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James Whelan - One of the best experts on this subject based on the ideXlab platform.
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MPIC: A Mitochondrial Protein Import Components Database for Plant and Non-Plant Species
Plant & cell physiology, 2014Co-Authors: Monika W. Murcha, Reena Narsai, James Devenish, Szymon Kubiszewski-jakubiak, James WhelanAbstract:In the 2 billion years since the endosymbiotic event that gave rise to mitochondria, variations in Mitochondrial Protein import have evolved across different species. With the genomes of an increasing number of plant species sequenced, it is possible to gain novel insights into Mitochondrial Protein import pathways. We have generated the Mitochondrial Protein Import Components (MPIC) Database (DB; http://www.plantenergy.uwa.edu.au/applications/mpic) providing searchable information on the Protein import apparatus of plant and non-plant mitochondria. An in silico analysis was carried out, comparing the Mitochondrial Protein import apparatus from 24 species representing various lineages from Saccharomyces cerevisiae (yeast) and algae to Homo sapiens (human) and higher plants, including Arabidopsis thaliana (Arabidopsis), Oryza sativa (rice) and other more recently sequenced plant species. Each of these species was extensively searched and manually assembled for analysis in the MPIC DB. The database presents an interactive diagram in a user-friendly manner, allowing users to select their import component of interest. The MPIC DB presents an extensive resource facilitating detailed investigation of the Mitochondrial Protein import machinery and allowing patterns of conservation and divergence to be recognized that would otherwise have been missed. To demonstrate the usefulness of the MPIC DB, we present a comparative analysis of the Mitochondrial Protein import machinery in plants and non-plant species, revealing plant-specific features that have evolved.
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Mitochondrial Protein Import: Convergent Solutions for Receptor Structure
Current Biology, 2006Co-Authors: Ryan Lister, James WhelanAbstract:Complex machinery has evolved to recognise and import nuclear-encoded Proteins into mitochondria. Recent work now shows that the plant Tom20 Mitochondrial Protein import receptor has a similar tertiary structure to animal Tom20, although the Proteins are evolutionarily distinct, representing an elegant example of convergent evolution.
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The Mitochondrial Protein Import Machinery of Plants (MPIMP) database.
Nucleic acids research, 2003Co-Authors: Ryan Lister, Monika W. Murcha, James WhelanAbstract:The Mitochondrial Protein Import Machinery of Plants database (MPIMP) is an Internet-accessible database containing detailed information on the Protein import apparatus of plant mitochondria. The Arabidopsis genome was searched for com- ponents of the Mitochondrial Protein import apparatus using components from the well- characterized model system of Saccharomyces cerevisiae. Twenty six homologues of 34 compo- nents could be found, encompassing the essential components for the general and carrier import pathways. The database is available through the Internet at http://millar3.biochem.uwa.edu.au/~lister/ index.html.
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Plant Mitochondrial Protein import : mechanisms and control
Functional Plant Biology, 1999Co-Authors: James WhelanAbstract:The characterisation of components of the plant Mitochondrial import apparatus along with the availability of over one hundred nuclear-encoded Mitochondrial Proteins allows the study of plant Mitochondrial Protein import in homologous systems. From these studies it has emerged that although similarities in the import process exist with other organisms, significance differences exist, such as receptor structure, location of processing peptidase and targeting signals. These differences mean that previous studies carried out in heterologous systems must be re-evaluated. Further studies into Protein import in plants need to be directed at understanding the mechanism of import and how this process may be controlled. In this review the latter points will be dealt with in terms of summarising our current knowledge and possible future directions.
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Mitochondrial Protein import in plants – Signals, Sorting, Targeting, Processing and Regulation
Plant Molecular Biology, 1998Co-Authors: Elzbieta Glaser, Sara Sjöling, Marcel Tanudji, James WhelanAbstract:Mitochondrial biogenesis requires a coordinated expression of both the nuclear and the organellar genomes and specific intracellular Protein trafficking, processing and assembly machinery. Most Mitochondrial Proteins are synthesised as precursor Proteins containing an N-terminal extension which functions as a targeting signal, which is proteolytically cleaved off after import into mitochondria. We review our present knowledge on components and mechanisms involved in the Mitochondrial Protein import process in plants. This encompasses properties of targeting peptides, sorting of precursor Proteins between mitochondria and chloroplasts, signal recognition, mechanism of translocation across the Mitochondrial membranes and the role of cytosolic and organellar molecular chaperones in this process. The Mitochondrial Protein processing in plants is catalysed by the Mitochondrial processing peptidase (MPP), which in contrast to other sources, is integrated into the bc_1 complex of the respiratory chain. This is the most studied component of the plant import machinery characterised to date. What are the biochemical consequences of the integration of the MPP into an oligomeric Protein complex and how are several hundred presequences of precursor Proteins with no sequence similarities and no consensus for cleavage, specifically cleaved off by MPP? Finally we will address the emerging area of the control of Protein import into mitochondria.
J. Mark Cock - One of the best experts on this subject based on the ideXlab platform.
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In Silico Survey of the Mitochondrial Protein Uptake and Maturation Systems in the Brown Alga Ectocarpus siliculosus
PLoS ONE, 2011Co-Authors: Ludovic Delage, Lieven Sterck, Catherine Leblanc, Pi Nyvall Collén, Bernhard Gschloessl, Marie-pierre Oudot, Julie Poulain, Jean-marc Aury, J. Mark CockAbstract:The acquisition of mitochondria was a key event in eukaryote evolution. The aim of this study was to identify homologues of the components of the Mitochondrial Protein import machinery in the brown alga Ectocarpus and to use this information to investigate the evolutionary history of this fundamental cellular process. Detailed searches were carried out both for components of the Protein import system and for related peptidases. Comparative and phylogenetic analyses were used to investigate the evolution of Mitochondrial Proteins during eukaryote diversification. Key observations include phylogenetic evidence for very ancient origins for many Protein import components (Tim21, Tim50, for example) and indications of differences between the outer membrane receptors that recognize the Mitochondrial targeting signals, suggesting replacement, rearrangement and/or emergence of new components across the major eukaryotic lineages. Overall, the Mitochondrial Protein import components analysed in this study confirmed a high level of conservation during evolution, indicating that most are derived from very ancient, ancestral Proteins. Several of the Protein import components identified in Ectocarpus, such as Tim21, Tim50 and metaxin, have also been found in other stramenopiles and this study suggests an early origin during the evolution of the eukaryotes.
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In Silico Survey of the Mitochondrial Protein Uptake and Maturation Systems in the Brown Alga Ectocarpus siliculosus
PLoS ONE, 2011Co-Authors: Ludovic Delage, Lieven Sterck, Catherine Leblanc, Pi Nyvall Collén, Bernhard Gschloessl, Marie-pierre Oudot, Julie Poulain, Jean-marc Aury, J. Mark CockAbstract:The acquisition of mitochondria was a key event in eukaryote evolution. The aim of this study was to identify homologues of the components of the Mitochondrial Protein import machinery in the brown alga Ectocarpus and to use this information to investigate the evolutionary history of this fundamental cellular process. Detailed searches were carried out both for components of the Protein import system and for related peptidases. Comparative and phylogenetic analyses were used to investigate the evolution of Mitochondrial Proteins during eukaryote diversification. Key observations include phylogenetic evidence for very ancient origins for many Protein import components (Tim21, Tim50, for example) and indications of differences between the outer membrane receptors that recognize the Mitochondrial targeting signals, suggesting replacement, rearrangement and/or emergence of new components across the major eukaryotic lineages. Overall, the Mitochondrial Protein import components analysed in this study confirmed a high level of conservation during evolution, indicating that most are derived from very ancient, ancestral Proteins. Several of the Protein import components identified in Ectocarpus, such as Tim21, Tim50 and metaxin, have also been found in other stramenopiles and this study suggests an early origin during the evolution of the eukaryotes. Citation: Delage L, Leblanc C, Nyvall Collén P, Gschloessl B, Oudot M-P, et al. (2011) In Silico Survey of the Mitochondrial Protein Uptake and Maturation Systems in the Brown Alga Ectocarpus siliculosus. PLoS ONE 6(5): e19540.
Toshiya Endo - One of the best experts on this subject based on the ideXlab platform.
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Multifaceted roles of porin in Mitochondrial Protein and lipid transport.
Biochemical Society transactions, 2019Co-Authors: Toshiya Endo, Haruka SakaueAbstract:Mitochondria are essential eukaryotic organelles responsible for primary cellular energy production. Biogenesis, maintenance, and functions of mitochondria require correct assembly of resident Proteins and lipids, which require their transport into and within mitochondria. Mitochondrial normal functions also require an exchange of small metabolites between the cytosol and mitochondria, which is primarily mediated by a metabolite channel of the outer membrane (OM) called porin or voltage-dependent anion channel. Here, we describe recently revealed novel roles of porin in the Mitochondrial Protein and lipid transport. First, porin regulates the formation of the Mitochondrial Protein import gate in the OM, the translocase of the outer membrane (TOM) complex, and its dynamic exchange between the major form of a trimer and the minor form of a dimer. The TOM complex dimer lacks a core subunit Tom22 and mediates the import of a subset of Mitochondrial Proteins while the TOM complex trimer facilitates the import of most other Mitochondrial Proteins. Second, porin interacts with both a translocating inner membrane (IM) Protein like a carrier Protein accumulated at the small TIM chaperones in the intermembrane space and the TIM22 complex, a downstream translocator in the IM for the carrier Protein import. Porin thereby facilitates the efficient transfer of carrier Proteins to the IM during their import. Third, porin facilitates the transfer of lipids between the OM and IM and promotes a back-up pathway for the cardiolipin synthesis in mitochondria. Thus, porin has roles more than the metabolite transport in the Protein and lipid transport into and within mitochondria, which is likely conserved from yeast to human.
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Structural insight into the Mitochondrial Protein import system.
Biochimica et biophysica acta, 2010Co-Authors: Toshiya Endo, Koji Yamano, Shin KawanoAbstract:Mitochondrial functions rely on precise and efficient transport of 1000–1500 different Mitochondrial Proteins from the cytosol to appropriate Mitochondrial subcompartments. Those Mitochondrial Protein transport processes are mediated by the dedicated Mitochondrial Protein import system comprised of translocators in the outer and inner Mitochondrial membranes and soluble factors in the cytosol, intermembrane space, and matrix. In the last decade, high-resolution structures of many of the components of the Mitochondrial Protein import machineries have become available, which has significantly advanced our understanding of the molecular mechanisms of Mitochondrial Protein transport. Here we review the currently available high-resolution structures of the components of the Mitochondrial Protein import machineries that afford structural and mechanistic insight into how the Mitochondrial import system works. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.
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Multiple pathways for Mitochondrial Protein traffic
Biological chemistry, 2009Co-Authors: Toshiya Endo, Koji YamanoAbstract:Mitochondria are two-membrane bounded organelles consisting of 1000-2000 different Proteins, most of which are synthesized in the cytosol and subsequently imported into mitochondria. The imported Proteins are further sorted to one of the four compartments, the outer membrane, intermembrane space, inner membrane, and matrix, mostly following one of the five major pathways. Mitochondrial Protein import and sorting are mediated by the translocator complexes in the membranes and chaperones in the aqueous compartments operating along the import pathways. Here, we summarize the expanding knowledge on the roles of translocators, chaperones, and related components in the multiple pathways for Mitochondrial Protein trafficking.
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tim23 tim50 pair coordinates functions of translocators and motor Proteins in Mitochondrial Protein import
Journal of Cell Biology, 2009Co-Authors: Yasushi Tamura, Koji Yamano, Yoshihiro Harada, Takuya Shiota, Kazuaki Watanabe, Mihoko Yokota, Hayashi Yamamoto, Hiromi Sesaki, Toshiya EndoAbstract:Mitochondrial Protein traffic requires coordinated operation of Protein translocator complexes in the Mitochondrial membrane. The TIM23 complex translocates and inserts Proteins into the Mitochondrial inner membrane. Here we analyze the intermembrane space (IMS) domains of Tim23 and Tim50, which are essential subunits of the TIM23 complex, in these functions. We find that interactions of Tim23 and Tim50 in the IMS facilitate transfer of precursor Proteins from the TOM40 complex, a general Protein translocator in the outer membrane, to the TIM23 complex. Tim23–Tim50 interactions also facilitate a late step of Protein translocation across the inner membrane by promoting motor functions of Mitochondrial Hsp70 in the matrix. Therefore, the Tim23–Tim50 pair coordinates the actions of the TOM40 and TIM23 complexes together with motor Proteins for Mitochondrial Protein import.
Ludovic Delage - One of the best experts on this subject based on the ideXlab platform.
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In Silico Survey of the Mitochondrial Protein Uptake and Maturation Systems in the Brown Alga Ectocarpus siliculosus
PLoS ONE, 2011Co-Authors: Ludovic Delage, Lieven Sterck, Catherine Leblanc, Pi Nyvall Collén, Bernhard Gschloessl, Marie-pierre Oudot, Julie Poulain, Jean-marc Aury, J. Mark CockAbstract:The acquisition of mitochondria was a key event in eukaryote evolution. The aim of this study was to identify homologues of the components of the Mitochondrial Protein import machinery in the brown alga Ectocarpus and to use this information to investigate the evolutionary history of this fundamental cellular process. Detailed searches were carried out both for components of the Protein import system and for related peptidases. Comparative and phylogenetic analyses were used to investigate the evolution of Mitochondrial Proteins during eukaryote diversification. Key observations include phylogenetic evidence for very ancient origins for many Protein import components (Tim21, Tim50, for example) and indications of differences between the outer membrane receptors that recognize the Mitochondrial targeting signals, suggesting replacement, rearrangement and/or emergence of new components across the major eukaryotic lineages. Overall, the Mitochondrial Protein import components analysed in this study confirmed a high level of conservation during evolution, indicating that most are derived from very ancient, ancestral Proteins. Several of the Protein import components identified in Ectocarpus, such as Tim21, Tim50 and metaxin, have also been found in other stramenopiles and this study suggests an early origin during the evolution of the eukaryotes.
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In Silico Survey of the Mitochondrial Protein Uptake and Maturation Systems in the Brown Alga Ectocarpus siliculosus
PLoS ONE, 2011Co-Authors: Ludovic Delage, Lieven Sterck, Catherine Leblanc, Pi Nyvall Collén, Bernhard Gschloessl, Marie-pierre Oudot, Julie Poulain, Jean-marc Aury, J. Mark CockAbstract:The acquisition of mitochondria was a key event in eukaryote evolution. The aim of this study was to identify homologues of the components of the Mitochondrial Protein import machinery in the brown alga Ectocarpus and to use this information to investigate the evolutionary history of this fundamental cellular process. Detailed searches were carried out both for components of the Protein import system and for related peptidases. Comparative and phylogenetic analyses were used to investigate the evolution of Mitochondrial Proteins during eukaryote diversification. Key observations include phylogenetic evidence for very ancient origins for many Protein import components (Tim21, Tim50, for example) and indications of differences between the outer membrane receptors that recognize the Mitochondrial targeting signals, suggesting replacement, rearrangement and/or emergence of new components across the major eukaryotic lineages. Overall, the Mitochondrial Protein import components analysed in this study confirmed a high level of conservation during evolution, indicating that most are derived from very ancient, ancestral Proteins. Several of the Protein import components identified in Ectocarpus, such as Tim21, Tim50 and metaxin, have also been found in other stramenopiles and this study suggests an early origin during the evolution of the eukaryotes. Citation: Delage L, Leblanc C, Nyvall Collén P, Gschloessl B, Oudot M-P, et al. (2011) In Silico Survey of the Mitochondrial Protein Uptake and Maturation Systems in the Brown Alga Ectocarpus siliculosus. PLoS ONE 6(5): e19540.
Nektarios Tavernarakis - One of the best experts on this subject based on the ideXlab platform.
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Oxidative stress and Mitochondrial Protein quality control in aging
Journal of proteomics, 2013Co-Authors: Eirini Lionaki, Nektarios TavernarakisAbstract:Mitochondrial Protein quality control incorporates an elaborate network of chaperones and proteases that survey the organelle for misfolded or unfolded Proteins and toxic aggregates. Repair of misfolded or aggregated Protein and proteolytic removal of irreversibly damaged Proteins are carried out by the Mitochondrial Protein quality control system. Initial maturation and folding of the nuclear or Mitochondrial-encoded Mitochondrial Proteins are mediated by processing peptidases and chaperones that interact with the Protein translocation machinery. Mitochondrial Proteins are subjected to cumulative oxidative damage. Thus, impairment of quality control processes may cause Mitochondrial dysfunction. Aging has been associated with a marked decline in the effectiveness of Mitochondrial Protein quality control. Here, we present an overview of the chaperones and proteases involved in the initial folding and maturation of new, incoming precursor molecules, and the subsequent repair and removal of oxidized aggregated Proteins. In addition, we highlight the link between Mitochondrial Protein quality control mechanisms and the aging process. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine.