1
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Wei YM, Wang BH, Shao DJ, Yan RY, Wu JW, Zheng GM, Zhao YJ, Zhang XS, Zhao XY. Defective kernel 66 encodes a GTPase essential for kernel development in maize. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5694-5708. [PMID: 37490479 PMCID: PMC10540730 DOI: 10.1093/jxb/erad289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/24/2023] [Indexed: 07/27/2023]
Abstract
The mitochondrion is a semi-autonomous organelle that provides energy for cell activities through oxidative phosphorylation. In this study, we identified a defective kernel 66 (dek66)-mutant maize with defective kernels. We characterized a candidate gene, DEK66, encoding a ribosomal assembly factor located in mitochondria and possessing GTPase activity (which belongs to the ribosome biogenesis GTPase A family). In the dek66 mutant, impairment of mitochondrial structure and function led to the accumulation of reactive oxygen species and promoted programmed cell death in endosperm cells. Furthermore, the transcript levels of most of the key genes associated with nutrient storage, mitochondrial respiratory chain complex, and mitochondrial ribosomes in the dek66 mutant were significantly altered. Collectively, the results suggest that DEK66 is essential for the development of maize kernels by affecting mitochondrial function. This study provides a reference for understanding the impact of a mitochondrial ribosomal assembly factor in maize kernel development.
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Affiliation(s)
- Yi Ming Wei
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
- College of Life Sciences, Zaozhuang University, Zaozhuang, Shandong 277160, China
| | - Bo Hui Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Dong Jie Shao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
- College of Life Sciences, Zaozhuang University, Zaozhuang, Shandong 277160, China
| | - Ru Yu Yan
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Jia Wen Wu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Guang Ming Zheng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Ya Jie Zhao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Xian Sheng Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Xiang Yu Zhao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
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2
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Grüttner S, Nguyen TT, Bruhs A, Mireau H, Kempken F. The P-type pentatricopeptide repeat protein DWEORG1 is a non-previously reported rPPR protein of Arabidopsis mitochondria. Sci Rep 2022; 12:12492. [PMID: 35864185 PMCID: PMC9304396 DOI: 10.1038/s41598-022-16812-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 07/15/2022] [Indexed: 11/17/2022] Open
Abstract
Gene expression in plant mitochondria is mainly regulated by nuclear-encoded proteins on a post-transcriptional level. Pentatricopeptide repeat (PPR) proteins play a major role by participating in mRNA stability, splicing, RNA editing, and translation initiation. PPR proteins were also shown to be part of the mitochondrial ribosome (rPPR proteins), which may act as regulators of gene expression in plants. In this study, we focus on a mitochondrial-located P-type PPR protein—DWEORG1—from Arabidopsis thaliana. Its abundance in mitochondria is high, and it has a similar expression pattern as rPPR proteins. Mutant dweorg1 plants exhibit a slow-growth phenotype. Using ribosome profiling, a decrease in translation efficiency for cox2, rps4, rpl5, and ccmFN2 was observed in dweorg1 mutants, correlating with a reduced accumulation of the Cox2 protein in these plants. In addition, the mitochondrial rRNA levels are significantly reduced in dweorg1 compared with the wild type. DWEORG1 co-migrates with the ribosomal proteins Rps4 and Rpl16 in sucrose gradients, suggesting an association of DWEORG1 with the mitoribosome. Collectively, this data suggests that DWEORG1 encodes a novel rPPR protein that is needed for the translation of cox2, rps4, rpl5, and ccmFN2 and provides a stabilizing function for mitochondrial ribosomes.
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Affiliation(s)
- Stefanie Grüttner
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098, Kiel, Germany
| | - Tan-Trung Nguyen
- Institut Jean-Pierre Bourgin INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Anika Bruhs
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098, Kiel, Germany
| | - Hakim Mireau
- Institut Jean-Pierre Bourgin INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France.
| | - Frank Kempken
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098, Kiel, Germany.
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3
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Tomal A, Kwasniak-Owczarek M, Janska H. An Update on Mitochondrial Ribosome Biology: The Plant Mitoribosome in the Spotlight. Cells 2019; 8:E1562. [PMID: 31816993 PMCID: PMC6953067 DOI: 10.3390/cells8121562] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/28/2019] [Accepted: 12/01/2019] [Indexed: 02/06/2023] Open
Abstract
Contrary to the widely held belief that mitochondrial ribosomes (mitoribosomes) are highly similar to bacterial ones, recent experimental evidence reveals that mitoribosomes do differ significantly from their bacterial counterparts. This review is focused on plant mitoribosomes, but we also highlight the most striking similarities and differences between the plant and non-plant mitoribosomes. An analysis of the composition and structure of mitoribosomes in trypanosomes, yeast, mammals and plants uncovers numerous organism-specific features. For the plant mitoribosome, the most striking feature is the enormous size of the small subunit compared to the large one. Apart from the new structural information, possible functional peculiarities of different types of mitoribosomes are also discussed. Studies suggest that the protein composition of mitoribosomes is dynamic, especially during development, giving rise to a heterogeneous populations of ribosomes fulfilling specific functions. Moreover, convincing data shows that mitoribosomes interact with components involved in diverse mitochondrial gene expression steps, forming large expressosome-like structures.
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Affiliation(s)
| | | | - Hanna Janska
- Department of Cellular Molecular Biology, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.T.); (M.K.-O.)
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4
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Qi W, Lu L, Huang S, Song R. Maize Dek44 Encodes Mitochondrial Ribosomal Protein L9 and Is Required for Seed Development. PLANT PHYSIOLOGY 2019; 180:2106-2119. [PMID: 31182559 PMCID: PMC6670089 DOI: 10.1104/pp.19.00546] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 05/30/2019] [Indexed: 05/19/2023]
Abstract
Mitochondrial respiration depends on proteins encoded by the nuclear and mitochondrial genomes. Many respiratory chain-related proteins are encoded by the mitochondrial genome and undergo translation by mitochondrial ribosomes. The newly identified maize (Zea mays) defective kernel44 (dek44) mutant produces small kernels showing embryo-lethal phenotypes. We cloned Dek44 by isolating the Mutator tag that produced the mutation and identified it as encoding a putative 50S ribosomal protein L9. Subcellular fractionation by ultracentrifugation confirmed that DEK44 is a mitochondrial ribosomal protein. DEK44 is highly conserved in monocots and only accumulates in kernels. Transcriptome and reverse transcription quantitative PCR analyses revealed that loss of DEK44 function affects the expression of genes encoding respiratory chain-related proteins from the mitochondrial and nuclear genomes. Blue native-PAGE revealed significantly reduced assembly of respiratory chain complexes in dek44 mutant kernels. Transmission electron microscopy indicated that the biogenesis and morphology of mitochondria were strongly affected in dek44 mutant kernels. Furthermore, DEK44 might regulate cell growth and kernel development via cyclin/cyclin-dependent kinase-mediated activities. This study provides insight into the regulation of kernel development based on mitochondrial ribosomal protein function.
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Affiliation(s)
- Weiwei Qi
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Lei Lu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Shengchan Huang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Rentao Song
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Joint International Research Laboratory of Crop Molecular Breeding, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
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5
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Planchard N, Bertin P, Quadrado M, Dargel-Graffin C, Hatin I, Namy O, Mireau H. The translational landscape of Arabidopsis mitochondria. Nucleic Acids Res 2019; 46:6218-6228. [PMID: 29873797 PMCID: PMC6159524 DOI: 10.1093/nar/gky489] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 05/22/2018] [Indexed: 11/14/2022] Open
Abstract
Messenger RNA translation is a complex process that is still poorly understood in eukaryotic organelles like mitochondria. Growing evidence indicates though that mitochondrial translation differs from its bacterial counterpart in many key aspects. In this analysis, we have used ribosome profiling technology to generate a genome-wide snapshot view of mitochondrial translation in Arabidopsis. We show that, unlike in humans, most Arabidopsis mitochondrial ribosome footprints measure 27 and 28 bases. We also reveal that respiratory subunits encoding mRNAs show much higher ribosome association than other mitochondrial mRNAs, implying that they are translated at higher levels. Homogenous ribosome densities were generally detected within each respiratory complex except for complex V, where higher ribosome coverage corroborated with higher requirements for specific subunits. In complex I respiratory mutants, a reorganization of mitochondrial mRNAs ribosome association was detected involving increased ribosome densities for certain ribosomal protein encoding transcripts and a reduction in translation of a few complex V mRNAs. Taken together, our observations reveal that plant mitochondrial translation is a dynamic process and that translational control is important for gene expression in plant mitochondria. This study paves the way for future advances in the understanding translation in higher plant mitochondria.
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Affiliation(s)
- Noelya Planchard
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026 Versailles Cedex, France.,Paris-Sud University, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Pierre Bertin
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198 CEA, CNRS, Univ. Paris Sud, Bâtiment 400, 91405 Orsay, France
| | - Martine Quadrado
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026 Versailles Cedex, France
| | - Céline Dargel-Graffin
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026 Versailles Cedex, France
| | - Isabelle Hatin
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198 CEA, CNRS, Univ. Paris Sud, Bâtiment 400, 91405 Orsay, France
| | - Olivier Namy
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198 CEA, CNRS, Univ. Paris Sud, Bâtiment 400, 91405 Orsay, France
| | - Hakim Mireau
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026 Versailles Cedex, France
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6
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Robles P, Quesada V. Emerging Roles of Mitochondrial Ribosomal Proteins in Plant Development. Int J Mol Sci 2017; 18:ijms18122595. [PMID: 29207474 PMCID: PMC5751198 DOI: 10.3390/ijms18122595] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 11/28/2017] [Accepted: 12/01/2017] [Indexed: 11/26/2022] Open
Abstract
Mitochondria are the powerhouse of eukaryotic cells because they are responsible for energy production through the aerobic respiration required for growth and development. These organelles harbour their own genomes and translational apparatus: mitochondrial ribosomes or mitoribosomes. Deficient mitochondrial translation would impair the activity of this organelle, and is expected to severely perturb different biological processes of eukaryotic organisms. In plants, mitoribosomes consist of three rRNA molecules, encoded by the mitochondrial genome, and an undefined set of ribosomal proteins (mitoRPs), encoded by nuclear and organelle genomes. A detailed functional and structural characterisation of the mitochondrial translation apparatus in plants is currently lacking. In some plant species, presence of small gene families of mitoRPs whose members have functionally diverged has led to the proposal of the heterogeneity of the mitoribosomes. This hypothesis supports a dynamic composition of the mitoribosomes. Information on the effects of the impaired function of mitoRPs on plant development is extremely scarce. Nonetheless, several works have recently reported the phenotypic and molecular characterisation of plant mutants affected in mitoRPs that exhibit alterations in specific development aspects, such as embryogenesis, leaf morphogenesis or the formation of reproductive tissues. Some of these results would be in line with the ribosomal filter hypothesis, which proposes that ribosomes, besides being the machinery responsible for performing translation, are also able to regulate gene expression. This review describes the phenotypic effects on plant development displayed by the mutants characterised to date that are defective in genes which encode mitoRPs. The elucidation of plant mitoRPs functions will provide a better understanding of the mechanisms that control organelle gene expression and their contribution to plant growth and morphogenesis.
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Affiliation(s)
- Pedro Robles
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain.
| | - Víctor Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain.
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7
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Vincent T, Vingadassalon A, Ubrig E, Azeredo K, Srour O, Cognat V, Graindorge S, Salinas T, Maréchal-Drouard L, Duchêne AM. A genome-scale analysis of mRNAs targeting to plant mitochondria: upstream AUGs in 5' untranslated regions reduce mitochondrial association. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:1132-1142. [PMID: 29044717 DOI: 10.1111/tpj.13749] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 06/07/2023]
Abstract
Intracellular sorting of mRNAs is an essential process for regulating gene expression and protein localization. Most mitochondrial proteins are nuclear-encoded and imported into the mitochondria through post-translational or co-translational processes. In the latter case, mRNAs are found to be enriched in the vicinity of mitochondria. A genome-scale analysis of mRNAs associated with mitochondria has been performed to determine plant cytosolic mRNAs targeted to the mitochondrial surface. Many messengers encoding mitochondrial proteins were found associated with mitochondria. These mRNAs correspond to particular functions and complexes, such as respiration or mitoribosomes, which indicates a coordinated control of mRNA localization within metabolic pathways. In addition, upstream AUGs in 5' untranslated regions (UTRs), which modulate the translation efficiency of downstream sequences, were found to negatively affect the association of mRNAs with mitochondria. A mutational approach coupled with in vivo mRNA visualization confirmed this observation. Moreover, this technique allowed the identification of 3'-UTRs as another essential element for mRNA localization at the mitochondrial surface. Therefore, this work offers new insights into the mechanism, function and regulation of the association of cytosolic mRNAs with plant mitochondria.
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Affiliation(s)
- Timothée Vincent
- 'Bioimage and Bioinformatics' Platform, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Audrey Vingadassalon
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Elodie Ubrig
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Kevin Azeredo
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Ola Srour
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Valérie Cognat
- 'Bioimage and Bioinformatics' Platform, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Stéfanie Graindorge
- 'Bioimage and Bioinformatics' Platform, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Thalia Salinas
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Laurence Maréchal-Drouard
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
| | - Anne-Marie Duchêne
- 'Metabolism and Trafficking of RNA Within the Plant Cell' Team, Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, Strasbourg Cedex, 67084, France
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8
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Breiman A, Fieulaine S, Meinnel T, Giglione C. The intriguing realm of protein biogenesis: Facing the green co-translational protein maturation networks. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1864:531-50. [PMID: 26555180 DOI: 10.1016/j.bbapap.2015.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/05/2015] [Indexed: 01/13/2023]
Abstract
The ribosome is the cell's protein-making factory, a huge protein-RNA complex, that is essential to life. Determining the high-resolution structures of the stable "core" of this factory was among the major breakthroughs of the past decades, and was awarded the Nobel Prize in 2009. Now that the mysteries of the ribosome appear to be more traceable, detailed understanding of the mechanisms that regulate protein synthesis includes not only the well-known steps of initiation, elongation, and termination but also the less comprehended features of the co-translational events associated with the maturation of the nascent chains. The ribosome is a platform for co-translational events affecting the nascent polypeptide, including protein modifications, folding, targeting to various cellular compartments for integration into membrane or translocation, and proteolysis. These events are orchestrated by ribosome-associated protein biogenesis factors (RPBs), a group of a dozen or more factors that act as the "welcoming committee" for the nascent chain as it emerges from the ribosome. In plants these factors have evolved to fit the specificity of different cellular compartments: cytoplasm, mitochondria and chloroplast. This review focuses on the current state of knowledge of these factors and their interaction around the exit tunnel of dedicated ribosomes. Particular attention has been accorded to the plant system, highlighting the similarities and differences with other organisms.
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Affiliation(s)
- Adina Breiman
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Univ. Paris-Saclay 91198 Gif-sur-Yvette cedex, France; Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv 69978, Israel
| | - Sonia Fieulaine
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Univ. Paris-Saclay 91198 Gif-sur-Yvette cedex, France
| | - Thierry Meinnel
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Univ. Paris-Saclay 91198 Gif-sur-Yvette cedex, France
| | - Carmela Giglione
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Univ. Paris-Saclay 91198 Gif-sur-Yvette cedex, France.
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9
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Zhang H, Luo M, Day RC, Talbot MJ, Ivanova A, Ashton AR, Chaudhury AM, Macknight RC, Hrmova M, Koltunow AM. Developmentally regulated HEART STOPPER, a mitochondrially targeted L18 ribosomal protein gene, is required for cell division, differentiation, and seed development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:5867-80. [PMID: 26105995 PMCID: PMC4566979 DOI: 10.1093/jxb/erv296] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Evidence is presented for the role of a mitochondrial ribosomal (mitoribosomal) L18 protein in cell division, differentiation, and seed development after the characterization of a recessive mutant, heart stopper (hes). The hes mutant produced uncellularized endosperm and embryos arrested at the late globular stage. The mutant embryos differentiated partially on rescue medium with some forming callus. HES (At1g08845) encodes a mitochondrially targeted member of a highly diverged L18 ribosomal protein family. The substitution of a conserved amino residue in the hes mutant potentially perturbs mitoribosomal function via altered binding of 5S rRNA and/or influences the stability of the 50S ribosomal subunit, affecting mRNA binding and translation. Consistent with this, marker genes for mitochondrial dysfunction were up-regulated in the mutant. The slow growth of the endosperm and embryo indicates a defect in cell cycle progression, which is evidenced by the down-regulation of cell cycle genes. The down-regulation of other genes such as EMBRYO DEFECTIVE genes links the mitochondria to the regulation of many aspects of seed development. HES expression is developmentally regulated, being preferentially expressed in tissues with active cell division and differentiation, including developing embryos and the root tips. The divergence of the L18 family, the tissue type restricted expression of HES, and the failure of other L18 members to complement the hes phenotype suggest that the L18 proteins are involved in modulating development. This is likely via heterogeneous mitoribosomes containing different L18 members, which may result in differential mitochondrial functions in response to different physiological situations during development.
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Affiliation(s)
- Hongyu Zhang
- Rice Research Institute of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
| | - Ming Luo
- CSIRO Agriculture Flagship, PO Box 1600, ACT 2601, Australia
| | - Robert C Day
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Mark J Talbot
- CSIRO Agriculture Flagship, PO Box 1600, ACT 2601, Australia
| | - Aneta Ivanova
- CSIRO Agriculture Flagship, PO Box 1600, ACT 2601, Australia Present address: ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, WA 6009, Australia
| | | | - Abed M Chaudhury
- CSIRO Agriculture Flagship, PO Box 1600, ACT 2601, Australia Present address: VitaGrain, 232 Orchard Road, Level 9, Suite 232, Faber House, 238854 Singapore
| | | | - Maria Hrmova
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Anna M Koltunow
- CSIRO Agriculture Flagship, PO Box 350, Glen Osmond, SA 5064, Australia
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10
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Browning KS, Bailey-Serres J. Mechanism of cytoplasmic mRNA translation. THE ARABIDOPSIS BOOK 2015; 13:e0176. [PMID: 26019692 PMCID: PMC4441251 DOI: 10.1199/tab.0176] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein synthesis is a fundamental process in gene expression that depends upon the abundance and accessibility of the mRNA transcript as well as the activity of many protein and RNA-protein complexes. Here we focus on the intricate mechanics of mRNA translation in the cytoplasm of higher plants. This chapter includes an inventory of the plant translational apparatus and a detailed review of the translational processes of initiation, elongation, and termination. The majority of mechanistic studies of cytoplasmic translation have been carried out in yeast and mammalian systems. The factors and mechanisms of translation are for the most part conserved across eukaryotes; however, some distinctions are known to exist in plants. A comprehensive understanding of the complex translational apparatus and its regulation in plants is warranted, as the modulation of protein production is critical to development, environmental plasticity and biomass yield in diverse ecosystems and agricultural settings.
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Affiliation(s)
- Karen S. Browning
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin TX 78712-0165
- Both authors contributed equally to this work
| | - Julia Bailey-Serres
- Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, CA, 92521 USA
- Both authors contributed equally to this work
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11
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Lightowlers RN, Rozanska A, Chrzanowska-Lightowlers ZM. Mitochondrial protein synthesis: figuring the fundamentals, complexities and complications, of mammalian mitochondrial translation. FEBS Lett 2014; 588:2496-503. [PMID: 24911204 PMCID: PMC4099522 DOI: 10.1016/j.febslet.2014.05.054] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 05/28/2014] [Accepted: 05/29/2014] [Indexed: 12/28/2022]
Abstract
Mitochondrial protein synthesis is essential for all mammals, being responsible for providing key components of the oxidative phosphorylation complexes. Although only thirteen different polypeptides are made, the molecular details of this deceptively simple process remain incomplete. Central to this process is a non-canonical ribosome, the mitoribosome, which has evolved to address its unique mandate. In this review, we integrate the current understanding of the molecular aspects of mitochondrial translation with recent advances in structural biology. We identify numerous key questions that we will need to answer if we are to increase our knowledge of the molecular mechanisms underlying mitochondrial protein synthesis.
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Affiliation(s)
- Robert N Lightowlers
- The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Agata Rozanska
- The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Zofia M Chrzanowska-Lightowlers
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Gonzalez DH, Giegé P. Biogenesis of the oxidative phosphorylation machinery in plants. From gene expression to complex assembly. FRONTIERS IN PLANT SCIENCE 2014; 5:225. [PMID: 24904620 PMCID: PMC4033214 DOI: 10.3389/fpls.2014.00225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 05/05/2014] [Indexed: 05/20/2023]
Affiliation(s)
- Daniel H. Gonzalez
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Universidad Nacional del LitoralSanta Fe, Argentina
- *Correspondence: ;
| | - Philippe Giegé
- Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire des Plantes du CNRS (IBMP-CNRS), Université de StrasbourgStrasbourg, France
- *Correspondence: ;
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