The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins
Summary: The mitochondrial outer membrane contains integral proteins with α-helical membrane anchors or a transmembrane β-barrel. The translocase of the outer membrane (TOM) cooperates with the sorting and assembly machinery (SAM) in the import of β-barrel proteins, whereas the mitochondrial import...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020-04-01
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| Series: | Cell Reports |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211124720305167 |
| _version_ | 1811290008309465088 |
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| author | Kim Nguyen Doan Alexander Grevel Christoph U. Mårtensson Lars Ellenrieder Nicolas Thornton Lena-Sophie Wenz Łukasz Opaliński Bernard Guiard Nikolaus Pfanner Thomas Becker |
| author_facet | Kim Nguyen Doan Alexander Grevel Christoph U. Mårtensson Lars Ellenrieder Nicolas Thornton Lena-Sophie Wenz Łukasz Opaliński Bernard Guiard Nikolaus Pfanner Thomas Becker |
| author_sort | Kim Nguyen Doan |
| collection | DOAJ |
| description | Summary: The mitochondrial outer membrane contains integral proteins with α-helical membrane anchors or a transmembrane β-barrel. The translocase of the outer membrane (TOM) cooperates with the sorting and assembly machinery (SAM) in the import of β-barrel proteins, whereas the mitochondrial import (MIM) complex inserts precursors of multi-spanning α-helical proteins. Single-spanning proteins constitute more than half of the integral outer membrane proteins; however, their biogenesis is poorly understood. We report that the yeast MIM complex promotes the insertion of proteins with N-terminal (signal-anchored) or C-terminal (tail-anchored) membrane anchors. The MIM complex exists in three dynamic populations. MIM interacts with TOM to accept precursor proteins from the receptor Tom70. Free MIM complexes insert single-spanning proteins that are imported in a Tom70-independent manner. Finally, coupling of MIM and SAM promotes early assembly steps of TOM subunits. We conclude that the MIM complex is a major and versatile protein translocase of the mitochondrial outer membrane. : Doan et al. report that the mitochondrial import (MIM) complex constitutes the major import site for single-spanning and multi-spanning outer membrane proteins. MIM exists in three forms and dynamically cooperates with outer membrane protein translocases to import different types of precursor proteins. Keywords: MIM complex, mitochondria, outer membrane, protein assembly, protein sorting, protein translocase, SAM complex, TOM complex |
| first_indexed | 2024-04-13T04:04:17Z |
| format | Article |
| id | doaj.art-372cd7f158e048d6b4e2bc4a61552a3a |
| institution | Directory Open Access Journal |
| issn | 2211-1247 |
| language | English |
| last_indexed | 2024-04-13T04:04:17Z |
| publishDate | 2020-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Cell Reports |
| spelling | doaj.art-372cd7f158e048d6b4e2bc4a61552a3a2022-12-22T03:03:21ZengElsevierCell Reports2211-12472020-04-01314The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane ProteinsKim Nguyen Doan0Alexander Grevel1Christoph U. Mårtensson2Lars Ellenrieder3Nicolas Thornton4Lena-Sophie Wenz5Łukasz Opaliński6Bernard Guiard7Nikolaus Pfanner8Thomas Becker9Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, GermanyInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, GermanyInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, GermanyInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, GermanyInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, GermanyInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, GermanyInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, GermanyCentre de Génétique Moléculaire, CNRS, 91190 Gif-sur-Yvette, FranceInstitute 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; Corresponding authorInstitute 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; Corresponding authorSummary: The mitochondrial outer membrane contains integral proteins with α-helical membrane anchors or a transmembrane β-barrel. The translocase of the outer membrane (TOM) cooperates with the sorting and assembly machinery (SAM) in the import of β-barrel proteins, whereas the mitochondrial import (MIM) complex inserts precursors of multi-spanning α-helical proteins. Single-spanning proteins constitute more than half of the integral outer membrane proteins; however, their biogenesis is poorly understood. We report that the yeast MIM complex promotes the insertion of proteins with N-terminal (signal-anchored) or C-terminal (tail-anchored) membrane anchors. The MIM complex exists in three dynamic populations. MIM interacts with TOM to accept precursor proteins from the receptor Tom70. Free MIM complexes insert single-spanning proteins that are imported in a Tom70-independent manner. Finally, coupling of MIM and SAM promotes early assembly steps of TOM subunits. We conclude that the MIM complex is a major and versatile protein translocase of the mitochondrial outer membrane. : Doan et al. report that the mitochondrial import (MIM) complex constitutes the major import site for single-spanning and multi-spanning outer membrane proteins. MIM exists in three forms and dynamically cooperates with outer membrane protein translocases to import different types of precursor proteins. Keywords: MIM complex, mitochondria, outer membrane, protein assembly, protein sorting, protein translocase, SAM complex, TOM complexhttp://www.sciencedirect.com/science/article/pii/S2211124720305167 |
| spellingShingle | Kim Nguyen Doan Alexander Grevel Christoph U. Mårtensson Lars Ellenrieder Nicolas Thornton Lena-Sophie Wenz Łukasz Opaliński Bernard Guiard Nikolaus Pfanner Thomas Becker The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins Cell Reports |
| title | The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins |
| title_full | The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins |
| title_fullStr | The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins |
| title_full_unstemmed | The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins |
| title_short | The Mitochondrial Import Complex MIM Functions as Main Translocase for α-Helical Outer Membrane Proteins |
| title_sort | mitochondrial import complex mim functions as main translocase for α helical outer membrane proteins |
| url | http://www.sciencedirect.com/science/article/pii/S2211124720305167 |
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