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Tarasenko TA, Koulintchenko MV. Heterogeneity of the Mitochondrial Population in Cells of Plants and Other Organisms. Mol Biol 2022. [DOI: 10.1134/s0026893322020157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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2
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Borovik OA, Grabelnych OI. Mitochondrial alternative cyanide-resistant oxidase is involved in an increase of heat stress tolerance in spring wheat. JOURNAL OF PLANT PHYSIOLOGY 2018; 231:310-317. [PMID: 30368229 DOI: 10.1016/j.jplph.2018.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 10/04/2018] [Accepted: 10/07/2018] [Indexed: 06/08/2023]
Abstract
The aim of this study was to determine the influence of different heat treatments on the alternative cyanide-resistant oxidase (AOX) capacity and establish a relation between the heat stress tolerance of spring wheat (Triticum aestivum L.), content of water-soluble carbohydrates in leaves and the alternative respiratory pathway (AP) capacity. We identified a positive relation between these studied parameters. Heat exposure at 39 °C for 24 h increased the heat stress tolerance of seedlings, content of water-soluble carbohydrates and AOX capacity, and the AOX capacity was also high after the subsequent influence of heat shock (50 °C for 3 h). The increased AOX capacity correlated with an increased level of water-soluble carbohydrates in leaves. The content of the AOX protein increased after heat exposure at 39 °C (for 3 h and 24 h) and after the subsequent influence of heat shock (50 °C for 1 and 3 h) at 39 °C for 24 h. We also detected that the content of AOX protein isoforms depends on the duration and intensity of heat treatment. It was concluded that AOX plays an important role in the acclimation of plants to high temperatures.
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Affiliation(s)
- Olga A Borovik
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch, Russian Academy of Sciences, 132 Lermontov Str., 664033, Irkutsk, Russia.
| | - Olga I Grabelnych
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch, Russian Academy of Sciences, 132 Lermontov Str., 664033, Irkutsk, Russia
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3
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Murcha MW, Kmiec B, Kubiszewski-Jakubiak S, Teixeira PF, Glaser E, Whelan J. Protein import into plant mitochondria: signals, machinery, processing, and regulation. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6301-35. [PMID: 25324401 DOI: 10.1093/jxb/eru399] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The majority of more than 1000 proteins present in mitochondria are imported from nuclear-encoded, cytosolically synthesized precursor proteins. This impressive feat of transport and sorting is achieved by the combined action of targeting signals on mitochondrial proteins and the mitochondrial protein import apparatus. The mitochondrial protein import apparatus is composed of a number of multi-subunit protein complexes that recognize, translocate, and assemble mitochondrial proteins into functional complexes. While the core subunits involved in mitochondrial protein import are well conserved across wide phylogenetic gaps, the accessory subunits of these complexes differ in identity and/or function when plants are compared with Saccharomyces cerevisiae (yeast), the model system for mitochondrial protein import. These differences include distinct protein import receptors in plants, different mechanistic operation of the intermembrane protein import system, the location and activity of peptidases, the function of inner-membrane translocases in linking the outer and inner membrane, and the association/regulation of mitochondrial protein import complexes with components of the respiratory chain. Additionally, plant mitochondria share proteins with plastids, i.e. dual-targeted proteins. Also, the developmental and cell-specific nature of mitochondrial biogenesis is an aspect not observed in single-celled systems that is readily apparent in studies in plants. This means that plants provide a valuable model system to study the various regulatory processes associated with protein import and mitochondrial biogenesis.
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Affiliation(s)
- Monika W Murcha
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Beata Kmiec
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, SE-10691 Stockholm, Sweden
| | - Szymon Kubiszewski-Jakubiak
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Pedro F Teixeira
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, SE-10691 Stockholm, Sweden
| | - Elzbieta Glaser
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, SE-10691 Stockholm, Sweden
| | - James Whelan
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria, 3086, Australia
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Murcha MW, Kubiszewski-Jakubiak S, Wang Y, Whelan J. Evidence for interactions between the mitochondrial import apparatus and respiratory chain complexes via Tim21-like proteins in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2014; 5:82. [PMID: 24653731 PMCID: PMC3949100 DOI: 10.3389/fpls.2014.00082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 02/21/2014] [Indexed: 05/06/2023]
Abstract
The mitochondrial import machinery and the respiratory chain complexes of the inner membrane are highly interdependent for the efficient import and assembly of nuclear encoded respiratory chain components and for the generation of a proton motive force essential for protein translocation into or across the inner membrane. In plant and non-plant systems functional, physical, and evolutionary associations have been observed between proteins of the respiratory chain and protein import apparatus. Here we identify two novel Tim21-like proteins encoded by At2g40800 and At3g56430 that are imported into the mitochondrial inner membrane. We propose that Tim21-like proteins may associate with respiratory chain Complex I, III, in addition to the TIM17:23 translocase of the inner membrane. These results are discussed further with regards to the regulation of mitochondrial activity and biogenesis.
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Affiliation(s)
- Monika W. Murcha
- ARC Centre of Excellence in Plant Energy Biology, The University of Western AustraliaPerth, WA, Australia
- *Correspondence: Monika W. Murcha, ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, MCS Building M316, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia e-mail:
| | | | - Yan Wang
- ARC Centre of Excellence in Plant Energy Biology, The University of Western AustraliaPerth, WA, Australia
| | - James Whelan
- Department of Botany, ARC Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe UniversityBundoora, VIC, Australia
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Lee S, Lee DW, Yoo YJ, Duncan O, Oh YJ, Lee YJ, Lee G, Whelan J, Hwang I. Mitochondrial targeting of the Arabidopsis F1-ATPase γ-subunit via multiple compensatory and synergistic presequence motifs. THE PLANT CELL 2012; 24:5037-57. [PMID: 23250447 PMCID: PMC3556974 DOI: 10.1105/tpc.112.105361] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The majority of mitochondrial proteins are encoded in the nuclear genome and imported into mitochondria posttranslationally from the cytosol. An N-terminal presequence functions as the signal for the import of mitochondrial proteins. However, the functional information in the presequence remains elusive. This study reports the identification of critical sequence motifs from the presequence of Arabidopsis thaliana F1-ATPase γ-subunit (pFAγ). pFAγ was divided into six 10-amino acid segments, designated P1 to P6 from the N to the C terminus, each of which was further divided into two 5-amino acid subdivisions. These P segments and their subdivisions were substituted with Ala residues and fused to green fluorescent protein (GFP). Protoplast targeting experiments using these GFP constructs revealed that pFAγ contains several functional sequence motifs that are dispersed throughout the presequence. The sequence motifs DQEEG (P4a) and VVRNR (P5b) were involved in translocation across the mitochondrial membranes. The sequence motifs IAARP (P2b) and IAAIR (P3a) participated in binding to mitochondria. The sequence motifs RLLPS (P2a) and SISTQ (P5a) assisted in pulling proteins into the matrix, and the sequence motif IAARP (P2b) functioned in Tom20-dependent import. In addition, these sequence motifs exhibit complex relationships, including synergistic functions. Thus, multiple sequence motifs dispersed throughout the presequence are proposed to function cooperatively during protein import into mitochondria.
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Affiliation(s)
- Sumin Lee
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Yun-Joo Yoo
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Owen Duncan
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley WA 6009, Western Australia, Australia
| | - Young Jun Oh
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Yong Jik Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Goeun Lee
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - James Whelan
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley WA 6009, Western Australia, Australia
| | - Inhwan Hwang
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Korea
- Address correspondence to
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Duncan O, Murcha MW, Whelan J. Unique components of the plant mitochondrial protein import apparatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:304-13. [PMID: 22406071 DOI: 10.1016/j.bbamcr.2012.02.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/21/2012] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
Abstract
The basic mitochondrial protein import apparatus was established in the earliest eukaryotes. Over the subsequent course of evolution and the divergence of the plant, animal and fungal lineages, this basic import apparatus has been modified and expanded in order to meet the specific needs of protein import in each kingdom. In the plant kingdom, the arrival of the plastid complicated the process of protein trafficking and is thought to have given rise to the evolution of a number of unique components that allow specific and efficient targeting of mitochondrial proteins from their site of synthesis in the cytosol, to their final location in the organelle. This includes the evolution of two unique outer membrane import receptors, plant Translocase of outer membrane 20 kDa subunit (TOM20) and Outer membrane protein of 64 kDa (OM64), the loss of a receptor domain from an ancestral import component, Translocase of outer membrane 22 kDa subunit (TOM22), evolution of unique features in the disulfide relay system of the inter membrane space, and the addition of an extra membrane spanning domain to another ancestral component of the inner membrane, Translocase of inner membrane 17 kDa subunit (TIM17). Notably, many of these components are encoded by multi-gene families and exhibit differential sub-cellular localisation and functional specialisation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, Bayliss Building M316, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
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Kriechbaumer V, von Löffelholz O, Abell BM. Chaperone receptors: guiding proteins to intracellular compartments. PROTOPLASMA 2012; 249:21-30. [PMID: 21461941 DOI: 10.1007/s00709-011-0270-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 03/02/2011] [Indexed: 05/04/2023]
Abstract
Despite mitochondria and chloroplasts having their own genome, 99% of mitochondrial proteins (Rehling et al., Nat Rev Mol Cell Biol 5:519-530, 2004) and more than 95% of chloroplast proteins (Soll, Curr Opin Plant Biol 5:529-535, 2002) are encoded by nuclear DNA, synthesised in the cytosol and imported post-translationally. Protein targeting to these organelles depends on cytosolic targeting factors, which bind to the precursor, and then interact with membrane receptors to deliver the precursor into a translocase. The molecular chaperones Hsp70 and Hsp90 have been widely implicated in protein targeting to mitochondria and chloroplasts, and receptors capable of recognising these chaperones have been identified at the surface of both these organelles (Schlegel et al., Mol Biol Evol 24:2763-2774, 2007). The role of these chaperone receptors is not fully understood, but they have been shown to increase the efficiency of protein targeting (Young et al., Cell 112:41-50, 2003; Qbadou et al., EMBO J 25:1836-1847, 2006). Whether these receptors contribute to the specificity of targeting is less clear. A class of chaperone receptors bearing tetratricopeptide repeat domains is able to specifically bind the highly conserved C terminus of Hsp70 and/or Hsp90. Interestingly, at least of one these chaperone receptors can be found on each organelle (Schlegel et al., Mol Biol Evol 24:2763-2774, 2007), which suggests a universal role in protein targeting for these chaperone receptors. This review will investigate the role that chaperone receptors play in targeting efficiency and specificity, as well as examining recent in silico approaches to find novel chaperone receptors.
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Devaux F, Lelandais G, Garcia M, Goussard S, Jacq C. Posttranscriptional control of mitochondrial biogenesis: Spatio-temporal regulation of the protein import process. FEBS Lett 2010; 584:4273-9. [DOI: 10.1016/j.febslet.2010.09.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 09/10/2010] [Accepted: 09/18/2010] [Indexed: 11/30/2022]
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Rödiger A, Baudisch B, Klösgen RB. Simultaneous isolation of intact mitochondria and chloroplasts from a single pulping of plant tissue. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:620-4. [PMID: 20045215 DOI: 10.1016/j.jplph.2009.11.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 05/08/2023]
Abstract
Isolated organelles are suitable tools for the investigation of organelle function. However, if the properties of different organelles are to be compared, analysis is generally impeded by the fact that the organelles are isolated independently from each other from different specimens, different tissues or even different plants, i.e. the organelles have been exposed to different conditions during growth and development. Here we describe a method to isolate intact chloroplasts and mitochondria simultaneously from a single pulping of pea leaves, which results in organelles with an essentially identical physiological background. The functionality of the isolated chloroplasts and mitochondria is demonstrated by protein transport experiments, which yield results identical to those obtained with independently isolated organelles. With slight modifications, the method is also successfully applied to organelles from potato and spinach, which implies that it may be generally applicable to organelles from many different species.
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Affiliation(s)
- Anja Rödiger
- Institut für Biologie - Pflanzenphysiologie, Martin-Luther-Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany
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Nilsson Cederholm S, Bäckman HG, Pesaresi P, Leister D, Glaser E. Deletion of an organellar peptidasome PreP affects early development in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2009; 71:497-508. [PMID: 19701724 DOI: 10.1007/s11103-009-9534-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 08/02/2009] [Indexed: 05/28/2023]
Abstract
A novel peptidasome PreP is responsible for degradation of targeting peptides and other unstructured peptides in mitochondria and chloroplasts. Arabidopsis thaliana contains two PreP isoforms, AtPreP1, and AtPreP2. Here we have characterized single and double prep knockout mutants. Immunoblot analysis of atprep1 and atprep2 mutants showed that both isoforms are expressed in all tissues with the highest expression in flowers and siliques; additionally, AtPreP1 accumulated to a much higher level in comparison to AtPreP2. The atprep2 mutant behaved like wild type, whereas deletion of AtPreP1 resulted in slightly pale-green seedlings. Analysis of the atprep1 atprep2 double mutant revealed a chlorotic phenotype in true leaves with diminished chlorophyll a and b content, but unchanged Chl a/b ratio indicating a proportional decrease of both PSI and PSII complexes. Mitochondrial respiratory rates (state 3) were lower and the mitochondria were partially uncoupled. EM pictures on cross sections of the first true leaves showed aberrant chloroplasts, including less grana stacking and less starch granules. Mitochondria with extremely variable size could also be observed. At later developmental stages the plants appeared almost normal. However, all through the development there was a statistically significant decrease of approximately 40% in the accumulated biomass in the double mutant plants in comparison to wild type. In mitochondria, deletion of AtPreP was not compensated by activation of any peptidolytic activity, whereas chloroplast membranes contained a minor peptidolytic activity not related to AtPreP. In summary, the AtPreP peptidasome is required for efficient plant growth and organelle function particularly during early development.
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Millar AH, Small ID, Day DA, Whelan J. Mitochondrial biogenesis and function in Arabidopsis. THE ARABIDOPSIS BOOK 2008; 6:e0111. [PMID: 22303236 DOI: 10.1199/tab.0105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mitochondria represent the powerhouse of cells through their synthesis of ATP. However, understanding the role of mitochondria in the growth and development of plants will rely on a much deeper appreciation of the complexity of this organelle. Arabidopsis research has provided clear identification of mitochondrial components, allowed wide-scale analysis of gene expression, and has aided reverse genetic manipulation to test the impact of mitochondrial component loss on plant function. Forward genetics in Arabidopsis has identified mitochondrial involvement in mutations with notable impacts on plant metabolism, growth and development. Here we consider the evidence for components involved in mitochondria biogenesis, metabolism and signalling to the nucleus.
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Lister R, Carrie C, Duncan O, Ho LHM, Howell KA, Murcha MW, Whelan J. Functional definition of outer membrane proteins involved in preprotein import into mitochondria. THE PLANT CELL 2007; 19:3739-59. [PMID: 17981999 PMCID: PMC2174869 DOI: 10.1105/tpc.107.050534] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The role of plant mitochondrial outer membrane proteins in the process of preprotein import was investigated, as some of the principal components characterized in yeast have been shown to be absent or evolutionarily distinct in plants. Three outer membrane proteins of Arabidopsis thaliana mitochondria were studied: TOM20 (translocase of the outer mitochondrial membrane), METAXIN, and mtOM64 (outer mitochondrial membrane protein of 64 kD). A single functional Arabidopsis TOM20 gene is sufficient to produce a normal multisubunit translocase of the outer membrane complex. Simultaneous inactivation of two of the three TOM20 genes changed the rate of import for some precursor proteins, revealing limited isoform subfunctionalization. Inactivation of all three TOM20 genes resulted in severely reduced rates of import for some but not all precursor proteins. The outer membrane protein METAXIN was characterized to play a role in the import of mitochondrial precursor proteins and likely plays a role in the assembly of beta-barrel proteins into the outer membrane. An outer mitochondrial membrane protein of 64 kD (mtOM64) with high sequence similarity to a chloroplast import receptor was shown to interact with a variety of precursor proteins. All three proteins have domains exposed to the cytosol and interacted with a variety of precursor proteins, as determined by pull-down and yeast two-hybrid interaction assays. Furthermore, inactivation of one resulted in protein abundance changes in the others, suggesting functional redundancy. Thus, it is proposed that all three components directly interact with precursor proteins to participate in early stages of mitochondrial protein import.
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Affiliation(s)
- Ryan Lister
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, Western Australia, Australia
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Howell KA, Cheng K, Murcha MW, Jenkin LE, Millar AH, Whelan J. Oxygen initiation of respiration and mitochondrial biogenesis in rice. J Biol Chem 2007; 282:15619-31. [PMID: 17383966 DOI: 10.1074/jbc.m609866200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rice growth under aerobic and anaerobic conditions allowed aspects of mitochondrial biogenesis to be identified as dependent on or independent of an oxygen signal. Analysis of transcripts encoding mitochondrial components found that a subset of these genes respond to oxygen (defined as aerobic), whereas others are relatively unaffected by oxygen availability. Mitochondria formed during growth in anaerobic conditions had reduced protein levels of tricarboxylic acid cycle components and cytochrome-containing complexes of the respiratory chain and repressed respiratory functionality. In general, the capacity of the general import pathway was found to be significantly lower in mitochondria isolated from tissue grown under anaerobic conditions, whereas the carrier import pathway capacity was not affected by changes in oxygen availability. Transcript levels of genes encoding components of the protein import apparatus were generally not affected by the absence of oxygen, and their protein abundance was severalfold higher in mitochondria isolated from anaerobically grown tissue. However, both transcript and protein abundances of the subunits of the mitochondrial processing peptidase, which in plants is integrated into the cytochrome bc(1) complex, were repressed under anaerobic conditions. Therefore, in this system, an increase in import capacity is correlated with an increase in the abundance of the cytochrome bc(1) complex, which is ultimately dependent on the presence of oxygen, providing a link between the respiratory chain and protein import apparatus.
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Affiliation(s)
- Katharine A Howell
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Perth, Western Australia 6009, Australia
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Howell KA, Millar AH, Whelan J. Ordered assembly of mitochondria during rice germination begins with pro-mitochondrial structures rich in components of the protein import apparatus. PLANT MOLECULAR BIOLOGY 2006; 60:201-23. [PMID: 16429260 DOI: 10.1007/s11103-005-3688-7] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 10/03/2005] [Indexed: 05/06/2023]
Abstract
Mitochondrial maturation during imbibition of rice embryos follows the transition of unstructured double membrane bound pro-mitochondria to the typical cristae-rich mitochondrial structures observed in mature plant cells. During the first 48 h following imbibition, an ordered increase in the abundance of transcripts encoding mitochondrial proteins was observed. Co-incident with these changes in transcript levels was dynamic and rapid changes in mitochondrial protein content and mitochondrial function. Proteins representing components of the mitochondrial protein import apparatus are strikingly abundant in dry seeds, and a functional import apparatus was shown to operate 2 h after imbibition. Interestingly, this import process was best driven by the oxidation of NADH from outside the mitochondrial inner membrane. In later developmental stages the capacity for matrix organic acid metabolism was evident, accompanied by the appearance of proteins for TCA cycle components, and coordination of electron transport chain assembly through components encoded in both mitochondrial and nuclear genomes. Together these events provide new insights into the understanding of mitochondrial maturation and the nature of pro-mitochondrial structures in plant cells.
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Affiliation(s)
- Katharine A Howell
- ARC Centre of Excellence in Plant Energy Biology, CMS Building M310, University of Western Australia, 35 Stirling Hwy, Perth, WA 6009, Australia
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Lister R, Hulett JM, Lithgow T, Whelan J. Protein import into mitochondria: origins and functions today (review). Mol Membr Biol 2005; 22:87-100. [PMID: 16092527 DOI: 10.1080/09687860500041247] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Mitochondria are organelles derived from alpha-proteobacteria over the course of one to two billion years. Mitochondria from the major eukaryotic lineages display some variation in functions and coding capacity but sequence analysis demonstrates them to be derived from a single common ancestral endosymbiont. The loss of assorted functions, the transfer of genes to the nucleus, and the acquisition of various 'eukaryotic' proteins have resulted in an organelle that contains approximately 1000 different proteins, with most of these proteins imported into the organelle across one or two membranes. A single translocase in the outer membrane and two translocases in the inner membrane mediate protein import. Comparative sequence analysis and functional complementation experiments suggest some components of the import pathways to be directly derived from the eubacterial endosymbiont's own proteins, and some to have arisen 'de novo' at the earliest stages of 'mitochondrification' of the endosymbiont. A third class of components appears lineage-specific, suggesting they were incorporated into the process of protein import long after mitochondria was established as an organelle and after the divergence of the various eukaryotic lineages. Protein sorting pathways inherited from the endosymbiont have been co-opted and play roles in intraorganelle protein sorting after import. The import apparatus of animals and fungi show significant similarity to one another, but vary considerably to the plant apparatus. Increasing complexity in the eukaryotic lineage, i.e., from single celled to multi-cellular life forms, has been accompanied by an expansion in genes encoding each component, resulting in small gene families encoding many components. The functional differences in these gene families remain to be elucidated, but point to a mosaic import apparatus that can be regulated by a variety of signals.
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Affiliation(s)
- Ryan Lister
- Plant Molecular Biology Group, School of Biomedical and Chemical Sciences, The University of Western Australia, Crawley, Western Australia, Australia
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Chew O, Whelan J. Just read the message: a model for sorting of proteins between mitochondria and chloroplasts. TRENDS IN PLANT SCIENCE 2004; 9:318-9. [PMID: 15231275 DOI: 10.1016/j.tplants.2004.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
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Rajjou L, Gallardo K, Debeaujon I, Vandekerckhove J, Job C, Job D. The effect of alpha-amanitin on the Arabidopsis seed proteome highlights the distinct roles of stored and neosynthesized mRNAs during germination. PLANT PHYSIOLOGY 2004; 134:1598-613. [PMID: 15047896 PMCID: PMC419834 DOI: 10.1104/pp.103.036293] [Citation(s) in RCA: 270] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2003] [Revised: 01/13/2004] [Accepted: 01/20/2004] [Indexed: 05/18/2023]
Abstract
To investigate the role of stored and neosynthesized mRNAs in seed germination, we examined the effect of alpha-amanitin, a transcriptional inhibitor targeting RNA polymerase II, on the germination of nondormant Arabidopsis seeds. We used transparent testa mutants, of which seed coat is highly permeable, to better ascertain that the drug can reach the embryo during seed imbibition. Even with the most permeable mutant (tt2-1), germination (radicle protrusion) occurred in the absence of transcription, while subsequent seedling growth was blocked. In contrast, germination was abolished in the presence of the translational inhibitor cycloheximide. Taken together, the results highlight the role of stored proteins and mRNAs for germination in Arabidopsis and show that in this species the potential for germination is largely programmed during the seed maturation process. The alpha-amanitin-resistant germination exhibited characteristic features. First, this germination was strongly slowed down, indicating that de novo transcription normally allows the synthesis of factor(s) activating the germination rate. Second, the sensitivity of germination to gibberellic acid was reduced 15-fold, confirming the role of this phytohormone in germination. Third, de novo synthesis of enzymes involved in reserve mobilization and resumption of metabolic activity was repressed, thus accounting for the failure in seedling establishment. Fourth, germinating seeds can recapitulate at least part of the seed maturation program, being capable of using mRNAs stored during development. Thus, commitment to germination and plant growth requires transcription of genes allowing the imbibed seed to discriminate between mRNAs to be utilized in germination and those to be destroyed.
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Affiliation(s)
- Loïc Rajjou
- Laboratoire Mixte Centre National de la Recherche Scientifique-Bayer CropScience, Bayer CropScience, F-69263 Lyon, France
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Lister R, Chew O, Lee MN, Heazlewood JL, Clifton R, Parker KL, Millar AH, Whelan J. A transcriptomic and proteomic characterization of the Arabidopsis mitochondrial protein import apparatus and its response to mitochondrial dysfunction. PLANT PHYSIOLOGY 2004; 134:777-89. [PMID: 14730085 PMCID: PMC344553 DOI: 10.1104/pp.103.033910] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2003] [Revised: 10/20/2003] [Accepted: 11/10/2003] [Indexed: 05/18/2023]
Abstract
Mitochondria import hundreds of cytosolically synthesized proteins via the mitochondrial protein import apparatus. Expression analysis in various organs of 19 components of the Arabidopsis mitochondrial protein import apparatus encoded by 31 genes showed that although many were present in small multigene families, often only one member was prominently expressed. This was supported by comparison of real-time reverse transcriptase-polymerase chain reaction and microarray experimental data with expressed sequence tag numbers and massive parallel signature sequence data. Mass spectrometric analysis of purified mitochondria identified 17 import components, their mitochondrial sub-compartment, and verified the presence of TIM8, TIM13, TIM17, TIM23, TIM44, TIM50, and METAXIN proteins for the first time, to our knowledge. Mass spectrometry-detected isoforms correlated with the most abundant gene transcript measured by expression data. Treatment of Arabidopsis cell culture with mitochondrial electron transport chain inhibitors rotenone and antimycin A resulted in a significant increase in transcript levels of import components, with a greater increase observed for the minor isoforms. The increase was observed 12 h after treatment, indicating that it was likely a secondary response. Microarray analysis of rotenone-treated cells indicated the up-regulation of gene sets involved in mitochondrial chaperone activity, protein degradation, respiratory chain assembly, and division. The rate of protein import into isolated mitochondria from rotenone-treated cells was halved, even though rotenone had no direct effect on protein import when added to mitochondria isolated from untreated cells. These findings suggest that transcription of import component genes is induced when mitochondrial function is limited and that minor gene isoforms display a greater response than the predominant isoforms.
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Affiliation(s)
- Ryan Lister
- Plant Molecular Biology Group, School of Biomedical and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
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Murcha MW, Lister R, Ho AYY, Whelan J. Identification, expression, and import of components 17 and 23 of the inner mitochondrial membrane translocase from Arabidopsis. PLANT PHYSIOLOGY 2003; 131:1737-47. [PMID: 12692332 PMCID: PMC166929 DOI: 10.1104/pp.102.016808] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2002] [Revised: 11/25/2002] [Accepted: 12/31/2002] [Indexed: 05/20/2023]
Abstract
Characterization of components 17 and 23 of the inner mitochondrial membrane translocase (TIM17:23) from Arabidopsis indicated that there were three genes present for TIM17 and TIM23 and two for TIM44. AtTIM17 differed from the yeast (Saccharomyces cerevisiae) and mammalian homologs in that two genes encoded proteins that were longer and one gene encoded a shorter protein. All Arabidopsis TIM23 predicted proteins appeared to lack the first 34 amino acids compared with yeast TIM23. All AtTIM17 and AtTIM23 genes were expressed but displayed different tissue and developmental profiles. Complementation of deletion mutants in yeast indicated that for AtTIM17, the extension at the C terminus not present in yeast had to be removed to achieve complementation, whereas for TIM23, a preprotein and amino acid transporter domain had to be present for complementation. Import assays with AtTIM17 and AtTIM23 indicated that they both contained internal signals for integration into the inner mitochondrial membrane in a membrane potential-dependent manner. The C terminus of imported AtTIM17-2 was susceptible to degradation by externally added protease with intact mitochondria. Removal of the 85 C-terminal amino acids resulted in import and full protection of the truncated protein. This suggests that the novel extension at the C terminus of AtTIM17-2 links the outer and inner membrane in a manner analogous to yeast TIM23.
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Affiliation(s)
- Monika W Murcha
- Plant Molecular Biology Group, Biochemistry and Molecular Biology, School of Biomedical and Chemical Sciences, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia
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Lister R, Mowday B, Whelan J, Millar AH. Zinc-dependent intermembrane space proteins stimulate import of carrier proteins into plant mitochondria. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 30:555-66. [PMID: 12047630 DOI: 10.1046/j.1365-313x.2002.01316.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mitochondrial inner membrane carrier proteins are imported into mitochondria from yeast, fungi and mammals by specific machinery, some components of which are distinct from those utilized by other proteins. Import of two different carriers into plant mitochondria showed that one contains a cleavable presequence which was processed during import, while the other imported in a valinomycin-sensitive manner without processing. Mild osmotic shock of mitochondria released intermembrane space (IMS) components and impaired carrier protein import. Adding back the released IMS proteins as a concentrate in the presence of micromolar ZnCl2 stimulated carrier import into IMS-depleted mitochondria, but did not stimulate import of a non-carrier control precursor protein, the alternative oxidase. Anion-exchange separation of IMS components before addition to IMS-depleted mitochondria revealed a correlation between several 9-10 kDa proteins and stimulation of carrier import. MS/MS sequencing of these proteins identified them as plant homologues of the yeast zinc-finger carrier import components Tim9 and Tim10. Stimulation of import was dependent on either Zn2+ or Cd2+ and inhibited by both N-ethylmalamide (NEM) and a divalent cation chelator, consistent with a functional requirement for a zinc finger protein. This represents direct functional evidence for a distinct carrier import pathway in plant mitochondria, and provides a tool for determining the potential function of other IMS proteins associated with protein import.
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Affiliation(s)
- Ryan Lister
- Plant Molecular Biology Group, School of Biomedical and Chemical Sciences, The University of Western Australia, Crawley 6009, WA, Australia
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Daley DO, Adams KL, Clifton R, Qualmann S, Millar AH, Palmer JD, Pratje E, Whelan J. Gene transfer from mitochondrion to nucleus: novel mechanisms for gene activation from Cox2. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 30:11-21. [PMID: 11967089 DOI: 10.1046/j.1365-313x.2002.01263.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The evolutionarily recent transfer of the gene for cytochrome c oxidase subunit 2 (cox2) from the mitochondrion to the nucleus in legumes is shown to have involved novel gene-activation steps. The acquired mitochondrial targeting presequence is bordered by two introns. Characterization of the import of soybean Cox2 indicates that the presequence is cleaved in a three-step process which is independent of assembly. The final processing step takes place only in the mitochondria of legume species, and not in several non-legume plants. The unusually long presequence of 136 amino acids consists of three regions: the first 20 amino acids are required for mitochondrial targeting and can be replaced by another presequence; the central portion of the presequence is required for efficient import of the Cox2 protein into mitochondria; and the last 12 amino acids, derived from the mitochondrially encoded protein, are required for correct maturation of the imported protein. The acquisition of a unique presequence, and the capacity for legume mitochondria to remove this presequence post-import, are considered to be essential adaptations for targeting of Cox2 to the mitochondrion and therefore activation of the transferred gene in the nucleus.
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Affiliation(s)
- Daniel O Daley
- Department of Biochemistry, University of Western Australia, Nedlands 6907, Australia
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Lister R, Chew O, Rudhe C, Lee MN, Whelan J. Arabidopsis thaliana ferrochelatase-I and -II are not imported into Arabidopsis mitochondria. FEBS Lett 2001; 506:291-5. [PMID: 11602264 DOI: 10.1016/s0014-5793(01)02925-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Using in vitro import assays into purified mitochondria and chloroplasts we found that Arabidopsis ferrochelatase-I and ferrochelatase-II were not imported into mitochondria purified from Arabidopsis (or several other plants) but were imported into pea leaf chloroplasts. Other dual targeted proteins could be imported into purified mitochondria from Arabidopsis. As only two ferrochelatase genes are present in the completed Arabidopsis genome, the presence of ferrochelatase activity in plant mitochondria needs to be re-evaluated. Previous reports of Arabidopsis ferrochelatase-I import into pea mitochondria are due to the fact that pea leaf (and root) mitochondria appear to import a variety, but not all chloroplast proteins. Thus pea mitochondria are not a suitable system to either study dual targeting, or to distinguish between isozymes present in mitochondria and chloroplasts.
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Affiliation(s)
- R Lister
- Department of Biochemistry, University of Western Australia, Crawley, Australia
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Considine MJ, Daley DO, Whelan J. The expression of alternative oxidase and uncoupling protein during fruit ripening in mango. PLANT PHYSIOLOGY 2001; 126:1619-29. [PMID: 11500560 PMCID: PMC117161 DOI: 10.1104/pp.126.4.1619] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2001] [Accepted: 05/07/2001] [Indexed: 05/19/2023]
Abstract
The expression of alternative oxidase (Aox) and uncoupling proteins (Ucp) was investigated during ripening in mango (Mangifera indica) and compared with the expression of peroxisomal thiolase, a previously described ripening marker in mango. The multigene family for the Aox in mango was expressed differentially during ripening. Abundance of Aox message and protein both peaked at the ripe stage. Expression of the single gene for the Ucp peaked at the turning stage and the protein abundance peaked at the ripe stage. Proteins of the cytochrome chain peaked at the mature stage of ripening. The pattern of protein accumulation suggested that increases in cytochrome chain components played an important role in facilitating the climacteric burst of respiration and that the Aox and Ucp may play a role in post-climacteric senescent processes. Because both message and protein for the Aox and Ucp increased in a similar pattern, it suggests that their expression is not controlled in a reciprocal manner but may be active simultaneously.
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Affiliation(s)
- M J Considine
- Department of Biochemistry, The University of Western Australia, Nedlands, Western Australia 6907, Australia
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