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Fielden LF, Busch JD, Merkt SG, Ganesan I, Steiert C, Hasselblatt HB, Busto JV, Wirth C, Zufall N, Jungbluth S, Noll K, Dung JM, Butenko L, von der Malsburg K, Koch HG, Hunte C, van der Laan M, Wiedemann N. Central role of Tim17 in mitochondrial presequence protein translocation. Nature 2023; 621:627-634. [PMID: 37527780 PMCID: PMC10511324 DOI: 10.1038/s41586-023-06477-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 07/25/2023] [Indexed: 08/03/2023]
Abstract
The presequence translocase of the mitochondrial inner membrane (TIM23) represents the major route for the import of nuclear-encoded proteins into mitochondria1,2. About 60% of more than 1,000 different mitochondrial proteins are synthesized with amino-terminal targeting signals, termed presequences, which form positively charged amphiphilic α-helices3,4. TIM23 sorts the presequence proteins into the inner membrane or matrix. Various views, including regulatory and coupling functions, have been reported on the essential TIM23 subunit Tim17 (refs. 5-7). Here we mapped the interaction of Tim17 with matrix-targeted and inner membrane-sorted preproteins during translocation in the native membrane environment. We show that Tim17 contains conserved negative charges close to the intermembrane space side of the bilayer, which are essential to initiate presequence protein translocation along a distinct transmembrane cavity of Tim17 for both classes of preproteins. The amphiphilic character of mitochondrial presequences directly matches this Tim17-dependent translocation mechanism. This mechanism permits direct lateral release of transmembrane segments of inner membrane-sorted precursors into the inner membrane.
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Affiliation(s)
- Laura F Fielden
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jakob D Busch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sandra G Merkt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Iniyan Ganesan
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Conny Steiert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hanna B Hasselblatt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jon V Busto
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christophe Wirth
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nicole Zufall
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sibylle Jungbluth
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Katja Noll
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Julia M Dung
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ludmila Butenko
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Karina von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Hans-Georg Koch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Carola Hunte
- 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
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany.
| | - Nils Wiedemann
- 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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2
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Bock-Bierbaum T, Funck K, Wollweber F, Lisicki E, von der Malsburg K, von der Malsburg A, Laborenz J, Noel JK, Hessenberger M, Jungbluth S, Bernert C, Kunz S, Riedel D, Lilie H, Jakobs S, van der Laan M, Daumke O. Structural insights into crista junction formation by the Mic60-Mic19 complex. Sci Adv 2022; 8:eabo4946. [PMID: 36044574 PMCID: PMC9432830 DOI: 10.1126/sciadv.abo4946] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Mitochondrial cristae membranes are the oxidative phosphorylation sites in cells. Crista junctions (CJs) form the highly curved neck regions of cristae and are thought to function as selective entry gates into the cristae space. Little is known about how CJs are generated and maintained. We show that the central coiled-coil (CC) domain of the mitochondrial contact site and cristae organizing system subunit Mic60 forms an elongated, bow tie-shaped tetrameric assembly. Mic19 promotes Mic60 tetramerization via a conserved interface between the Mic60 mitofilin and Mic19 CHCH (CC-helix-CC-helix) domains. Dimerization of mitofilin domains exposes a crescent-shaped membrane-binding site with convex curvature tailored to interact with the curved CJ neck. Our study suggests that the Mic60-Mic19 subcomplex traverses CJs as a molecular strut, thereby controlling CJ architecture and function.
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Affiliation(s)
- Tobias Bock-Bierbaum
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Kathrin Funck
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Florian Wollweber
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University Medical School, Homburg, Saarland, Germany
| | - Elisa Lisicki
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Karina von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University Medical School, Homburg, Saarland, Germany
| | - Alexander von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University Medical School, Homburg, Saarland, Germany
| | - Janina Laborenz
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University Medical School, Homburg, Saarland, Germany
| | - Jeffrey K. Noel
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Manuel Hessenberger
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Sibylle Jungbluth
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University Medical School, Homburg, Saarland, Germany
| | - Carola Bernert
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Séverine Kunz
- Technology Platform for Electron Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Dietmar Riedel
- Laboratory of Electron Microscopy, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Hauke Lilie
- Institute of Biochemistry and Biotechnology, Section of Protein Biochemistry, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Stefan Jakobs
- Research Group Mitochondrial Structure and Dynamics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Clinic for Neurology, University Medical Center Göttingen, Göttingen, Germany
- Translational Neuroinflammation and Automated Microscopy, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Göttingen, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University Medical School, Homburg, Saarland, Germany
| | - Oliver Daumke
- Structural Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
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3
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Bertero E, Nickel A, Kohlhaas M, Hohl M, Sequeira V, Brune C, Schwemmlein J, Abeßer M, Schuh K, Kutschka I, Carlein C, Münker K, Atighetchi S, Müller A, Kazakov A, Kappl R, von der Malsburg K, van der Laan M, Schiuma AF, Böhm M, Laufs U, Hoth M, Rehling P, Kuhn M, Dudek J, von der Malsburg A, Prates Roma L, Maack C. Loss of Mitochondrial Ca 2+ Uniporter Limits Inotropic Reserve and Provides Trigger and Substrate for Arrhythmias in Barth Syndrome Cardiomyopathy. Circulation 2021; 144:1694-1713. [PMID: 34648376 DOI: 10.1161/circulationaha.121.053755] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Barth syndrome (BTHS) is caused by mutations of the gene encoding tafazzin, which catalyzes maturation of mitochondrial cardiolipin and often manifests with systolic dysfunction during early infancy. Beyond the first months of life, BTHS cardiomyopathy typically transitions to a phenotype of diastolic dysfunction with preserved ejection fraction, blunted contractile reserve during exercise, and arrhythmic vulnerability. Previous studies traced BTHS cardiomyopathy to mitochondrial formation of reactive oxygen species (ROS). Because mitochondrial function and ROS formation are regulated by excitation-contraction coupling, integrated analysis of mechano-energetic coupling is required to delineate the pathomechanisms of BTHS cardiomyopathy. METHODS We analyzed cardiac function and structure in a mouse model with global knockdown of tafazzin (Taz-KD) compared with wild-type littermates. Respiratory chain assembly and function, ROS emission, and Ca2+ uptake were determined in isolated mitochondria. Excitation-contraction coupling was integrated with mitochondrial redox state, ROS, and Ca2+ uptake in isolated, unloaded or preloaded cardiac myocytes, and cardiac hemodynamics analyzed in vivo. RESULTS Taz-KD mice develop heart failure with preserved ejection fraction (>50%) and age-dependent progression of diastolic dysfunction in the absence of fibrosis. Increased myofilament Ca2+ affinity and slowed cross-bridge cycling caused diastolic dysfunction, in part, compensated by accelerated diastolic Ca2+ decay through preactivated sarcoplasmic reticulum Ca2+-ATPase. Taz deficiency provoked heart-specific loss of mitochondrial Ca2+ uniporter protein that prevented Ca2+-induced activation of the Krebs cycle during β-adrenergic stimulation, oxidizing pyridine nucleotides and triggering arrhythmias in cardiac myocytes. In vivo, Taz-KD mice displayed prolonged QRS duration as a substrate for arrhythmias, and a lack of inotropic response to β-adrenergic stimulation. Cellular arrhythmias and QRS prolongation, but not the defective inotropic reserve, were restored by inhibiting Ca2+ export through the mitochondrial Na+/Ca2+ exchanger. All alterations occurred in the absence of excess mitochondrial ROS in vitro or in vivo. CONCLUSIONS Downregulation of mitochondrial Ca2+ uniporter, increased myofilament Ca2+ affinity, and preactivated sarcoplasmic reticulum Ca2+-ATPase provoke mechano-energetic uncoupling that explains diastolic dysfunction and the lack of inotropic reserve in BTHS cardiomyopathy. Furthermore, defective mitochondrial Ca2+ uptake provides a trigger and a substrate for ventricular arrhythmias. These insights can guide the ongoing search for a cure of this orphaned disease.
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Affiliation(s)
- Edoardo Bertero
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Now with Department of Internal Medicine and Specialties (Di.M.I.), University of Genoa, Italy (E.B.)
| | - Alexander Nickel
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Michael Kohlhaas
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Mathias Hohl
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Vasco Sequeira
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Carolin Brune
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Julia Schwemmlein
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Marco Abeßer
- Institute of Physiology, University of Würzburg, Germany (M.A., K.S., M. Kuhn)
| | - Kai Schuh
- Institute of Physiology, University of Würzburg, Germany (M.A., K.S., M. Kuhn)
| | - Ilona Kutschka
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Christopher Carlein
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Kai Münker
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Sarah Atighetchi
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Andreas Müller
- Clinic for Radiology (A.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Andrey Kazakov
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Reinhard Kappl
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Karina von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine (K.v.d.M., M.v.d.L., A.v.d.M.), Saarland University, Homburg/Saar, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine (K.v.d.M., M.v.d.L., A.v.d.M.), Saarland University, Homburg/Saar, Germany
| | - Anna-Florentine Schiuma
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Michael Böhm
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Ulrich Laufs
- Now with Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig, Germany (U.L.)
| | - Markus Hoth
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, Georg-August University, Göttingen, Germany (P.R., J.D.).,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Germany (P.R.).,Max-Planck Institute for Biophysical Chemistry, Göttingen, Germany (P.R.)
| | - Michaela Kuhn
- Institute of Physiology, University of Würzburg, Germany (M.A., K.S., M. Kuhn)
| | - Jan Dudek
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Department of Cellular Biochemistry, Georg-August University, Göttingen, Germany (P.R., J.D.)
| | - Alexander von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine (K.v.d.M., M.v.d.L., A.v.d.M.), Saarland University, Homburg/Saar, Germany
| | - Leticia Prates Roma
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Christoph Maack
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany.,Department for Internal Medicine 1, University Clinic Würzburg, Germany (C.M.)
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4
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Turakhiya U, von der Malsburg K, Gold VAM, Guiard B, Chacinska A, van der Laan M, Ieva R. Protein Import by the Mitochondrial Presequence Translocase in the Absence of a Membrane Potential. J Mol Biol 2016; 428:1041-1052. [PMID: 26827728 DOI: 10.1016/j.jmb.2016.01.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/15/2015] [Accepted: 01/01/2016] [Indexed: 11/17/2022]
Abstract
The highly organized mitochondrial inner membrane harbors enzymes that produce the bulk of cellular ATP via oxidative phosphorylation. The majority of inner membrane protein precursors are synthesized in the cytosol. Precursors with a cleavable presequence are imported by the presequence translocase (TIM23 complex), while other precursors containing internal targeting signals are imported by the carrier translocase (TIM22 complex). Both TIM23 and TIM22 are activated by the transmembrane electrochemical potential. Many small inner membrane proteins, however, do not resemble canonical TIM23 or TIM22 substrates and their mechanism of import is unknown. We report that subunit e of the F1Fo-ATP synthase, a small single-spanning inner membrane protein that is critical for inner membrane organization, is imported by TIM23 in a process that does not require activation by the membrane potential. Absence of positively charged residues at the matrix-facing amino-terminus of subunit e facilitates membrane potential-independent import. Instead, engineered positive charges establish a dependence of the import reaction on the electrochemical potential. Our results have two major implications. First, they reveal an unprecedented pathway of protein import into the mitochondrial inner membrane, which is mediated by TIM23. Second, they directly demonstrate the role of the membrane potential in driving the electrophoretic transport of positively charged protein segments across the inner membrane.
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Affiliation(s)
- Uma Turakhiya
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Spemann Graduate School for Biology and Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Karina von der Malsburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Vicki A M Gold
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Bernard Guiard
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France
| | - Agnieszka Chacinska
- International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Martin van der Laan
- 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; Medical Biochemistry and Molecular Biology, Saarland University, 66421 Homburg, Germany
| | - Raffaele Ieva
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Laboratoire de Microbiologie et Génétique Moléculaire, Centre National de la Recherche Scientifique, Université Paul Sabatier, 31077 Toulouse, France.
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5
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von der Malsburg K, Shao S, Hegde RS. The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon. Mol Biol Cell 2015; 26:2168-80. [PMID: 25877867 PMCID: PMC4462936 DOI: 10.1091/mbc.e15-01-0040] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/09/2015] [Indexed: 11/11/2022] Open
Abstract
Secretory proteins that stall during their translocation into the endoplasmic reticulum can be polyubiquitinated by a ribosome-associated quality control pathway that accesses its targets via a gap at the ribosome–translocon junction. This pathway may help resolve blocked translocons and efficiently degrade unfinished proteins. Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome–Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S–RQC and 80S–Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome–translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel.
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Affiliation(s)
| | - Sichen Shao
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ramanujan S Hegde
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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6
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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7
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Lytovchenko O, Naumenko N, Oeljeklaus S, Schmidt B, von der Malsburg K, Deckers M, Warscheid B, van der Laan M, Rehling P. The INA complex facilitates assembly of the peripheral stalk of the mitochondrial F1Fo-ATP synthase. EMBO J 2014; 33:1624-38. [PMID: 24942160 DOI: 10.15252/embj.201488076] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial F1Fo-ATP synthase generates the bulk of cellular ATP. This molecular machine assembles from nuclear- and mitochondria-encoded subunits. Whereas chaperones for formation of the matrix-exposed hexameric F1-ATPase core domain have been identified, insight into how the nuclear-encoded F1-domain assembles with the membrane-embedded Fo-region is lacking. Here we identified the INA complex (INAC) in the inner membrane of mitochondria as an assembly factor involved in this process. Ina22 and Ina17 are INAC constituents that physically associate with the F1-module and peripheral stalk, but not with the assembled F1Fo-ATP synthase. Our analyses show that loss of Ina22 and Ina17 specifically impairs formation of the peripheral stalk that connects the catalytic F1-module to the membrane embedded Fo-domain. We conclude that INAC represents a matrix-exposed inner membrane protein complex that facilitates peripheral stalk assembly and thus promotes a key step in the biogenesis of mitochondrial F1Fo-ATP synthase.
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Affiliation(s)
- Oleksandr Lytovchenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Nataliia Naumenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty for Biology, University of Freiburg, Freiburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Bernhard Schmidt
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Karina von der Malsburg
- Institute for Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, Freiburg, Germany
| | - Markus Deckers
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty for Biology, University of Freiburg, Freiburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Martin van der Laan
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany Institute for Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, Freiburg, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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8
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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] [What about the content of this article? (0)] [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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9
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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11
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Kohl C, Tessarz P, von der Malsburg K, Zahn R, Bukau B, Mogk A. Cooperative and independent activities of Sgt2 and Get5 in the targeting of tail-anchored proteins. Biol Chem 2011; 392:601-8. [DOI: 10.1515/bc.2011.066] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
TPR proteins modulate the activity of molecular chaperones. Here, we describe the S. cerevisiae TPR protein Sgt2 as interaction partner of Ssa1 and Hsp104 and as a component of the GET pathway by interacting with Get5. The GET pathway mediates the sorting of tail-anchored (TA) proteins, harboring a C-terminal trans-membrane segment, to the ER membrane. S. cerevisiae sgt2Δ cells show partial defects in TA protein sorting. Sgt2 activity in vivo relies on its N- and C-terminal domains, whereas the central TPR domain and thus chaperone interactions are dispensable. We show that TA protein sorting defects are more severe in sgt2Δ get5Δ mutants compared to single knockouts. Furthermore, overproduction of Sgt2 becomes toxic to get3Δ but not to get5Δ cells. Together, these findings indicate an additional, Get5-independent role of Sgt2 in TA protein sorting, pointing to parallel pathways of substrate delivery to Get3.
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