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MITRAC links mitochondrial protein translocation to respiratory-chain assembly and translational regulation.
- Source :
-
Cell [Cell] 2012 Dec 21; Vol. 151 (7), pp. 1528-41. - Publication Year :
- 2012
-
Abstract
- Mitochondrial respiratory-chain complexes assemble from subunits of dual genetic origin assisted by specialized assembly factors. Whereas core subunits are translated on mitochondrial ribosomes, others are imported after cytosolic translation. How imported subunits are ushered to assembly intermediates containing mitochondria-encoded subunits is unresolved. Here, we report a comprehensive dissection of early cytochrome c oxidase assembly intermediates containing proteins required for normal mitochondrial translation and reveal assembly factors promoting biogenesis of human respiratory-chain complexes. We find that TIM21, a subunit of the inner-membrane presequence translocase, is also present in the major assembly intermediates containing newly mitochondria-synthesized and imported respiratory-chain subunits, which we term MITRAC complexes. Human TIM21 is dispensable for protein import but required for integration of early-assembling, presequence-containing subunits into respiratory-chain intermediates. We establish an unexpected molecular link between the TIM23 transport machinery and assembly of respiratory-chain complexes that regulate mitochondrial protein synthesis in response to their assembly state.<br /> (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Subjects :
- Cyclooxygenase 1 genetics
Cyclooxygenase 1 metabolism
Cytosol metabolism
Humans
Membrane Proteins chemistry
Membrane Transport Proteins chemistry
Mitochondria chemistry
Mitochondria genetics
Mitochondrial Precursor Protein Import Complex Proteins
Mitochondrial Proteins chemistry
Protein Biosynthesis
Electron Transport Complex IV metabolism
Membrane Proteins metabolism
Membrane Transport Proteins metabolism
Mitochondria metabolism
Mitochondrial Membrane Transport Proteins metabolism
Mitochondrial Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1097-4172
- Volume :
- 151
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Cell
- Publication Type :
- Academic Journal
- Accession number :
- 23260140
- Full Text :
- https://doi.org/10.1016/j.cell.2012.11.053