
| | - Inge Perschil
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Liesa Steidle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, 53115 Bonn, Germany
| | - Maria Bohnert
- Institute of Cell Dynamics and Imaging, Cells in Motion Interfaculty Centre (CiM), University of Münster, 48149 Münster, Germany
| | - Ida van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700 Groningen, the Netherlands
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Martin van der Laan
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine, Saarland University, 66421 Homburg, Germany.
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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5
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Walter C, Marada A, Suhm T, Ernsberger R, Muders V, Kücükköse C, Sánchez-Martín P, Hu Z, Aich A, Loroch S, Solari FA, Poveda-Huertes D, Schwierzok A, Pommerening H, Matic S, Brix J, Sickmann A, Kraft C, Dengjel J, Dennerlein S, Brummer T, Vögtle FN, Meisinger C. Global kinome profiling reveals DYRK1A as critical activator of the human mitochondrial import machinery. Nat Commun 2021; 12:4284. [PMID: 34257281 PMCID: PMC8277783 DOI: 10.1038/s41467-021-24426-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 06/15/2021] [Indexed: 11/21/2022] Open
Abstract
The translocase of the outer mitochondrial membrane TOM constitutes the organellar entry gate for nearly all precursor proteins synthesized on cytosolic ribosomes. Thus, TOM presents the ideal target to adjust the mitochondrial proteome upon changing cellular demands. Here, we identify that the import receptor TOM70 is targeted by the kinase DYRK1A and that this modification plays a critical role in the activation of the carrier import pathway. Phosphorylation of TOM70Ser91 by DYRK1A stimulates interaction of TOM70 with the core TOM translocase. This enables transfer of receptor-bound precursors to the translocation pore and initiates their import. Consequently, loss of TOM70Ser91 phosphorylation results in a strong decrease in import capacity of metabolite carriers. Inhibition of DYRK1A impairs mitochondrial structure and function and elicits a protective transcriptional response to maintain a functional import machinery. The DYRK1A-TOM70 axis will enable insights into disease mechanisms caused by dysfunctional DYRK1A, including autism spectrum disorder, microcephaly and Down syndrome.
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Affiliation(s)
- Corvin Walter
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Adinarayana Marada
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tamara Suhm
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ralf Ernsberger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Vera Muders
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Cansu Kücükköse
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Zehan Hu
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Abhishek Aich
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Stefan Loroch
- Leibniz Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | | | - Daniel Poveda-Huertes
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alexandra Schwierzok
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Henrike Pommerening
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stanka Matic
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jan Brix
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Albert Sickmann
- Leibniz Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Jörn Dengjel
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Sven Dennerlein
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Tilman Brummer
- Institute of Molecular Medicine, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- German Cancer Consortium DKTK Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - F-Nora Vögtle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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6
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Polymerase delta-interacting protein 38 (PDIP38) modulates the stability and activity of the mitochondrial AAA+ protease CLPXP. Commun Biol 2020; 3:646. [PMID: 33159171 PMCID: PMC7647994 DOI: 10.1038/s42003-020-01358-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 10/09/2020] [Indexed: 02/06/2023] Open
Abstract
Over a decade ago Polymerase δ interacting protein of 38 kDa (PDIP38) was proposed to play a role in DNA repair. Since this time, both the physiological function and subcellular location of PDIP38 has remained ambiguous and our present understanding of PDIP38 function has been hampered by a lack of detailed biochemical and structural studies. Here we show, that human PDIP38 is directed to the mitochondrion in a membrane potential dependent manner, where it resides in the matrix compartment, together with its partner protein CLPX. Our structural analysis revealed that PDIP38 is composed of two conserved domains separated by an α/β linker region. The N-terminal (YccV-like) domain of PDIP38 forms an SH3-like β-barrel, which interacts specifically with CLPX, via the adaptor docking loop within the N-terminal Zinc binding domain of CLPX. In contrast, the C-terminal (DUF525) domain forms an immunoglobin-like β-sandwich fold, which contains a highly conserved putative substrate binding pocket. Importantly, PDIP38 modulates the substrate specificity of CLPX and protects CLPX from LONM-mediated degradation, which stabilises the cellular levels of CLPX. Collectively, our findings shed new light on the mechanism and function of mitochondrial PDIP38, demonstrating that PDIP38 is a bona fide adaptor protein for the mitochondrial protease, CLPXP. Strack et al find that Polymerase δ interacting protein 38 (PDIP38) is targeted to the mitochondrial matrix where it colocalises with the mitochondrial AAA + protein CLPXP. PDIP38 modulates the specificity of CLPXP in vitro and alters the stability of CLPX in vitro and in cells. The PDIP38 structure leads the authors to speculate that PDIP38 is a CLPXP adaptor.
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7
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Rampelt H, Sucec I, Bersch B, Horten P, Perschil I, Martinou JC, van der Laan M, Wiedemann N, Schanda P, Pfanner N. The mitochondrial carrier pathway transports non-canonical substrates with an odd number of transmembrane segments. BMC Biol 2020; 18:2. [PMID: 31907035 PMCID: PMC6945462 DOI: 10.1186/s12915-019-0733-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 12/17/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The mitochondrial pyruvate carrier (MPC) plays a central role in energy metabolism by transporting pyruvate across the inner mitochondrial membrane. Its heterodimeric composition and homology to SWEET and semiSWEET transporters set the MPC apart from the canonical mitochondrial carrier family (named MCF or SLC25). The import of the canonical carriers is mediated by the carrier translocase of the inner membrane (TIM22) pathway and is dependent on their structure, which features an even number of transmembrane segments and both termini in the intermembrane space. The import pathway of MPC proteins has not been elucidated. The odd number of transmembrane segments and positioning of the N-terminus in the matrix argues against an import via the TIM22 carrier pathway but favors an import via the flexible presequence pathway. RESULTS Here, we systematically analyzed the import pathways of Mpc2 and Mpc3 and report that, contrary to an expected import via the flexible presequence pathway, yeast MPC proteins with an odd number of transmembrane segments and matrix-exposed N-terminus are imported by the carrier pathway, using the receptor Tom70, small TIM chaperones, and the TIM22 complex. The TIM9·10 complex chaperones MPC proteins through the mitochondrial intermembrane space using conserved hydrophobic motifs that are also required for the interaction with canonical carrier proteins. CONCLUSIONS The carrier pathway can import paired and non-paired transmembrane helices and translocate N-termini to either side of the mitochondrial inner membrane, revealing an unexpected versatility of the mitochondrial import pathway for non-cleavable inner membrane proteins.
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Affiliation(s)
- Heike Rampelt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
| | - Iva Sucec
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 38000, Grenoble, France
| | - Beate Bersch
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 38000, Grenoble, France
| | - Patrick Horten
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Inge Perschil
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany
| | | | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, 66421 Homburg, Germany
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
| | - Paul Schanda
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 38000, Grenoble, France
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
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8
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9
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Niemi NM, Wilson GM, Overmyer KA, Vögtle FN, Myketin L, Lohman DC, Schueler KL, Attie AD, Meisinger C, Coon JJ, Pagliarini DJ. Pptc7 is an essential phosphatase for promoting mammalian mitochondrial metabolism and biogenesis. Nat Commun 2019; 10:3197. [PMID: 31324765 PMCID: PMC6642090 DOI: 10.1038/s41467-019-11047-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 06/14/2019] [Indexed: 11/24/2022] Open
Abstract
Mitochondrial proteins are replete with phosphorylation, yet its functional relevance remains largely unclear. The presence of multiple resident mitochondrial phosphatases, however, suggests that protein dephosphorylation may be broadly important for calibrating mitochondrial activities. To explore this, we deleted the poorly characterized matrix phosphatase Pptc7 from mice using CRISPR-Cas9 technology. Strikingly, Pptc7−/− mice exhibit hypoketotic hypoglycemia, elevated acylcarnitines and serum lactate, and die soon after birth. Pptc7−/− tissues have markedly diminished mitochondrial size and protein content despite normal transcript levels, and aberrantly elevated phosphorylation on select mitochondrial proteins. Among these, we identify the protein translocase complex subunit Timm50 as a putative Pptc7 substrate whose phosphorylation reduces import activity. We further find that phosphorylation within or near the mitochondrial targeting sequences of multiple proteins could disrupt their import rates and matrix processing. Overall, our data define Pptc7 as a protein phosphatase essential for proper mitochondrial function and biogenesis during the extrauterine transition. The mitochondria houses several phosphatases, but their function is not well characterized. Here, the authors show that mitochondrial phosphatase Pptc7 is important during development for proper mitochondrial function and has a role regulating protein import with the translocase subunit Timm50.
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Affiliation(s)
- Natalie M Niemi
- Morgridge Institute for Research, Madison, WI, 53715, USA.,Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Gary M Wilson
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Katherine A Overmyer
- Morgridge Institute for Research, Madison, WI, 53715, USA.,Genome Center of Wisconsin, Madison, WI, 53706, USA
| | - F-Nora Vögtle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, 79104, Germany
| | - Lisa Myketin
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, 79104, Germany
| | | | - Kathryn L Schueler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Chris Meisinger
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg im Breisgau, 79104, Germany
| | - Joshua J Coon
- Morgridge Institute for Research, Madison, WI, 53715, USA.,Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Genome Center of Wisconsin, Madison, WI, 53706, USA.,Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - David J Pagliarini
- Morgridge Institute for Research, Madison, WI, 53715, USA. .,Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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10
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Weinhäupl K, Lindau C, Hessel A, Wang Y, Schütze C, Jores T, Melchionda L, Schönfisch B, Kalbacher H, Bersch B, Rapaport D, Brennich M, Lindorff-Larsen K, Wiedemann N, Schanda P. Structural Basis of Membrane Protein Chaperoning through the Mitochondrial Intermembrane Space. Cell 2018; 175:1365-1379.e25. [PMID: 30445040 PMCID: PMC6242696 DOI: 10.1016/j.cell.2018.10.039] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 08/16/2018] [Accepted: 10/15/2018] [Indexed: 12/04/2022]
Abstract
The exchange of metabolites between the mitochondrial matrix and the cytosol depends on β-barrel channels in the outer membrane and α-helical carrier proteins in the inner membrane. The essential translocase of the inner membrane (TIM) chaperones escort these proteins through the intermembrane space, but the structural and mechanistic details remain elusive. We have used an integrated structural biology approach to reveal the functional principle of TIM chaperones. Multiple clamp-like binding sites hold the mitochondrial membrane proteins in a translocation-competent elongated form, thus mimicking characteristics of co-translational membrane insertion. The bound preprotein undergoes conformational dynamics within the chaperone binding clefts, pointing to a multitude of dynamic local binding events. Mutations in these binding sites cause cell death or growth defects associated with impairment of carrier and β-barrel protein biogenesis. Our work reveals how a single mitochondrial "transfer-chaperone" system is able to guide α-helical and β-barrel membrane proteins in a "nascent chain-like" conformation through a ribosome-free compartment.
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Affiliation(s)
- Katharina Weinhäupl
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Caroline Lindau
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Audrey Hessel
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Yong Wang
- Structural Biology and NMR Laboratory, the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Conny Schütze
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Tobias Jores
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Laura Melchionda
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Birgit Schönfisch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Beate Bersch
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Martha Brennich
- European Molecular Biology Laboratory, 38042 Grenoble, France
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| | - Paul Schanda
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France.
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11
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Perrault syndrome type 3 caused by diverse molecular defects in CLPP. Sci Rep 2018; 8:12862. [PMID: 30150665 PMCID: PMC6110781 DOI: 10.1038/s41598-018-30311-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/25/2018] [Indexed: 02/02/2023] Open
Abstract
The maintenance of mitochondrial protein homeostasis (proteostasis) is crucial for correct cellular function. Recently, several mutations in the mitochondrial protease CLPP have been identified in patients with Perrault syndrome 3 (PRLTS3). These mutations can be arranged into two groups, those that cluster near the docking site (hydrophobic pocket, Hp) for the cognate unfoldase CLPX (i.e. T145P and C147S) and those that are adjacent to the active site of the peptidase (i.e. Y229D). Here we report the biochemical consequence of mutations in both regions. The Y229D mutant not only inhibited CLPP-peptidase activity, but unexpectedly also prevented CLPX-docking, thereby blocking the turnover of both peptide and protein substrates. In contrast, Hp mutations cause a range of biochemical defects in CLPP, from no observable change to CLPP activity for the C147S mutant, to dramatic disruption of most activities for the “gain-of-function” mutant T145P - including loss of oligomeric assembly and enhanced peptidase activity.
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12
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Shepherd DL, Hathaway QA, Nichols CE, Durr AJ, Pinti MV, Hughes KM, Kunovac A, Stine SM, Hollander JM. Mitochondrial proteome disruption in the diabetic heart through targeted epigenetic regulation at the mitochondrial heat shock protein 70 (mtHsp70) nuclear locus. J Mol Cell Cardiol 2018; 119:104-115. [PMID: 29733819 DOI: 10.1016/j.yjmcc.2018.04.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/26/2018] [Accepted: 04/28/2018] [Indexed: 01/17/2023]
Abstract
>99% of the mitochondrial proteome is nuclear-encoded. The mitochondrion relies on a coordinated multi-complex process for nuclear genome-encoded mitochondrial protein import. Mitochondrial heat shock protein 70 (mtHsp70) is a key component of this process and a central constituent of the protein import motor. Type 2 diabetes mellitus (T2DM) disrupts mitochondrial proteomic signature which is associated with decreased protein import efficiency. The goal of this study was to manipulate the mitochondrial protein import process through targeted restoration of mtHsp70, in an effort to restore proteomic signature and mitochondrial function in the T2DM heart. A novel line of cardiac-specific mtHsp70 transgenic mice on the db/db background were generated and cardiac mitochondrial subpopulations were isolated with proteomic evaluation and mitochondrial function assessed. MicroRNA and epigenetic regulation of the mtHsp70 gene during T2DM were also evaluated. MtHsp70 overexpression restored cardiac function and nuclear-encoded mitochondrial protein import, contributing to a beneficial impact on proteome signature and enhanced mitochondrial function during T2DM. Further, transcriptional repression at the mtHsp70 genomic locus through increased localization of H3K27me3 during T2DM insult was observed. Our results suggest that restoration of a key protein import constituent, mtHsp70, provides therapeutic benefit through attenuation of mitochondrial and contractile dysfunction in T2DM.
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Affiliation(s)
- Danielle L Shepherd
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Quincy A Hathaway
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Cody E Nichols
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Andrya J Durr
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Mark V Pinti
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Kristen M Hughes
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Amina Kunovac
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - Seth M Stine
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States
| | - John M Hollander
- Division of Exercise Physiology, Mitochondrial, Metabolism and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26505, United States.
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13
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Höhr AIC, Lindau C, Wirth C, Qiu J, Stroud DA, Kutik S, Guiard B, Hunte C, Becker T, Pfanner N, Wiedemann N. Membrane protein insertion through a mitochondrial β-barrel gate. Science 2018; 359:359/6373/eaah6834. [PMID: 29348211 DOI: 10.1126/science.aah6834] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 10/12/2017] [Accepted: 12/14/2017] [Indexed: 11/02/2022]
Abstract
The biogenesis of mitochondria, chloroplasts, and Gram-negative bacteria requires the insertion of β-barrel proteins into the outer membranes. Homologous Omp85 proteins are essential for membrane insertion of β-barrel precursors. It is unknown if precursors are threaded through the Omp85-channel interior and exit laterally or if they are translocated into the membrane at the Omp85-lipid interface. We have mapped the interaction of a precursor in transit with the mitochondrial Omp85-channel Sam50 in the native membrane environment. The precursor is translocated into the channel interior, interacts with an internal loop, and inserts into the lateral gate by β-signal exchange. Transport through the Omp85-channel interior followed by release through the lateral gate into the lipid phase may represent a basic mechanism for membrane insertion of β-barrel proteins.
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Affiliation(s)
- Alexandra I C Höhr
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.,Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Caroline Lindau
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.,Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Christophe Wirth
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Jian Qiu
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - David A Stroud
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Stephan Kutik
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Bernard Guiard
- Centre de Génétique Moléculaire, CNRS, 91190 Gif-sur-Yvette, France
| | - Carola Hunte
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
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14
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Dumit VI, Zerbes RM, Kaeser-Pebernard S, Rackiewicz M, Wall MT, Gretzmeier C, Küttner V, van der Laan M, Braun RJ, Dengjel J. Respiratory status determines the effect of emodin on cell viability. Oncotarget 2018; 8:37478-37490. [PMID: 28415582 PMCID: PMC5514923 DOI: 10.18632/oncotarget.16396] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 03/01/2017] [Indexed: 12/20/2022] Open
Abstract
The anthraquinone emodin has been shown to have antineoplastic properties and a wealth of unconnected effects have been linked to its use, most of which are likely secondary outcomes of the drug treatment. The primary activity of emodin on cells has remained unknown. In the present study we demonstrate dramatic and extensive effects of emodin on the redox state of cells and on mitochondrial homeostasis, irrespectively of the cell type and organism, ranging from the yeast Saccharomyces cerevisiae to human cell lines and primary cells. Emodin binds to redox-active enzymes and its effectiveness depends on the oxidative and respiratory status of cells. We show that cells with efficient respiratory metabolism are less susceptible to emodin, whereas cells under glycolytic metabolism are more vulnerable to the compound. Our findings indicate that emodin acts in a similar way as known uncouplers of the mitochondrial electron transport chain and causes oxidative stress that particularly disturbs cancer cells.
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Affiliation(s)
- Verónica I Dumit
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany.,Center for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany.,Core Facility Proteomics, ZBSA, University of Freiburg, Freiburg, Germany
| | - Ralf M Zerbes
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Michal Rackiewicz
- Center for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany.,Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Mona T Wall
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany.,Center for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Christine Gretzmeier
- Center for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Victoria Küttner
- Center for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Martin van der Laan
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Ralf J Braun
- Institute of Cell Biology, University of Bayreuth, Bayreuth, Germany
| | - Jörn Dengjel
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany.,Center for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,Department of Biology, University of Fribourg, Fribourg, Switzerland
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15
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Kravic B, Harbauer AB, Romanello V, Simeone L, Vögtle FN, Kaiser T, Straubinger M, Huraskin D, Böttcher M, Cerqua C, Martin ED, Poveda-Huertes D, Buttgereit A, Rabalski AJ, Heuss D, Rudolf R, Friedrich O, Litchfield D, Marber M, Salviati L, Mougiakakos D, Neuhuber W, Sandri M, Meisinger C, Hashemolhosseini S. In mammalian skeletal muscle, phosphorylation of TOMM22 by protein kinase CSNK2/CK2 controls mitophagy. Autophagy 2018; 14:311-335. [PMID: 29165030 DOI: 10.1080/15548627.2017.1403716] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In yeast, Tom22, the central component of the TOMM (translocase of outer mitochondrial membrane) receptor complex, is responsible for the recognition and translocation of synthesized mitochondrial precursor proteins, and its protein kinase CK2-dependent phosphorylation is mandatory for TOMM complex biogenesis and proper mitochondrial protein import. In mammals, the biological function of protein kinase CSNK2/CK2 remains vastly elusive and it is unknown whether CSNK2-dependent phosphorylation of TOMM protein subunits has a similar role as that in yeast. To address this issue, we used a skeletal muscle-specific Csnk2b/Ck2β-conditional knockout (cKO) mouse model. Phenotypically, these skeletal muscle Csnk2b cKO mice showed reduced muscle strength and abnormal metabolic activity of mainly oxidative muscle fibers, which point towards mitochondrial dysfunction. Enzymatically, active muscle lysates from skeletal muscle Csnk2b cKO mice phosphorylate murine TOMM22, the mammalian ortholog of yeast Tom22, to a lower extent than lysates prepared from controls. Mechanistically, CSNK2-mediated phosphorylation of TOMM22 changes its binding affinity for mitochondrial precursor proteins. However, in contrast to yeast, mitochondrial protein import seems not to be affected in vitro using mitochondria isolated from muscles of skeletal muscle Csnk2b cKO mice. PINK1, a mitochondrial health sensor that undergoes constitutive import under physiological conditions, accumulates within skeletal muscle Csnk2b cKO fibers and labels abnormal mitochondria for removal by mitophagy as demonstrated by the appearance of mitochondria-containing autophagosomes through electron microscopy. Mitophagy can be normalized by either introduction of a phosphomimetic TOMM22 mutant in cultured myotubes, or by in vivo electroporation of phosphomimetic Tomm22 into muscles of mice. Importantly, transfection of the phosphomimetic Tomm22 mutant in muscle cells with ablated Csnk2b restored their oxygen consumption rate comparable to wild-type levels. In sum, our data show that mammalian CSNK2-dependent phosphorylation of TOMM22 is a critical switch for mitophagy and reveal CSNK2-dependent physiological implications on metabolism, muscle integrity and behavior.
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Affiliation(s)
- Bojana Kravic
- a Institute of Biochemistry, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Angelika B Harbauer
- b Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Biology , University of Freiburg , Germany
| | - Vanina Romanello
- c Department of Biomedical Science , University of Padova , Padova , Italy
| | - Luca Simeone
- a Institute of Biochemistry, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - F-Nora Vögtle
- l Institute of Biochemistry and Molecular Biology, ZBMZ, BIOSS (Centre for Biological Signalling Studies), Faculty of Medicine , University of Freiburg , Germany
| | - Tobias Kaiser
- a Institute of Biochemistry, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Marion Straubinger
- a Institute of Biochemistry, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Danyil Huraskin
- a Institute of Biochemistry, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Martin Böttcher
- d Department of Internal Medicine, Hematology and Oncology, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Cristina Cerqua
- e Clinical Genetics Unit, Department of Woman and Child Health , University of Padova, IRP Città della Speranza , Padova , Italy
| | - Eva Denise Martin
- f King's College London BHF Centre of Research Excellence, The Rayne Institute , St Thomas' Hospital , London , United Kingdom
| | - Daniel Poveda-Huertes
- b Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Biology , University of Freiburg , Germany
| | - Andreas Buttgereit
- g Institute of Medical Biotechnology , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | | | - Dieter Heuss
- i Department of Neurology , University Hospital of Erlangen, Medical Faculty, Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Rüdiger Rudolf
- j University of Applied Sciences Mannheim , Mannheim , Germany
| | - Oliver Friedrich
- g Institute of Medical Biotechnology , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | | | - Michael Marber
- f King's College London BHF Centre of Research Excellence, The Rayne Institute , St Thomas' Hospital , London , United Kingdom
| | - Leonardo Salviati
- e Clinical Genetics Unit, Department of Woman and Child Health , University of Padova, IRP Città della Speranza , Padova , Italy
| | - Dimitrios Mougiakakos
- d Department of Internal Medicine, Hematology and Oncology, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Winfried Neuhuber
- k Institute of Anatomy, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
| | - Marco Sandri
- c Department of Biomedical Science , University of Padova , Padova , Italy
| | - Chris Meisinger
- l Institute of Biochemistry and Molecular Biology, ZBMZ, BIOSS (Centre for Biological Signalling Studies), Faculty of Medicine , University of Freiburg , Germany
| | - Said Hashemolhosseini
- a Institute of Biochemistry, Medical Faculty , Friedrich-Alexander-University of Erlangen-Nürnberg , Erlangen , Germany
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16
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A Farnesylated Coxiella burnetii Effector Forms a Multimeric Complex at the Mitochondrial Outer Membrane during Infection. Infect Immun 2017; 85:IAI.01046-16. [PMID: 28242621 DOI: 10.1128/iai.01046-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/17/2017] [Indexed: 01/16/2023] Open
Abstract
Coxiella burnetii, the causative agent of Q fever, establishes a unique lysosome-derived intracellular niche termed the Coxiella-containing vacuole (CCV). The Dot/Icm-type IVB secretion system is essential for the biogenesis of the CCV and the intracellular replication of Coxiella Effector proteins, translocated into the host cell through this apparatus, act to modulate host trafficking and signaling processes to facilitate CCV development. Here we investigated the role of CBU0077, a conserved Coxiella effector that had previously been observed to localize to lysosomal membranes. CBU0077 was dispensable for the intracellular replication of Coxiella in HeLa and THP-1 cells and did not appear to participate in CCV biogenesis. Intriguingly, native and epitope-tagged CBU0077 produced by Coxiella displayed specific punctate localization at host cell mitochondria. As such, we designated CBU0077 MceA (mitochondrial Coxiellaeffector protein A). Analysis of ectopically expressed MceA truncations revealed that the capacity to traffic to mitochondria is encoded within the first 84 amino acids of this protein. MceA is farnesylated by the host cell; however, this does not impact mitochondrial localization. Examination of mitochondria isolated from infected cells revealed that MceA is specifically integrated into the mitochondrial outer membrane and forms a complex of approximately 120 kDa. Engineering Coxiella to express either MceA tagged with 3×FLAG or MceA tagged with 2×hemagglutinin allowed us to perform immunoprecipitation experiments that showed that MceA forms a homo-oligomeric species at the mitochondrial outer membrane during infection. This research reveals that mitochondria are a bona fide target of Coxiella effectors and MceA is a complex-forming effector at the mitochondrial outer membrane during Coxiella infection.
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17
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Ruan L, Zhou C, Jin E, Kucharavy A, Zhang Y, Wen Z, Florens L, Li R. Cytosolic proteostasis through importing of misfolded proteins into mitochondria. Nature 2017; 543:443-446. [PMID: 28241148 PMCID: PMC5793917 DOI: 10.1038/nature21695] [Citation(s) in RCA: 315] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 02/09/2017] [Indexed: 12/31/2022]
Abstract
Loss of proteostasis underlies aging and neurodegeneration characterized by the accumulation of protein aggregates and mitochondrial dysfunction1–5. Although many neurodegenerative-disease proteins can be found in mitochondria4,6, it remains unclear how these disease manifestations may be related. In yeast, protein aggregates formed under stress or during aging are preferentially retained by the mother cell in part through tethering to mitochondria, while the disaggregase Hsp104 helps dissociate aggregates to enable refolding or degradation of misfolded proteins7–10. Here we show that in yeast cytosolic proteins prone to aggregation are imported into mitochondria for degradation. Protein aggregates formed under heat shock (HS) contain both cytosolic and mitochondrial proteins and interact with mitochondrial import complex. Many aggregation-prone proteins enter mitochondrial intermembrane space and matrix after HS, while some do so even without stress. Timely dissolution of cytosolic aggregates requires mitochondrial import machinery and proteases. Blocking mitochondrial import but not the proteasome activity causes a marked delay in the degradation of aggregated proteins. Defects in cytosolic Hsp70s leads to enhanced entry of misfolded proteins into mitochondria and elevated mitochondrial stress. We term this mitochondria-mediated proteostasis mechanism MAGIC (mitochondria as guardian in cytosol) and provide evidence that it may exist in human cells.
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Affiliation(s)
- Linhao Ruan
- Center for Cell Dynamics, Department of Cell Biology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, USA.,Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Chuankai Zhou
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, Missouri 64110, USA
| | - Erli Jin
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Andrei Kucharavy
- Center for Cell Dynamics, Department of Cell Biology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, USA.,Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Ying Zhang
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, Missouri 64110, USA
| | - Zhihui Wen
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, Missouri 64110, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, Missouri 64110, USA
| | - Rong Li
- Center for Cell Dynamics, Department of Cell Biology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, USA.,Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
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18
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LON is the master protease that protects against protein aggregation in human mitochondria through direct degradation of misfolded proteins. Sci Rep 2015; 5:17397. [PMID: 26627475 PMCID: PMC4667172 DOI: 10.1038/srep17397] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 10/19/2015] [Indexed: 01/08/2023] Open
Abstract
Maintenance of mitochondrial protein homeostasis is critical for proper cellular function. Under normal conditions resident molecular chaperones and proteases maintain protein homeostasis within the organelle. Under conditions of stress however, misfolded proteins accumulate leading to the activation of the mitochondrial unfolded protein response (UPRmt). While molecular chaperone assisted refolding of proteins in mammalian mitochondria has been well documented, the contribution of AAA+ proteases to the maintenance of protein homeostasis in this organelle remains unclear. To address this gap in knowledge we examined the contribution of human mitochondrial matrix proteases, LONM and CLPXP, to the turnover of OTC-∆, a folding incompetent mutant of ornithine transcarbamylase, known to activate UPRmt. Contrary to a model whereby CLPXP is believed to degrade misfolded proteins, we found that LONM, and not CLPXP is responsible for the turnover of OTC-∆ in human mitochondria. To analyse the conformational state of proteins that are recognised by LONM, we examined the turnover of unfolded and aggregated forms of malate dehydrogenase (MDH) and OTC. This analysis revealed that LONM specifically recognises and degrades unfolded, but not aggregated proteins. Since LONM is not upregulated by UPRmt, this pathway may preferentially act to promote chaperone mediated refolding of proteins.
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19
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Holloway G, Johnson RI, Kang Y, Dang VT, Stojanovski D, Coulson BS. Rotavirus NSP6 localizes to mitochondria via a predicted N-terminal α-helix. J Gen Virol 2015; 96:3519-3524. [DOI: 10.1099/jgv.0.000294] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Specific roles have been ascribed to each of the 12 known rotavirus proteins apart from the non-structural protein 6 (NSP6). However, NSP6 may be present at sites of viral replication within the cytoplasm. Here we report that NSP6 from diverse species of rotavirus A localizes to mitochondria via conserved sequences in a predicted N-terminal α-helix. This suggests that NSP6 may affect mitochondrial functions during rotavirus infection.
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Affiliation(s)
- Gavan Holloway
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Rebecca I. Johnson
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Yilin Kang
- Department of Biochemistry and Molecular Biology, The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Vi T. Dang
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Molecular Biology, The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Barbara S. Coulson
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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20
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Schuler MH, Di Bartolomeo F, Böttinger L, Horvath SE, Wenz LS, Daum G, Becker T. Phosphatidylcholine affects the role of the sorting and assembly machinery in the biogenesis of mitochondrial β-barrel proteins. J Biol Chem 2015; 290:26523-32. [PMID: 26385920 DOI: 10.1074/jbc.m115.687921] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Indexed: 11/06/2022] Open
Abstract
Two protein translocases drive the import of β-barrel precursor proteins into the mitochondrial outer membrane: The translocase of the outer membrane (TOM complex) promotes transport of the precursor to the intermembrane space, whereas the sorting and assembly machinery (SAM complex) mediates subsequent folding of the β-barrel and its integration into the target membrane. The non-bilayer-forming phospholipids phosphatidylethanolamine (PE) and cardiolipin (CL) are required for the biogenesis of β-barrel proteins. Whether bilayer-forming phospholipids such as phosphatidylcholine (PC), the most abundant phospholipid of the mitochondrial outer membrane, play a role in the import of β-barrel precursors is unclear. In this study, we show that PC is required for stability and function of the SAM complex during the biogenesis of β-barrel proteins. PC further promotes the SAM-dependent assembly of the TOM complex, indicating a general role of PC for the function of the SAM complex. In contrast to PE-deficient mitochondria precursor accumulation at the TOM complex is not affected by depletion of PC. We conclude that PC and PE affect the function of distinct protein translocases in mitochondrial β-barrel biogenesis.
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Affiliation(s)
- Max-Hinderk Schuler
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | | | - Lena Böttinger
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Susanne E Horvath
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Lena-Sophie Wenz
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Günther Daum
- Institute for Biochemistry, Graz University of Technology, NaWi Graz, A-8010 Graz, Austria,
| | - Thomas Becker
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany, BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
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21
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A presequence-binding groove in Tom70 supports import of Mdl1 into mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1850-9. [PMID: 25958336 DOI: 10.1016/j.bbamcr.2015.04.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/23/2015] [Accepted: 04/30/2015] [Indexed: 11/21/2022]
Abstract
The translocase of the outer mitochondrial membrane (TOM complex) is the general entry gate into mitochondria for almost all imported proteins. A variety of specific receptors allow the TOM complex to recognize targeting signals of various precursor proteins that are transported along different import pathways. Aside from the well-characterized presequence receptors Tom20 and Tom22 a third TOM receptor, Tom70, binds proteins of the carrier family containing multiple transmembrane segments. Here we demonstrate that Tom70 directly binds to presequence peptides using a dedicated groove. A single point mutation in the cavity of this pocket (M551R) reduces the presequence binding affinity of Tom70 ten-fold and selectively impairs import of the presequence-containing precursor Mdl1 but not the ADP/ATP carrier (AAC). Hence Tom70 contributes to the presequence import pathway by recognition of the targeting signal of the Mdl1 precursor.
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22
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Aiyar RS, Bohnert M, Duvezin-Caubet S, Voisset C, Gagneur J, Fritsch ES, Couplan E, von der Malsburg K, Funaya C, Soubigou F, Courtin F, Suresh S, Kucharczyk R, Evrard J, Antony C, St Onge RP, Blondel M, di Rago JP, van der Laan M, Steinmetz LM. Mitochondrial protein sorting as a therapeutic target for ATP synthase disorders. Nat Commun 2014; 5:5585. [PMID: 25519239 PMCID: PMC4284804 DOI: 10.1038/ncomms6585] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 10/16/2014] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial diseases are systemic, prevalent and often fatal; yet treatments remain scarce. Identifying molecular intervention points that can be therapeutically targeted remains a major challenge, which we confronted via a screening assay we developed. Using yeast models of mitochondrial ATP synthase disorders, we screened a drug repurposing library, and applied genomic and biochemical techniques to identify pathways of interest. Here we demonstrate that modulating the sorting of nuclear-encoded proteins into mitochondria, mediated by the TIM23 complex, proves therapeutic in both yeast and patient-derived cells exhibiting ATP synthase deficiency. Targeting TIM23-dependent protein sorting improves an array of phenotypes associated with ATP synthase disorders, including biogenesis and activity of the oxidative phosphorylation machinery. Our study establishes mitochondrial protein sorting as an intervention point for ATP synthase disorders, and because of the central role of this pathway in mitochondrial biogenesis, it holds broad value for the treatment of mitochondrial diseases.
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Affiliation(s)
- Raeka S Aiyar
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Maria Bohnert
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
| | - Stéphane Duvezin-Caubet
- 1] Université Bordeaux, IBGC, UMR 5095, F-33000 Bordeaux, France [2] CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France
| | - Cécile Voisset
- Institut National de la Santé et de la Recherche Médicale UMR1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Julien Gagneur
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Emilie S Fritsch
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Elodie Couplan
- Institut National de la Santé et de la Recherche Médicale UMR1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Karina von der Malsburg
- 1] Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany [2] BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany
| | - Charlotta Funaya
- European Molecular Biology Laboratory (EMBL), Electron Microscopy Core Facility, 69117 Heidelberg, Germany
| | - Flavie Soubigou
- Institut National de la Santé et de la Recherche Médicale UMR1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Florence Courtin
- 1] Université Bordeaux, IBGC, UMR 5095, F-33000 Bordeaux, France [2] CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France
| | - Sundari Suresh
- Stanford Genome Technology Center, Stanford University, Palo Alto, California 94304, USA
| | - Roza Kucharczyk
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Justine Evrard
- Institut National de la Santé et de la Recherche Médicale UMR1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Claude Antony
- European Molecular Biology Laboratory (EMBL), Electron Microscopy Core Facility, 69117 Heidelberg, Germany
| | - Robert P St Onge
- Stanford Genome Technology Center, Stanford University, Palo Alto, California 94304, USA
| | - Marc Blondel
- Institut National de la Santé et de la Recherche Médicale UMR1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Jean-Paul di Rago
- 1] Université Bordeaux, IBGC, UMR 5095, F-33000 Bordeaux, France [2] CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France
| | - Martin van der Laan
- 1] Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany [2] BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany
| | - Lars M Steinmetz
- 1] European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany [2] Stanford Genome Technology Center, Stanford University, Palo Alto, California 94304, USA [3] Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
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23
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Lesnik C, Cohen Y, Atir-Lande A, Schuldiner M, Arava Y. OM14 is a mitochondrial receptor for cytosolic ribosomes that supports co-translational import into mitochondria. Nat Commun 2014; 5:5711. [PMID: 25487825 PMCID: PMC4268710 DOI: 10.1038/ncomms6711] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 10/30/2014] [Indexed: 11/13/2022] Open
Abstract
It is well established that import of proteins into mitochondria can occur after their complete synthesis by cytosolic ribosomes. Recently, an additional model was revived, proposing that some proteins are imported co-translationally. This model entails association of ribosomes with the mitochondrial outer membrane, shown to be mediated through the ribosome-associated chaperone nascent chain-associated complex (NAC). However, the mitochondrial receptor of this complex is unknown. Here, we identify the Saccharomyces cerevisiae outer membrane protein OM14 as a receptor for NAC. OM14Δ mitochondria have significantly lower amounts of associated NAC and ribosomes, and ribosomes from NAC[Δ] cells have reduced levels of associated OM14. Importantly, mitochondrial import assays reveal a significant decrease in import efficiency into OM14Δ mitochondria, and OM14-dependent import necessitates NAC. Our results identify OM14 as the first mitochondrial receptor for ribosome-associated NAC and reveal its importance for import. These results provide a strong support for an additional, co-translational mode of import into mitochondria. Mitochondrial proteins can be imported post-translationally; however, a role for co-translational import has recently provoked renewed interest. Lesnik et al. identify OM14 as a mitochondrial ribosome receptor required for efficient co-translational import of mitochondrial proteins.
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Affiliation(s)
- Chen Lesnik
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yifat Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Avigail Atir-Lande
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoav Arava
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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24
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Harbauer AB, Opalińska M, Gerbeth C, Herman JS, Rao S, Schönfisch B, Guiard B, Schmidt O, Pfanner N, Meisinger C. Mitochondria. Cell cycle-dependent regulation of mitochondrial preprotein translocase. Science 2014; 346:1109-13. [PMID: 25378463 DOI: 10.1126/science.1261253] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondria play central roles in cellular energy conversion, metabolism, and apoptosis. Mitochondria import more than 1000 different proteins from the cytosol. It is unknown if the mitochondrial protein import machinery is connected to the cell division cycle. We found that the cyclin-dependent kinase Cdk1 stimulated assembly of the main mitochondrial entry gate, the translocase of the outer membrane (TOM), in mitosis. The molecular mechanism involved phosphorylation of the cytosolic precursor of Tom6 by cyclin Clb3-activated Cdk1, leading to enhanced import of Tom6 into mitochondria. Tom6 phosphorylation promoted assembly of the protein import channel Tom40 and import of fusion proteins, thus stimulating the respiratory activity of mitochondria in mitosis. Tom6 phosphorylation provides a direct means for regulating mitochondrial biogenesis and activity in a cell cycle-specific manner.
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Affiliation(s)
- Angelika B Harbauer
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. Trinationales Graduiertenkolleg 1478, Universität Freiburg, 79104 Freiburg, Germany. Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany. BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany
| | - Magdalena Opalińska
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
| | - Carolin Gerbeth
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. Trinationales Graduiertenkolleg 1478, Universität Freiburg, 79104 Freiburg, Germany. Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany
| | - Josip S Herman
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
| | - Sanjana Rao
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany. Spemann Graduate School of Biology and Medicine, Universität Freiburg, 79104 Freiburg, Germany
| | - Birgit Schönfisch
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
| | - Bernard Guiard
- Centre de Génétique Moléculaire, CNRS, 91190 Gif-sur-Yvette, France
| | - Oliver Schmidt
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany
| | - Nikolaus Pfanner
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany.
| | - Chris Meisinger
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany.
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25
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Cartron PF, Petit E, Bellot G, Oliver L, Vallette FM. Metaxins 1 and 2, two proteins of the mitochondrial protein sorting and assembly machinery, are essential for Bak activation during TNF alpha triggered apoptosis. Cell Signal 2014; 26:1928-34. [DOI: 10.1016/j.cellsig.2014.04.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 04/27/2014] [Indexed: 10/25/2022]
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26
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Lim S, Smith K, Stroud D, Compton A, Tucker E, Dasvarma A, Gandolfo L, Marum J, McKenzie M, Peters H, Mowat D, Procopis P, Wilcken B, Christodoulou J, Brown G, Ryan M, Bahlo M, Thorburn D. A founder mutation in PET100 causes isolated complex IV deficiency in Lebanese individuals with Leigh syndrome. Am J Hum Genet 2014; 94:209-22. [PMID: 24462369 DOI: 10.1016/j.ajhg.2013.12.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 12/18/2013] [Indexed: 12/30/2022] Open
Abstract
Leigh syndrome (LS) is a severe neurodegenerative disorder with characteristic bilateral lesions, typically in the brainstem and basal ganglia. It usually presents in infancy and is genetically heterogeneous, but most individuals with mitochondrial complex IV (or cytochrome c oxidase) deficiency have mutations in the biogenesis factor SURF1. We studied eight complex IV-deficient LS individuals from six families of Lebanese origin. They differed from individuals with SURF1 mutations in having seizures as a prominent feature. Complementation analysis suggested they had mutation(s) in the same gene but targeted massively parallel sequencing (MPS) of 1,034 genes encoding known mitochondrial proteins failed to identify a likely candidate. Linkage and haplotype analyses mapped the location of the gene to chromosome 19 and targeted MPS of the linkage region identified a homozygous c.3G>C (p.Met1?) mutation in C19orf79. Abolishing the initiation codon could potentially still allow initiation at a downstream methionine residue but we showed that this would not result in a functional protein. We confirmed that mutation of this gene was causative by lentiviral-mediated phenotypic correction. C19orf79 was recently renamed PET100 and predicted to encode a complex IV biogenesis factor. We showed that it is located in the mitochondrial inner membrane and forms a ∼300 kDa subcomplex with complex IV subunits. Previous proteomic analyses of mitochondria had overlooked PET100 because its small size was below the cutoff for annotating bona fide proteins. The mutation was estimated to have arisen at least 520 years ago, explaining how the families could have different religions and different geographic origins within Lebanon.
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27
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Bezawork-Geleta A, Saiyed T, Dougan DA, Truscott KN. Mitochondrial matrix proteostasis is linked to hereditary paraganglioma: LON-mediated turnover of the human flavinylation factor SDH5 is regulated by its interaction with SDHA. FASEB J 2014; 28:1794-804. [PMID: 24414418 DOI: 10.1096/fj.13-242420] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mutations in succinate dehydrogenase (SDH) subunits and assembly factors cause a range of clinical conditions. One such condition, hereditary paraganglioma 2 (PGL2), is caused by a G78R mutation in the assembly factor SDH5. Although SDH5(G78R) is deficient in its ability to promote SDHA flavinylation, it has remained unclear whether impairment to its import, structure, or stability contributes to its loss of function. Using import-chase analysis in human mitochondria isolated from HeLa cells, we found that the import and maturation of human SDH5(G78R) was normal, while its stability was reduced significantly, with ~25% of the protein remaining after 180 min compared to ~85% for the wild-type protein. Notably, the metabolic stability of SDH5(G78R) was restored to wild-type levels by depleting mitochondrial LON (LONM). Degradation of SDH5(G78R) by LONM was confirmed in vitro; however, in contrast to the in organello analysis, wild-type SDH5 was also rapidly degraded by LONM. SDH5 instability was confirmed in SDHA-depleted mitochondria. Blue native PAGE showed that imported SDH5(G78R) formed a transient complex with SDHA; however, this complex was stabilized in LONM depleted mitochondria. These data demonstrate that SDH5 is protected from LONM-mediated degradation in mitochondria by its stable interaction with SDHA, a state that is dysregulated in PGL2.
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Affiliation(s)
- Ayenachew Bezawork-Geleta
- 2Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Australia. K.N.T.,
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28
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Qiu J, Wenz LS, Zerbes RM, Oeljeklaus S, Bohnert M, Stroud DA, Wirth C, Ellenrieder L, Thornton N, Kutik S, Wiese S, Schulze-Specking A, Zufall N, Chacinska A, Guiard B, Hunte C, Warscheid B, van der Laan M, Pfanner N, Wiedemann N, Becker T. Coupling of mitochondrial import and export translocases by receptor-mediated supercomplex formation. Cell 2013; 154:596-608. [PMID: 23911324 DOI: 10.1016/j.cell.2013.06.033] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/13/2013] [Accepted: 06/19/2013] [Indexed: 11/17/2022]
Abstract
The mitochondrial outer membrane harbors two protein translocases that are essential for cell viability: the translocase of the outer mitochondrial membrane (TOM) and the sorting and assembly machinery (SAM). The precursors of β-barrel proteins use both translocases-TOM for import to the intermembrane space and SAM for export into the outer membrane. It is unknown if the translocases cooperate and where the β-barrel of newly imported proteins is formed. We established a position-specific assay for monitoring β-barrel formation in vivo and in organello and demonstrated that the β-barrel was formed and membrane inserted while the precursor was bound to SAM. β-barrel formation was inhibited by SAM mutants and, unexpectedly, by mutants of the central import receptor, Tom22. We show that the cytosolic domain of Tom22 links TOM and SAM into a supercomplex, facilitating precursor transfer on the intermembrane space side. Our study reveals receptor-mediated coupling of import and export translocases as a means of precursor channeling.
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Affiliation(s)
- Jian Qiu
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
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29
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Flinner N, Ellenrieder L, Stiller SB, Becker T, Schleiff E, Mirus O. Mdm10 is an ancient eukaryotic porin co-occurring with the ERMES complex. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3314-3325. [PMID: 24135058 DOI: 10.1016/j.bbamcr.2013.10.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 09/20/2013] [Accepted: 10/07/2013] [Indexed: 12/17/2022]
Abstract
Mitochondrial β-barrel proteins fulfill central functions in the outer membrane like metabolite exchange catalyzed by the voltage-dependent anion channel (VDAC) and protein biogenesis by the central components of the preprotein translocase of the outer membrane (Tom40) or of the sorting and assembly machinery (Sam50). The mitochondrial division and morphology protein Mdm10 is another essential outer membrane protein with proposed β-barrel fold, which has so far only been found in Fungi. Mdm10 is part of the endoplasmic reticulum mitochondria encounter structure (ERMES), which tethers the ER to mitochondria and associates with the SAM complex. In here, we provide evidence that Mdm10 phylogenetically belongs to the VDAC/Tom40 superfamily. Contrary to Tom40 and VDAC, Mdm10 exposes long loops towards both sides of the membrane. Analyses of single loop deletion mutants of Mdm10 in the yeast Saccharomyces cerevisiae reveal that the loops are dispensable for Mdm10 function. Sequences similar to fungal Mdm10 can be found in species from Excavates to Fungi, but neither in Metazoa nor in plants. Strikingly, the presence of Mdm10 coincides with the appearance of the other ERMES components. Mdm10's presence in both unikonts and bikonts indicates an introduction at an early time point in eukaryotic evolution.
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Affiliation(s)
- Nadine Flinner
- JWGU Frankfurt am Main, Cluster of Excellence Macromolecular Complexes, Centre of Membrane Proteomics, Department of Biosciences, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Lars Ellenrieder
- Institut für Biochemie und Molekularbiologie, Universität Freiburg, D-79104 Freiburg, Germany; Fakultät für Biologie, Universität Freiburg, D-79104 Freiburg, Germany
| | - Sebastian B Stiller
- Institut für Biochemie und Molekularbiologie, Universität Freiburg, D-79104 Freiburg, Germany; Fakultät für Biologie, Universität Freiburg, D-79104 Freiburg, Germany
| | - Thomas Becker
- Institut für Biochemie und Molekularbiologie, Universität Freiburg, D-79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Universität Freiburg, D-79104 Freiburg, Germany
| | - Enrico Schleiff
- JWGU Frankfurt am Main, Cluster of Excellence Macromolecular Complexes, Centre of Membrane Proteomics, Department of Biosciences, Max-von-Laue Str. 9, 60438 Frankfurt, Germany.
| | - Oliver Mirus
- JWGU Frankfurt am Main, Cluster of Excellence Macromolecular Complexes, Centre of Membrane Proteomics, Department of Biosciences, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
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30
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Gerbeth C, Schmidt O, Rao S, Harbauer AB, Mikropoulou D, Opalińska M, Guiard B, Pfanner N, Meisinger C. Glucose-induced regulation of protein import receptor Tom22 by cytosolic and mitochondria-bound kinases. Cell Metab 2013; 18:578-87. [PMID: 24093680 DOI: 10.1016/j.cmet.2013.09.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/29/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022]
Abstract
Most mitochondrial proteins are imported by the translocase of the outer mitochondrial membrane (TOM). Tom22 functions as central receptor and transfers preproteins to the import pore. Casein kinase 2 (CK2) constitutively phosphorylates the cytosolic precursor of Tom22 at Ser44 and Ser46 and, thus, promotes its import. It is unknown whether Tom22 is regulated under different metabolic conditions. We report that CK1, which is involved in glucose-induced signal transduction, is bound to mitochondria. CK1 phosphorylates Tom22 at Thr57 and stimulates the assembly of Tom22 and Tom20. In contrast, protein kinase A (PKA), which is also activated by the addition of glucose, phosphorylates the precursor of Tom22 at Thr76 and impairs its import. Thus, PKA functions in an opposite manner to CK1 and CK2. Our results reveal that three kinases regulate the import and assembly of Tom22, demonstrating that the central receptor is a major target for the posttranslational regulation of mitochondrial protein import.
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Affiliation(s)
- Carolin Gerbeth
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany; Trinationales Graduiertenkolleg 1478, Universität Freiburg, 79104 Freiburg, Germany; Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany
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31
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The Dependence Receptor TrkC Triggers Mitochondria-Dependent Apoptosis upon Cobra-1 Recruitment. Mol Cell 2013; 51:632-46. [DOI: 10.1016/j.molcel.2013.08.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 04/28/2013] [Accepted: 08/09/2013] [Indexed: 01/24/2023]
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32
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Böttinger L, Guiard B, Oeljeklaus S, Kulawiak B, Zufall N, Wiedemann N, Warscheid B, van der Laan M, Becker T. A complex of Cox4 and mitochondrial Hsp70 plays an important role in the assembly of the cytochrome c oxidase. Mol Biol Cell 2013; 24:2609-19. [PMID: 23864706 PMCID: PMC3756914 DOI: 10.1091/mbc.e13-02-0106] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The biogenesis of Cox4 is unknown. Cox4, mtHsp70, and Mge1 form a complex that promotes the assembly of cytochrome c oxidase. In the absence of the mature cytochrome c oxidase, Cox4 arrests at the chaperone complex. This complex delivers Cox4 into the assembly line of complex IV when needed. The formation of the mature cytochrome c oxidase (complex IV) involves the association of nuclear- and mitochondria-encoded subunits. The assembly of nuclear-encoded subunits like cytochrome c oxidase subunit 4 (Cox4) into the mature complex is poorly understood. Cox4 is crucial for the stability of complex IV. To find specific biogenesis factors, we analyze interaction partners of Cox4 by affinity purification and mass spectroscopy. Surprisingly, we identify a complex of Cox4, the mitochondrial Hsp70 (mtHsp70), and its nucleotide-exchange factor mitochondrial GrpE (Mge1). We generate a yeast mutant of mtHsp70 specifically impaired in the formation of this novel mtHsp70-Mge1-Cox4 complex. Strikingly, the assembly of Cox4 is strongly decreased in these mutant mitochondria. Because Cox4 is a key factor for the biogenesis of complex IV, we conclude that the mtHsp70-Mge1-Cox4 complex plays an important role in the formation of cytochrome c oxidase. Cox4 arrests at this chaperone complex in the absence of mature complex IV. Thus the mtHsp70-Cox4 complex likely serves as a novel delivery system to channel Cox4 into the assembly line when needed.
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Affiliation(s)
- Lena Böttinger
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
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33
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Becker T, Horvath SE, Böttinger L, Gebert N, Daum G, Pfanner N. Role of phosphatidylethanolamine in the biogenesis of mitochondrial outer membrane proteins. J Biol Chem 2013; 288:16451-16459. [PMID: 23625917 PMCID: PMC3675581 DOI: 10.1074/jbc.m112.442392] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 04/19/2013] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial outer membrane contains proteinaceous machineries for the import and assembly of proteins, including TOM (translocase of the outer membrane) and SAM (sorting and assembly machinery). It has been shown that the dimeric phospholipid cardiolipin is required for the stability of TOM and SAM complexes and thus for the efficient import and assembly of β-barrel proteins and some α-helical proteins of the outer membrane. Here, we report that mitochondria deficient in phosphatidylethanolamine (PE), the second non-bilayer-forming phospholipid, are impaired in the biogenesis of β-barrel proteins, but not of α-helical outer membrane proteins. The stability of TOM and SAM complexes is not disturbed by the lack of PE. By dissecting the import steps of β-barrel proteins, we show that an early import stage involving translocation through the TOM complex is affected. In PE-depleted mitochondria, the TOM complex binds precursor proteins with reduced efficiency. We conclude that PE is required for the proper function of the TOM complex.
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Affiliation(s)
- Thomas Becker
- Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, 79104 Freiburg, Germany
| | - Susanne E Horvath
- Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Institut für Biochemie, Technische Universität Graz, A-8010 Graz, Austria
| | - Lena Böttinger
- Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Fakultät für Biologie, Universität Freiburg, 79104 Freiburg, Germany
| | - Natalia Gebert
- Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany
| | - Günther Daum
- Institut für Biochemie, Technische Universität Graz, A-8010 Graz, Austria.
| | - Nikolaus Pfanner
- Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, 79104 Freiburg, Germany.
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34
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Couto N, Malys N, Gaskell SJ, Barber J. Partition and Turnover of Glutathione Reductase from Saccharomyces cerevisiae: A Proteomic Approach. J Proteome Res 2013; 12:2885-94. [DOI: 10.1021/pr4001948] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Narciso Couto
- Manchester
Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN,
United Kingdom
| | - Naglis Malys
- Manchester
Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN,
United Kingdom
| | - Simon J. Gaskell
- Manchester
Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN,
United Kingdom
| | - Jill Barber
- Manchester
Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN,
United Kingdom
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester M13 9PT, United
Kingdom
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35
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Baseler WA, Dabkowski ER, Jagannathan R, Thapa D, Nichols CE, Shepherd DL, Croston TL, Powell M, Razunguzwa TT, Lewis SE, Schnell DM, Hollander JM. Reversal of mitochondrial proteomic loss in Type 1 diabetic heart with overexpression of phospholipid hydroperoxide glutathione peroxidase. Am J Physiol Regul Integr Comp Physiol 2013; 304:R553-65. [PMID: 23408027 DOI: 10.1152/ajpregu.00249.2012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial dysfunction is a contributor to diabetic cardiomyopathy. Previously, we observed proteomic decrements within the inner mitochondrial membrane (IMM) and matrix of diabetic cardiac interfibrillar mitochondria (IFM) correlating with dysfunctional mitochondrial protein import. The goal of this study was to determine whether overexpression of mitochondria phospholipid hydroperoxide glutathione peroxidase 4 (mPHGPx), an antioxidant enzyme capable of scavenging membrane-associated lipid peroxides in the IMM, could reverse proteomic alterations, dysfunctional protein import, and ultimately, mitochondrial dysfunction associated with the diabetic heart. MPHGPx transgenic mice and controls were made diabetic by multiple low-dose streptozotocin injections and examined after 5 wk of hyperglycemia. Five weeks after hyperglycemia onset, in vivo analysis of cardiac contractile function revealed decreased ejection fraction and fractional shortening in diabetic hearts that was reversed with mPHGPx overexpression. MPHGPx overexpression increased electron transport chain function while attenuating hydrogen peroxide production and lipid peroxidation in diabetic mPHGPx IFM. MPHGPx overexpression lessened proteomic loss observed in diabetic IFM. Posttranslational modifications, including oxidations and deamidations, were attenuated in diabetic IFM with mPHGPx overexpression. Mitochondrial protein import dysfunction in diabetic IFM was reversed with mPHGPx overexpression correlating with protein import constituent preservation. Ingenuity Pathway Analyses indicated that oxidative phosphorylation, tricarboxylic acid cycle, and fatty acid oxidation processes most influenced in diabetic IFM were preserved by mPHGPx overexpression. Specific mitochondrial networks preserved included complex I and II, mitochondrial ultrastructure, and mitochondrial protein import. These results indicate that mPHGPx overexpression can preserve the mitochondrial proteome and provide cardioprotective benefits to the diabetic heart.
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Affiliation(s)
- Walter A Baseler
- Center for Cardiovascular and Respiratory Sciences, Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
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36
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Marada A, Allu PK, Murari A, PullaReddy B, Tammineni P, Thiriveedi VR, Danduprolu J, Sepuri NBV. Mge1, a nucleotide exchange factor of Hsp70, acts as an oxidative sensor to regulate mitochondrial Hsp70 function. Mol Biol Cell 2013; 24:692-703. [PMID: 23345595 PMCID: PMC3596242 DOI: 10.1091/mbc.e12-10-0719] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Yeast Mge1, the cochaperone of mitochondrial heat shock protein 70 (mHsp70), is essential for exchanging ATP for ADP on mHsp70 and thus for recycling of mHsp70 for mitochondrial protein import and folding. Mge1 acts as an oxidative sensor to regulate mHsp70 function. Despite the growing evidence of the role of oxidative stress in disease, its molecular mechanism of action remains poorly understood. The yeast Saccharomyces cerevisiae provides a valuable model system in which to elucidate the effects of oxidative stress on mitochondria in higher eukaryotes. Dimeric yeast Mge1, the cochaperone of heat shock protein 70 (Hsp70), is essential for exchanging ATP for ADP on Hsp70 and thus for recycling of Hsp70 for mitochondrial protein import and folding. Here we show an oxidative stress–dependent decrease in Mge1 dimer formation accompanied by a concomitant decrease in Mge1–Hsp70 complex formation in vitro. The Mge1-M155L substitution mutant stabilizes both Mge1 dimer and Mge1–Hsp70 complex formation. Most important, the Mge1-M155L mutant rescues the slow-growth phenomenon associated with the wild-type Mge1 strain in the presence of H2O2 in vivo, stimulation of the ATPase activity of Hsp70, and the protein import defect during oxidative stress in vitro. Furthermore, cross-linking studies reveal that Mge1–Hsp70 complex formation in mitochondria isolated from wild-type Mge1 cells is more susceptible to reactive oxygen species compared with mitochondria from Mge1-M155L cells. This novel oxidative sensor capability of yeast Mge1 might represent an evolutionarily conserved function, given that human recombinant dimeric Mge1 is also sensitive to H2O2.
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Affiliation(s)
- Adinarayana Marada
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
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37
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Sztolsztener ME, Brewinska A, Guiard B, Chacinska A. Disulfide bond formation: sulfhydryl oxidase ALR controls mitochondrial biogenesis of human MIA40. Traffic 2012. [PMID: 23186364 DOI: 10.1111/tra.12030] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The conserved MIA pathway is responsible for the import and oxidative folding of proteins destined for the intermembrane space of mitochondria. In contrast to a wealth of information obtained from studies with yeast, the function of the MIA pathway in higher eukaryotes has remained enigmatic. Here, we took advantage of the molecular understanding of the MIA pathway in yeast and designed a model of the human MIA pathway. The yeast model for MIA consists of two critical components, the disulfide bond carrier Mia40 and sulfhydryl oxidase Erv1/ALR. Human MIA40 and ALR substituted for their yeast counterparts in the essential function for the oxidative biogenesis of mitochondrial intermembrane space proteins. In addition, the sulfhydryl oxidases ALR/Erv1 were found to be involved in the mitochondrial localization of human MIA40. Furthermore, the defective accumulation of human MIA40 in mitochondria underlies a recently identified disease that is caused by amino acid exchange in ALR. Thus, human ALR is an important factor that controls not only the ability of MIA40 to bind and oxidize protein clients but also the localization of human MIA40 in mitochondria.
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Affiliation(s)
- Malgorzata E Sztolsztener
- International Institute of Molecular and Cell Biology, Laboratory of Mitochondrial Biogenesis Warsaw, 02-109, Poland
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38
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Stroud DA, Formosa LE, Wijeyeratne XW, Nguyen TN, Ryan MT. Gene knockout using transcription activator-like effector nucleases (TALENs) reveals that human NDUFA9 protein is essential for stabilizing the junction between membrane and matrix arms of complex I. J Biol Chem 2012; 288:1685-90. [PMID: 23223238 DOI: 10.1074/jbc.c112.436766] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription activator-like effector nucleases (TALENs) represent a promising approach for targeted knock-out of genes in cultured human cells. We used TALEN-technology to knock out the nuclear gene encoding NDUFA9, a subunit of mitochondrial respiratory chain complex I in HEK293T cells. Screening for the knock-out revealed a mixture of NDUFA9 cell clones that harbored partial deletions of the mitochondrial N-terminal targeting signal but were still capable of import. A cell line lacking functional copies of both NDUFA9 alleles resulted in a loss of NDUFA9 protein expression, impaired assembly of complex I, and cells incapable of growth in galactose medium. Cells lacking NDUFA9 contained a complex I subcomplex consisting of membrane arm subunits but not marker subunits of the matrix arm. Re-expression of NDUFA9 restored the defects in complex I assembly. We conclude that NDUFA9 is involved in stabilizing the junction between membrane and matrix arms of complex I, a late assembly step critical for complex I biogenesis and activity.
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Affiliation(s)
- David A Stroud
- Department of Biochemistry, La Trobe Institute for Molecular Science, and ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne 3086, Australia
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39
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Horvath SE, Böttinger L, Vögtle FN, Wiedemann N, Meisinger C, Becker T, Daum G. Processing and topology of the yeast mitochondrial phosphatidylserine decarboxylase 1. J Biol Chem 2012; 287:36744-55. [PMID: 22984266 PMCID: PMC3481278 DOI: 10.1074/jbc.m112.398107] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/04/2012] [Indexed: 11/06/2022] Open
Abstract
The inner mitochondrial membrane plays a crucial role in cellular lipid homeostasis through biosynthesis of the non-bilayer-forming lipids phosphatidylethanolamine and cardiolipin. In the yeast Saccharomyces cerevisiae, the majority of cellular phosphatidylethanolamine is synthesized by the mitochondrial phosphatidylserine decarboxylase 1 (Psd1). The biogenesis of Psd1 involves several processing steps. It was speculated that the Psd1 precursor is sorted into the inner membrane and is subsequently released into the intermembrane space by proteolytic removal of a hydrophobic sorting signal. However, components involved in the maturation of the Psd1 precursor have not been identified. We show that processing of Psd1 involves the action of the mitochondrial processing peptidase and Oct1 and an autocatalytic cleavage at a highly conserved LGST motif yielding the α- and β-subunit of the enzyme. The Psd1 β-subunit (Psd1β) forms the membrane anchor, which binds the intermembrane space-localized α-subunit (Psd1α). Deletion of a transmembrane segment in the β-subunit results in mislocalization of Psd1 and reduced enzymatic activity. Surprisingly, autocatalytic cleavage does not depend on proper localization to the inner mitochondrial membrane. In summary, membrane integration of Psd1 is crucial for its functionality and for maintenance of mitochondrial lipid homeostasis.
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Affiliation(s)
- Susanne E. Horvath
- From the Institut für Biochemie, Technische Universität Graz, Petersgasse 12/2, A-8010 Graz, Austria
- the Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
| | - Lena Böttinger
- the Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
- the Fakultät für Biologie, Universität Freiburg, D-79104 Freiburg, Germany, and
| | - F.-Nora Vögtle
- the Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
- the BIOSS Centre for Biological Signalling Studies, Universität Freiburg, D-79104 Freiburg, Germany
| | - Nils Wiedemann
- the Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
- the BIOSS Centre for Biological Signalling Studies, Universität Freiburg, D-79104 Freiburg, Germany
| | - Chris Meisinger
- the Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
- the BIOSS Centre for Biological Signalling Studies, Universität Freiburg, D-79104 Freiburg, Germany
| | - Thomas Becker
- the Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
- the BIOSS Centre for Biological Signalling Studies, Universität Freiburg, D-79104 Freiburg, Germany
| | - Günther Daum
- From the Institut für Biochemie, Technische Universität Graz, Petersgasse 12/2, A-8010 Graz, Austria
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40
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Baker MJ, Mooga VP, Guiard B, Langer T, Ryan MT, Stojanovski D. Impaired folding of the mitochondrial small TIM chaperones induces clearance by the i-AAA protease. J Mol Biol 2012; 424:227-39. [PMID: 23036860 DOI: 10.1016/j.jmb.2012.09.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/14/2012] [Accepted: 09/17/2012] [Indexed: 11/24/2022]
Abstract
The intermembrane space of mitochondria contains a dedicated chaperone network-the small translocase of the inner membrane (TIM) family-for the sorting of hydrophobic precursors. All small TIMs are defined by the presence of a twin CX(3)C motif and the monomeric proteins are stabilized by two intramolecular disulfide bonds formed between the cysteines of these motifs. The conserved cysteine residues within small TIM members have also been shown to participate in early biogenesis events, with the most N-terminal cysteine residue important for import and retention within the intermembrane space via the receptor and disulfide oxidase, Mia40. In this study, we have analyzed the in vivo consequences of improper folding of small TIM chaperones by generating site-specific cysteine mutants and assessed the fate of the incompletely oxidized proteins within mitochondria. We show that no individual cysteine residue is required for the function of Tim9 or Tim10 in yeast and that defective assembly of the small TIMs induces their proteolytic clearance from mitochondria. We delineate a clearance mechanism for the mutant proteins and their unassembled wild-type partner protein by the mitochondrial ATP-dependent protease, Yme1 (yeast mitochondrial escape 1).
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Affiliation(s)
- Michael J Baker
- Department of Biochemistry, La Trobe Institute for Molecular Science and ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne 3086, Australia
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41
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Böttinger L, Horvath SE, Kleinschroth T, Hunte C, Daum G, Pfanner N, Becker T. Phosphatidylethanolamine and cardiolipin differentially affect the stability of mitochondrial respiratory chain supercomplexes. J Mol Biol 2012; 423:677-86. [PMID: 22971339 PMCID: PMC3480645 DOI: 10.1016/j.jmb.2012.09.001] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 08/11/2012] [Accepted: 09/04/2012] [Indexed: 12/30/2022]
Abstract
The mitochondrial inner membrane contains two non-bilayer‐forming phospholipids, phosphatidylethanolamine (PE) and cardiolipin (CL). Lack of CL leads to destabilization of respiratory chain supercomplexes, a reduced activity of cytochrome c oxidase, and a reduced inner membrane potential Δψ. Although PE is more abundant than CL in the mitochondrial inner membrane, its role in biogenesis and assembly of inner membrane complexes is unknown. We report that similar to the lack of CL, PE depletion resulted in a decrease of Δψ and thus in an impaired import of preproteins into and across the inner membrane. The respiratory capacity and in particular the activity of cytochrome c oxidase were impaired in PE-depleted mitochondria, leading to the decrease of Δψ. In contrast to depletion of CL, depletion of PE did not destabilize respiratory chain supercomplexes but favored the formation of larger supercomplexes (megacomplexes) between the cytochrome bc1 complex and the cytochrome c oxidase. We conclude that both PE and CL are required for a full activity of the mitochondrial respiratory chain and the efficient generation of the inner membrane potential. The mechanisms, however, are different since these non-bilayer‐forming phospholipids exert opposite effects on the stability of respiratory chain supercomplexes.
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Affiliation(s)
- Lena Böttinger
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, D-79104 Freiburg, Germany
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42
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Zerbes RM, Bohnert M, Stroud DA, von der Malsburg K, Kram A, Oeljeklaus S, Warscheid B, Becker T, Wiedemann N, Veenhuis M, van der Klei IJ, Pfanner N, van der Laan M. Role of MINOS in Mitochondrial Membrane Architecture: Cristae Morphology and Outer Membrane Interactions Differentially Depend on Mitofilin Domains. J Mol Biol 2012; 422:183-91. [DOI: 10.1016/j.jmb.2012.05.004] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/01/2012] [Accepted: 05/01/2012] [Indexed: 12/26/2022]
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43
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Bohnert M, Wenz LS, Zerbes RM, Horvath SE, Stroud DA, von der Malsburg K, Müller JM, Oeljeklaus S, Perschil I, Warscheid B, Chacinska A, Veenhuis M, van der Klei IJ, Daum G, Wiedemann N, Becker T, Pfanner N, van der Laan M. Role of mitochondrial inner membrane organizing system in protein biogenesis of the mitochondrial outer membrane. Mol Biol Cell 2012; 23:3948-56. [PMID: 22918945 PMCID: PMC3469511 DOI: 10.1091/mbc.e12-04-0295] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mitochondrial inner membrane organizing system (MINOS) is a large protein complex required for maintaining inner membrane architecture. We report that MINOS independently interacts with both preprotein translocases of the outer mitochondrial membrane and plays a role in the biogenesis of β-barrel proteins of the outer membrane. Mitochondria contain two membranes, the outer membrane and the inner membrane with folded cristae. The mitochondrial inner membrane organizing system (MINOS) is a large protein complex required for maintaining inner membrane architecture. MINOS interacts with both preprotein transport machineries of the outer membrane, the translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). It is unknown, however, whether MINOS plays a role in the biogenesis of outer membrane proteins. We have dissected the interaction of MINOS with TOM and SAM and report that MINOS binds to both translocases independently. MINOS binds to the SAM complex via the conserved polypeptide transport–associated domain of Sam50. Mitochondria lacking mitofilin, the large core subunit of MINOS, are impaired in the biogenesis of β-barrel proteins of the outer membrane, whereas mutant mitochondria lacking any of the other five MINOS subunits import β-barrel proteins in a manner similar to wild-type mitochondria. We show that mitofilin is required at an early stage of β-barrel biogenesis that includes the initial translocation through the TOM complex. We conclude that MINOS interacts with TOM and SAM independently and that the core subunit mitofilin is involved in biogenesis of outer membrane β-barrel proteins.
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Affiliation(s)
- Maria Bohnert
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
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44
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Pusnik M, Mani J, Schmidt O, Niemann M, Oeljeklaus S, Schnarwiler F, Warscheid B, Lithgow T, Meisinger C, Schneider A. An essential novel component of the noncanonical mitochondrial outer membrane protein import system of trypanosomatids. Mol Biol Cell 2012; 23:3420-8. [PMID: 22787278 PMCID: PMC3431924 DOI: 10.1091/mbc.e12-02-0107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The mitochondrial outer membrane protein Tom40 is the general entry gate for imported proteins in essentially all eukaryotes. Trypanosomatids lack Tom40, however, and use instead a protein termed the archaic translocase of the outer mitochondrial membrane (ATOM). Here we report the discovery of pATOM36, a novel essential component of the trypanosomal outer membrane protein import system that interacts with ATOM. pATOM36 is not related to known Tom proteins from other organisms and mediates the import of matrix proteins. However, there is a group of precursor proteins whose import is independent of pATOM36. Domain-swapping experiments indicate that the N-terminal presequence-containing domain of the substrate proteins at least in part determines the dependence on pATOM36. Secondary structure profiling suggests that pATOM36 is composed largely of α-helices and its assembly into the outer membrane is independent of the sorting and assembly machinery complex. Taken together, these results show that pATOM36 is a novel component associated with the ATOM complex that promotes the import of a subpopulation of proteins into the mitochondrial matrix.
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Affiliation(s)
- Mascha Pusnik
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland
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45
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Gebert M, Schrempp SG, Mehnert CS, Heißwolf AK, Oeljeklaus S, Ieva R, Bohnert M, von der Malsburg K, Wiese S, Kleinschroth T, Hunte C, Meyer HE, Haferkamp I, Guiard B, Warscheid B, Pfanner N, van der Laan M. Mgr2 promotes coupling of the mitochondrial presequence translocase to partner complexes. ACTA ACUST UNITED AC 2012; 197:595-604. [PMID: 22613836 PMCID: PMC3365495 DOI: 10.1083/jcb.201110047] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Many mitochondrial proteins are synthesized with N-terminal presequences in the cytosol. The presequence translocase of the inner mitochondrial membrane (TIM23) translocates preproteins into and across the membrane and associates with the matrix-localized import motor. The TIM23 complex consists of three core components and Tim21, which interacts with the translocase of the outer membrane (TOM) and the respiratory chain. We have identified a new subunit of the TIM23 complex, the inner membrane protein Mgr2. Mitochondria lacking Mgr2 were deficient in the Tim21-containing sorting form of the TIM23 complex. Mgr2 was required for binding of Tim21 to TIM23(CORE), revealing a binding chain of TIM23(CORE)-Mgr2/Tim21-respiratory chain. Mgr2-deficient yeast cells were defective in growth at elevated temperature, and the mitochondria were impaired in TOM-TIM23 coupling and the import of presequence-carrying preproteins. We conclude that Mgr2 is a coupling factor of the presequence translocase crucial for cell growth at elevated temperature and for efficient protein import.
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Affiliation(s)
- Michael Gebert
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Fakultät für Biologie, Funktionelle Proteomik, Universität Freiburg, 79104 Freiburg, Germany
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Rao S, Schmidt O, Harbauer AB, Schönfisch B, Guiard B, Pfanner N, Meisinger C. Biogenesis of the preprotein translocase of the outer mitochondrial membrane: protein kinase A phosphorylates the precursor of Tom40 and impairs its import. Mol Biol Cell 2012; 23:1618-27. [PMID: 22419819 PMCID: PMC3338429 DOI: 10.1091/mbc.e11-11-0933] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The translocase of the outer mitochondrial membrane (TOM) is essential for the import of proteins into mitochondria. Cytosolic protein kinase A phosphorylates the precursor of the channel-forming protein Tom40 and inhibits its import into mitochondria, thus regulating the biogenesis of the protein entry gate of mitochondria. The preprotein translocase of the outer mitochondrial membrane (TOM) functions as the main entry gate for the import of nuclear-encoded proteins into mitochondria. The major subunits of the TOM complex are the three receptors Tom20, Tom22, and Tom70 and the central channel-forming protein Tom40. Cytosolic kinases have been shown to regulate the biogenesis and activity of the Tom receptors. Casein kinase 2 stimulates the biogenesis of Tom22 and Tom20, whereas protein kinase A (PKA) impairs the receptor function of Tom70. Here we report that PKA exerts an inhibitory effect on the biogenesis of the β-barrel protein Tom40. Tom40 is synthesized as precursor on cytosolic ribosomes and subsequently imported into mitochondria. We show that PKA phosphorylates the precursor of Tom40. The phosphorylated Tom40 precursor is impaired in import into mitochondria, whereas the nonphosphorylated precursor is efficiently imported. We conclude that PKA plays a dual role in the regulation of the TOM complex. Phosphorylation by PKA not only impairs the receptor activity of Tom70, but it also inhibits the biogenesis of the channel protein Tom40.
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Affiliation(s)
- Sanjana Rao
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Universität Freiburg, 79104 Freiburg, Germany
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Lazarou M, Jin SM, Kane LA, Youle RJ. Role of PINK1 binding to the TOM complex and alternate intracellular membranes in recruitment and activation of the E3 ligase Parkin. Dev Cell 2012; 22:320-33. [PMID: 22280891 DOI: 10.1016/j.devcel.2011.12.014] [Citation(s) in RCA: 459] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 11/08/2011] [Accepted: 12/21/2011] [Indexed: 10/14/2022]
Abstract
Mutations in the mitochondrial kinase PINK1 and the cytosolic E3 ligase Parkin can cause Parkinson's disease. Damaged mitochondria accumulate PINK1 on the outer membrane where, dependent on kinase activity, it recruits and activates Parkin to induce mitophagy, potentially maintaining organelle fidelity. How PINK1 recruits Parkin is unknown. We show that endogenous PINK1 forms a 700 kDa complex with the translocase of the outer membrane (TOM) selectively on depolarized mitochondria whereas PINK1 ectopically targeted to the outer membrane retains association with TOM on polarized mitochondria. Inducibly targeting PINK1 to peroxisomes or lysosomes, which lack a TOM complex, recruits Parkin and activates ubiquitin ligase activity on the respective organelles. Once there, Parkin induces organelle selective autophagy of peroxisomes but not lysosomes. We propose that the association of PINK1 with the TOM complex allows rapid reimport of PINK1 to rescue repolarized mitochondria from mitophagy, and discount mitochondrial-specific factors for Parkin translocation and activation.
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Affiliation(s)
- Michael Lazarou
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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Gebert N, Gebert M, Oeljeklaus S, von der Malsburg K, Stroud D, Kulawiak B, Wirth C, Zahedi R, Dolezal P, Wiese S, Simon O, Schulze-Specking A, Truscott K, Sickmann A, Rehling P, Guiard B, Hunte C, Warscheid B, van der Laan M, Pfanner N, Wiedemann N. Dual Function of Sdh3 in the Respiratory Chain and TIM22 Protein Translocase of the Mitochondrial Inner Membrane. Mol Cell 2011; 44:811-8. [DOI: 10.1016/j.molcel.2011.09.025] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 08/18/2011] [Accepted: 09/20/2011] [Indexed: 10/14/2022]
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Schulz C, Lytovchenko O, Melin J, Chacinska A, Guiard B, Neumann P, Ficner R, Jahn O, Schmidt B, Rehling P. Tim50's presequence receptor domain is essential for signal driven transport across the TIM23 complex. ACTA ACUST UNITED AC 2011; 195:643-56. [PMID: 22065641 PMCID: PMC3257539 DOI: 10.1083/jcb.201105098] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
N-terminal targeting signals (presequences) direct proteins across the TOM complex in the outer mitochondrial membrane and the TIM23 complex in the inner mitochondrial membrane. Presequences provide directionality to the transport process and regulate the transport machineries during translocation. However, surprisingly little is known about how presequence receptors interact with the signals and what role these interactions play during preprotein transport. Here, we identify signal-binding sites of presequence receptors through photo-affinity labeling. Using engineered presequence probes, photo cross-linking sites on mitochondrial proteins were mapped mass spectrometrically, thereby defining a presequence-binding domain of Tim50, a core subunit of the TIM23 complex that is essential for mitochondrial protein import. Our results establish Tim50 as the primary presequence receptor at the inner membrane and show that targeting signals and Tim50 regulate the Tim23 channel in an antagonistic manner.
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Affiliation(s)
- Christian Schulz
- Abteilung für Biochemie II, Universität Göttingen, D-37073 Göttingen, Germany
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50
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A trypanosomal pentatricopeptide repeat protein stabilizes the mitochondrial mRNAs of cytochrome oxidase subunits 1 and 2. EUKARYOTIC CELL 2011; 11:79-87. [PMID: 22058141 DOI: 10.1128/ec.05213-11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The pentatricopeptide repeat (PPR) protein family consists of organellar proteins predicted to bind to specific RNA sequences. Plants have hundreds of distinct PPR proteins, whereas other eukaryotes generally have many fewer. The genome of the parasitic protozoon Trypanosoma brucei is predicted to encode more than 30 different PPR proteins, which is an extraordinarily high number for a nonplant organism. Here we report the characterization T. brucei PPR9 (TbPPR9). Epitope tagging shows that the protein is exclusively mitochondrially localized. Interestingly, while in induced RNA interference cell lines TbPPR9 is efficiently downregulated, the level of its mRNA is not affected. Ablation of TbPPR9 selectively abolishes oxidative but not mitochondrial substrate-level phosphorylation. The molecular basis of this phenotype is the fact that TbPPR9 is required for the stability of the cytochrome oxidase subunit 1 (COX1) and COX2 mRNAs. This is supported by the observation that ablation of TbPPR9 destabilizes the COX complex but not the cytochrome bc1 or the ATP synthase complex. Moreover, it was shown by blue native gel electrophoresis that TbPPR9 is present in a large complex of unknown composition.
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