1
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Song C, Li Y, Yang M, Li T, Hou Y, Liu Y, Xu C, Liu J, Millar AH, Wang N, Li L. Protein aggregation in plant mitochondria lacking Lon1 inhibits translation and induces unfolded protein responses. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38988259 DOI: 10.1111/pce.15035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 06/20/2024] [Accepted: 06/27/2024] [Indexed: 07/12/2024]
Abstract
Loss of Lon1 led to stunted plant growth and accumulation of nuclear-encoded mitochondrial proteins including Lon1 substrates. However, an in-depth label-free proteomics quantification of mitochondrial proteins in lon1 revealed that the majority of mitochondrial-encoded proteins decreased in abundance. Additionally, we found that lon1 mutants contained protein aggregates in the mitochondrial that were enriched in metabolic enzymes, ribosomal subunits and PPR-containing proteins of the translation apparatus. These mutants exhibited reduced general mitochondrial translation as well as deficiencies in RNA splicing and editing. These findings support the role of Lon1 in maintaining a functional translational apparatus for mitochondrial-encoded gene translation. Transcriptome analysis of lon1 revealed a mitochondrial unfolded protein response reminiscent of the mitochondrial retrograde signalling dependent on the transcription factor ANAC017. Notably, lon1 mutants exhibited transiently elevated ethylene production, and the shortened hypocotyl observed in lon1 mutants during skotomorphogenesis was partially alleviated by ethylene inhibitors. Furthermore, the short root phenotype was partially ameliorated by introducing a mutation in the ethylene receptor ETR1. Interestingly, the upregulation of only a select few target genes was linked to ETR1-mediated ethylene signalling. Together this provides multiple steps in the link between loss of Lon1 and signalling responses to restore mitochondrial protein homoeostasis in plants.
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Affiliation(s)
- Ce Song
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yuanyuan Li
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Mengmeng Yang
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Tiantian Li
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yuqi Hou
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yinyin Liu
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Chang Xu
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jinjian Liu
- Key Laboratory of Radiopharmacokinetics for Innovative Drugs, Chinese Academy of Medical Sciences, and Institute of Radiation Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, Crawley, Western Australia, Australia
| | - Ningning Wang
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Lei Li
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
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2
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Song C, Hou Y, Li T, Liu Y, Wang XA, Qu W, Li L. Lon1 Inactivation Downregulates Autophagic Flux and Brassinosteroid Biogenesis, Modulating Mitochondrial Proportion and Seed Development in Arabidopsis. Int J Mol Sci 2024; 25:5425. [PMID: 38791463 PMCID: PMC11121791 DOI: 10.3390/ijms25105425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/11/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
Mitochondrial protein homeostasis is crucially regulated by protein degradation processes involving both mitochondrial proteases and cytosolic autophagy. However, it remains unclear how plant cells regulate autophagy in the scenario of lacking a major mitochondrial Lon1 protease. In this study, we observed a notable downregulation of core autophagy proteins in Arabidopsis Lon1 knockout mutant lon1-1 and lon1-2, supporting the alterations in the relative proportions of mitochondrial and vacuolar proteins over total proteins in the plant cells. To delve deeper into understanding the roles of the mitochondrial protease Lon1 and autophagy in maintaining mitochondrial protein homeostasis and plant development, we generated the lon1-2atg5-1 double mutant by incorporating the loss-of-function mutation of the autophagy core protein ATG5, known as atg5-1. The double mutant exhibited a blend of phenotypes, characterized by short plants and early senescence, mirroring those observed in the individual single mutants. Accordingly, distinct transcriptome alterations were evident in each of the single mutants, while the double mutant displayed a unique amalgamation of transcriptional responses. Heightened severity, particularly evident in reduced seed numbers and abnormal embryo development, was observed in the double mutant. Notably, aberrations in protein storage vacuoles (PSVs) and oil bodies were evident in the single and double mutants. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of genes concurrently downregulated in lon1-2, atg5-1, and lon1-2atg5-1 unveiled a significant suppression of genes associated with brassinosteroid (BR) biosynthesis and homeostasis. This downregulation likely contributes to the observed abnormalities in seed and embryo development in the mutants.
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Affiliation(s)
| | | | | | | | | | | | - Lei Li
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China; (C.S.); (Y.H.); (T.L.); (Y.L.); (X.-A.W.); (W.Q.)
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3
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Zhang Y, Jaime SM, Bulut M, Graf A, Fernie AR. The conditional mitochondrial protein complexome in the Arabidopsis thaliana root and shoot. PLANT COMMUNICATIONS 2023; 4:100635. [PMID: 37291828 PMCID: PMC10504587 DOI: 10.1016/j.xplc.2023.100635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 02/23/2023] [Accepted: 06/02/2023] [Indexed: 06/10/2023]
Abstract
Protein complexes are important for almost all biological processes. Hence, to fully understand how cells work, it is also necessary to characterize protein complexes and their dynamics in response to various cellular cues. Moreover, the dynamics of protein interaction play crucial roles in regulating the (dis)association of protein complexes and, in turn, regulating biological processes such as metabolism. Here, mitochondrial protein complexes were investigated by blue native PAGE and size-exclusion chromatography under conditions of oxidative stress in order to monitor their dynamic (dis)associations. Rearrangements of enzyme interactions and changes in protein complex abundance were observed in response to oxidative stress induced by menadione treatment. These included changes in enzymatic protein complexes involving γ-amino butyric acid transaminase (GABA-T), Δ-ornithine aminotransferase (Δ-OAT), or proline dehydrogenase 1 (POX1) that are expected to affect proline metabolism. Menadione treatment also affected interactions between several enzymes of the tricarboxylic acid (TCA) cycle and the abundance of complexes of the oxidative phosphorylation pathway. In addition, we compared the mitochondrial complexes of roots and shoots. Considerable differences between the two tissues were observed in the mitochondrial import/export apparatus, the formation of super-complexes in the oxidative phosphorylation pathway, and specific interactions between enzymes of the TCA cycle that we postulate may be related to the metabolic/energetic requirements of roots and shoots.
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Affiliation(s)
- Youjun Zhang
- Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria; Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Silvia Martínez Jaime
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Mustafa Bulut
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Alexander Graf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
| | - Alisdair R Fernie
- Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria; Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
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4
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Pedroletti L, Moseler A, Meyer AJ. Assembly, transfer, and fate of mitochondrial iron-sulfur clusters. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:3328-3344. [PMID: 36846908 DOI: 10.1093/jxb/erad062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/13/2023] [Indexed: 06/08/2023]
Abstract
Since the discovery of an autonomous iron-sulfur cluster (Fe-S) assembly machinery in mitochondria, significant efforts to examine the nature of this process have been made. The assembly of Fe-S clusters occurs in two distinct steps with the initial synthesis of [2Fe-2S] clusters by a first machinery followed by a subsequent assembly into [4Fe-4S] clusters by a second machinery. Despite this knowledge, we still have only a rudimentary understanding of how Fe-S clusters are transferred and distributed among their respective apoproteins. In particular, demand created by continuous protein turnover and the sacrificial destruction of clusters for synthesis of biotin and lipoic acid reveal possible bottlenecks in the supply chain of Fe-S clusters. Taking available information from other species into consideration, this review explores the mitochondrial assembly machinery of Arabidopsis and provides current knowledge about the respective transfer steps to apoproteins. Furthermore, this review highlights biotin synthase and lipoyl synthase, which both utilize Fe-S clusters as a sulfur source. After extraction of sulfur atoms from these clusters, the remains of the clusters probably fall apart, releasing sulfide as a highly toxic by-product. Immediate refixation through local cysteine biosynthesis is therefore an essential salvage pathway and emphasizes the physiological need for cysteine biosynthesis in plant mitochondria.
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Affiliation(s)
- Luca Pedroletti
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, D-53113 Bonn, Germany
| | - Anna Moseler
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, D-53113 Bonn, Germany
| | - Andreas J Meyer
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, D-53113 Bonn, Germany
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5
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Ghifari AS, Saha S, Murcha MW. The biogenesis and regulation of the plant oxidative phosphorylation system. PLANT PHYSIOLOGY 2023; 192:728-747. [PMID: 36806687 DOI: 10.1093/plphys/kiad108] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/19/2023] [Accepted: 01/22/2023] [Indexed: 06/01/2023]
Abstract
Mitochondria are central organelles for respiration in plants. At the heart of this process is oxidative phosphorylation (OXPHOS) system, which generates ATP required for cellular energetic needs. OXPHOS complexes comprise of multiple subunits that originated from both mitochondrial and nuclear genome, which requires careful orchestration of expression, translation, import, and assembly. Constant exposure to reactive oxygen species due to redox activity also renders OXPHOS subunits to be more prone to oxidative damage, which requires coordination of disassembly and degradation. In this review, we highlight the composition, assembly, and activity of OXPHOS complexes in plants based on recent biochemical and structural studies. We also discuss how plants regulate the biogenesis and turnover of OXPHOS subunits and the importance of OXPHOS in overall plant respiration. Further studies in determining the regulation of biogenesis and activity of OXPHOS will advances the field, especially in understanding plant respiration and its role to plant growth and development.
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Affiliation(s)
- Abi S Ghifari
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
| | - Saurabh Saha
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
| | - Monika W Murcha
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
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6
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García Pascual B, Nordbotten JM, Johnston IG. Cellular and environmental dynamics influence species-specific extents of organelle gene retention. Proc Biol Sci 2023; 290:20222140. [PMID: 36883279 PMCID: PMC9993063 DOI: 10.1098/rspb.2022.2140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Mitochondria and plastids rely on many nuclear-encoded genes, but retain small subsets of the genes they need to function in their own organelle DNA (oDNA). Different species retain different numbers of oDNA genes, and the reasons for these differences are not completely understood. Here, we use a mathematical model to explore the hypothesis that the energetic demands imposed by an organism's changing environment influence how many oDNA genes it retains. The model couples the physical biology of cell processes of gene expression and transport to a supply-and-demand model for the environmental dynamics to which an organism is exposed. The trade-off between fulfilling metabolic and bioenergetic environmental demands, and retaining genetic integrity, is quantified for a generic gene encoded either in oDNA or in nuclear DNA. Species in environments with high-amplitude, intermediate-frequency oscillations are predicted to retain the most organelle genes, whereas those in less dynamic or noisy environments the fewest. We discuss support for, and insight from, these predictions with oDNA data across eukaryotic taxa, including high oDNA gene counts in sessile organisms exposed to day-night and intertidal oscillations (including plants and algae) and low counts in parasites and fungi.
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Affiliation(s)
| | | | - Iain G. Johnston
- Department of Mathematics, University of Bergen, Bergen, Norway
- Computational Biology Unit, University of Bergen, Bergen, Norway
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7
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Sun Y, Li J, Zhang L, Lin R. Regulation of chloroplast protein degradation. J Genet Genomics 2023:S1673-8527(23)00049-8. [PMID: 36863685 DOI: 10.1016/j.jgg.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/02/2023] [Accepted: 02/14/2023] [Indexed: 03/04/2023]
Abstract
Chloroplasts are unique organelles that not only provide sites for photosynthesis and many metabolic processes, but also are sensitive to various environmental stresses. Chloroplast proteins are encoded by genes from both nuclear and chloroplast genomes. During chloroplast development and responses to stresses, the robust protein quality control systems are essential for regulation of protein homeostasis and the integrity of chloroplast proteome. In this review, we summarize the regulatory mechanisms of chloroplast protein degradation refer to protease system, ubiquitin-proteasome system, and the chloroplast autophagy. These mechanisms symbiotically play a vital role in chloroplast development and photosynthesis under both normal or stress conditions.
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Affiliation(s)
- Yang Sun
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, Henan 475001, China
| | - Jialong Li
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Lixin Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, Henan 475001, China.
| | - Rongcheng Lin
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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8
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Lee HY, Hwang OJ, Back K. Phytomelatonin as a signaling molecule for protein quality control via chaperone, autophagy, and ubiquitin-proteasome systems in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5863-5873. [PMID: 35246975 DOI: 10.1093/jxb/erac002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
Physiological effects mediated by melatonin are attributable to its potent antioxidant activity as well as its role as a signaling molecule in inducing a vast array of melatonin-mediated genes. Here, we propose melatonin as a signaling molecule essential for protein quality control (PQC) in plants. PQC occurs by the coordinated activities of three systems: the chaperone network, autophagy, and the ubiquitin-proteasome system. With regard to the melatonin-mediated chaperone pathway, melatonin increases thermotolerance by induction of heat shock proteins and confers endoplasmic reticulum stress tolerance by increasing endoplasmic reticulum chaperone proteins. In chloroplasts, melatonin-induced chaperones, including Clps and CpHSP70s, play key roles in the PQC of chloroplast-localized proteins, such as Lhcb1, Lhcb4, and RBCL, during growth. Melatonin regulates PQC by autophagy processes, in which melatonin induces many autophagy (ATG) genes and autophagosome formation under stress conditions. Finally, melatonin-mediated plant stress tolerance is associated with up-regulation of stress-induced transcription factors, which are regulated by the ubiquitin-proteasome system. In this review, we propose that melatonin plays a pivotal role in PQC and consequently functions as a pleiotropic molecule under non-stress and adverse conditions in plants.
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Affiliation(s)
- Hyoung Yool Lee
- Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
| | - Ok Jin Hwang
- Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
| | - Kyoungwhan Back
- Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
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9
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Proteolytic regulation of mitochondrial oxidative phosphorylation components in plants. Biochem Soc Trans 2022; 50:1119-1132. [PMID: 35587610 PMCID: PMC9246333 DOI: 10.1042/bst20220195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/07/2022] [Accepted: 05/03/2022] [Indexed: 11/28/2022]
Abstract
Mitochondrial function relies on the homeostasis and quality control of their proteome, including components of the oxidative phosphorylation (OXPHOS) pathway that generates energy in form of ATP. OXPHOS subunits are under constant exposure to reactive oxygen species due to their oxidation-reduction activities, which consequently make them prone to oxidative damage, misfolding, and aggregation. As a result, quality control mechanisms through turnover and degradation are required for maintaining mitochondrial activity. Degradation of OXPHOS subunits can be achieved through proteomic turnover or modular degradation. In this review, we present multiple protein degradation pathways in plant mitochondria. Specifically, we focus on the intricate turnover of OXPHOS subunits, prior to protein import via cytosolic proteasomal degradation and post import and assembly via intra-mitochondrial proteolysis involving multiple AAA+ proteases. Together, these proteolytic pathways maintain the activity and homeostasis of OXPHOS components.
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10
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Giannakis K, Chustecki JM, Johnston IG. Exchange on dynamic encounter networks allows plant mitochondria to collect complete sets of mitochondrial DNA products despite their incomplete genomes. QUANTITATIVE PLANT BIOLOGY 2022; 3:e18. [PMID: 37077986 PMCID: PMC10095876 DOI: 10.1017/qpb.2022.15] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 05/03/2023]
Abstract
Mitochondria in plant cells usually contain less than a full copy of the mitochondrial DNA (mtDNA) genome. Here, we asked whether mitochondrial dynamics may allow individual mitochondria to 'collect' a full set of mtDNA-encoded gene products over time, by facilitating exchange between individuals akin to trade on a social network. We characterise the collective dynamics of mitochondria in Arabidopsis hypocotyl cells using a recent approach combining single-cell time-lapse microscopy, video analysis and network science. We use a quantitative model to predict the capacity for sharing genetic information and gene products through the networks of encounters between mitochondria. We find that biological encounter networks support the emergence of gene product sets over time more readily than a range of other possible network structures. Using results from combinatorics, we identify the network statistics that determine this propensity, and discuss how features of mitochondrial dynamics observed in biology facilitate the collection of mtDNA-encoded gene products.
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Affiliation(s)
| | | | - Iain G. Johnston
- Department of Mathematics, University of Bergen, Bergen, Norway
- Computational Biology Unit, University of Bergen, Bergen, Norway
- Author for correspondence: I. G. Johnston, E-mail:
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11
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Zou Y, Bozhkov PV. Chlamydomonas proteases: classification, phylogeny, and molecular mechanisms. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:7680-7693. [PMID: 34468747 PMCID: PMC8643629 DOI: 10.1093/jxb/erab383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/13/2021] [Indexed: 05/08/2023]
Abstract
Proteases can regulate myriad biochemical pathways by digesting or processing target proteins. While up to 3% of eukaryotic genes encode proteases, only a tiny fraction of proteases are mechanistically understood. Furthermore, most of the current knowledge about proteases is derived from studies of a few model organisms, including Arabidopsis thaliana in the case of plants. Proteases in other plant model systems are largely unexplored territory, limiting our mechanistic comprehension of post-translational regulation in plants and hampering integrated understanding of how proteolysis evolved. We argue that the unicellular green alga Chlamydomonas reinhardtii has a number of technical and biological advantages for systematic studies of proteases, including reduced complexity of many protease families and ease of cell phenotyping. With this end in view, we share a genome-wide inventory of proteolytic enzymes in Chlamydomonas, compare the protease degradomes of Chlamydomonas and Arabidopsis, and consider the phylogenetic relatedness of Chlamydomonas proteases to major taxonomic groups. Finally, we summarize the current knowledge of the biochemical regulation and physiological roles of proteases in this algal model. We anticipate that our survey will promote and streamline future research on Chlamydomonas proteases, generating new insights into proteolytic mechanisms and the evolution of digestive and limited proteolysis.
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Affiliation(s)
- Yong Zou
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Peter V Bozhkov
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
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12
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Sharma P, Gayen D. Plant protease as regulator and signaling molecule for enhancing environmental stress-tolerance. PLANT CELL REPORTS 2021; 40:2081-2095. [PMID: 34173047 DOI: 10.1007/s00299-021-02739-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
Proteases are ubiquitous in prokaryotes and eukaryotes. Plant proteases are key regulators of various physiological processes, including protein homeostasis, organelle development, senescence, seed germination, protein processing, environmental stress response, and programmed cell death. Proteases are involved in the breakdown of peptide bonds resulting in irreversible posttranslational modification of the protein. Proteases act as signaling molecules that specifically regulate cellular function by cleaving and triggering receptor molecules. Peptides derived from proteolysis regulate ROS signaling under oxidative stress in the plant. It degrades misfolded and abnormal proteins into amino acids to repair the cell damage and regulates the biological process in response to environmental stress. Proteases modulate the biogenesis of phytohormones which control plant growth, development, and environmental stresses. Protein homeostasis, the overall balance between protein synthesis and proteolysis, is required for plant growth and development. Abiotic and biotic stresses are major factors that negatively impact cellular survivability, biomass production, and reduced crop yield potentials. Therefore, the identification of various stress-responsive proteases and their molecular functions may elucidate valuable information for the development of stress-resilient crops with higher yield potentials. However, the understanding of molecular mechanisms of plant protease remains unexplored. This review provides an overview of proteases related to development, signaling, and growth regulation to acclimatize environmental stress in plants.
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Affiliation(s)
- Punam Sharma
- Department of Biochemistry, Central University of Rajasthan, Ajmer, 305817, Rajasthan, India
| | - Dipak Gayen
- Department of Biochemistry, Central University of Rajasthan, Ajmer, 305817, Rajasthan, India.
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13
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Chen Y, Wang Y, Yang J, Zhou W, Dai S. Exploring the diversity of plant proteome. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1197-1210. [PMID: 33650765 DOI: 10.1111/jipb.13087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/25/2021] [Indexed: 05/10/2023]
Abstract
The tremendous functional, spatial, and temporal diversity of the plant proteome is regulated by multiple factors that continuously modify protein abundance, modifications, interactions, localization, and activity to meet the dynamic needs of plants. Dissecting the proteome complexity and its underlying genetic variation is attracting increasing research attention. Mass spectrometry (MS)-based proteomics has become a powerful approach in the global study of protein functions and their relationships on a systems level. Here, we review recent breakthroughs and strategies adopted to unravel the diversity of the proteome, with a specific focus on the methods used to analyze posttranslational modifications (PTMs), protein localization, and the organization of proteins into functional modules. We also consider PTM crosstalk and multiple PTMs temporally regulating the life cycle of proteins. Finally, we discuss recent quantitative studies using MS to measure protein turnover rates and examine future directions in the study of the plant proteome.
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Affiliation(s)
- Yanmei Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yi Wang
- State Key Laboratory of Wheat and Maize Crop Science, College of Resources and Environment, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jun Yang
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Wenbin Zhou
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Shaojun Dai
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
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14
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Van Aken O. Mitochondrial redox systems as central hubs in plant metabolism and signaling. PLANT PHYSIOLOGY 2021; 186:36-52. [PMID: 33624829 PMCID: PMC8154082 DOI: 10.1093/plphys/kiab101] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/11/2021] [Indexed: 05/06/2023]
Abstract
Plant mitochondria are indispensable for plant metabolism and are tightly integrated into cellular homeostasis. This review provides an update on the latest research concerning the organization and operation of plant mitochondrial redox systems, and how they affect cellular metabolism and signaling, plant development, and stress responses. New insights into the organization and operation of mitochondrial energy systems such as the tricarboxylic acid cycle and mitochondrial electron transport chain (mtETC) are discussed. The mtETC produces reactive oxygen and nitrogen species, which can act as signals or lead to cellular damage, and are thus efficiently removed by mitochondrial antioxidant systems, including Mn-superoxide dismutase, ascorbate-glutathione cycle, and thioredoxin-dependent peroxidases. Plant mitochondria are tightly connected with photosynthesis, photorespiration, and cytosolic metabolism, thereby providing redox-balancing. Mitochondrial proteins are targets of extensive post-translational modifications, but their functional significance and how they are added or removed remains unclear. To operate in sync with the whole cell, mitochondria can communicate their functional status via mitochondrial retrograde signaling to change nuclear gene expression, and several recent breakthroughs here are discussed. At a whole organism level, plant mitochondria thus play crucial roles from the first minutes after seed imbibition, supporting meristem activity, growth, and fertility, until senescence of darkened and aged tissue. Finally, plant mitochondria are tightly integrated with cellular and organismal responses to environmental challenges such as drought, salinity, heat, and submergence, but also threats posed by pathogens. Both the major recent advances and outstanding questions are reviewed, which may help future research efforts on plant mitochondria.
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Affiliation(s)
- Olivier Van Aken
- Department of Biology, Lund University, Lund, Sweden
- Author for communication:
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15
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The composition and turnover of the Arabidopsis thaliana 80S cytosolic ribosome. Biochem J 2021; 477:3019-3032. [PMID: 32744327 PMCID: PMC7452503 DOI: 10.1042/bcj20200385] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/26/2020] [Accepted: 08/03/2020] [Indexed: 12/13/2022]
Abstract
Cytosolic 80S ribosomes contain proteins of the mature cytosolic ribosome (r-proteins) as well as proteins with roles in ribosome biogenesis, protein folding or modification. Here, we refined the core r-protein composition in Arabidopsis thaliana by determining the abundance of different proteins during enrichment of ribosomes from cell cultures using peptide mass spectrometry. The turnover rates of 26 40S subunit r-proteins and 29 60S subunit r-proteins were also determined, showing that half of the ribosome population is replaced every 3–4 days. Three enriched proteins showed significantly shorter half-lives; a protein annotated as a ribosomal protein uL10 (RPP0D, At1g25260) with a half-life of 0.5 days and RACK1b and c with half-lives of 1–1.4 days. The At1g25260 protein is a homologue of the human Mrt4 protein, a trans-acting factor in the assembly of the pre-60S particle, while RACK1 has known regulatory roles in cell function beyond its role in the 40S subunit. Our experiments also identified 58 proteins that are not from r-protein families but co-purify with ribosomes and co-express with r-proteins; 26 were enriched more than 10-fold during ribosome enrichment. Some of these enriched proteins have known roles in translation, while others are newly proposed ribosome-associated factors in plants. This analysis provides an improved understanding of A. thaliana ribosome protein content, shows that most r-proteins turnover in unison in vivo, identifies a novel set of potential plant translatome components, and how protein turnover can help identify r-proteins involved in ribosome biogenesis or regulation in plants.
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16
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Sun JL, Li JY, Wang MJ, Song ZT, Liu JX. Protein Quality Control in Plant Organelles: Current Progress and Future Perspectives. MOLECULAR PLANT 2021; 14:95-114. [PMID: 33137518 DOI: 10.1016/j.molp.2020.10.011] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 10/09/2020] [Accepted: 10/28/2020] [Indexed: 05/20/2023]
Abstract
The endoplasmic reticulum, chloroplasts, and mitochondria are major plant organelles for protein synthesis, photosynthesis, metabolism, and energy production. Protein homeostasis in these organelles, maintained by a balance between protein synthesis and degradation, is essential for cell functions during plant growth, development, and stress resistance. Nucleus-encoded chloroplast- and mitochondrion-targeted proteins and ER-resident proteins are imported from the cytosol and undergo modification and maturation within their respective organelles. Protein folding is an error-prone process that is influenced by both developmental signals and environmental cues; a number of mechanisms have evolved to ensure efficient import and proper folding and maturation of proteins in plant organelles. Misfolded or damaged proteins with nonnative conformations are subject to degradation via complementary or competing pathways: intraorganelle proteases, the organelle-associated ubiquitin-proteasome system, and the selective autophagy of partial or entire organelles. When proteins in nonnative conformations accumulate, the organelle-specific unfolded protein response operates to restore protein homeostasis by reducing protein folding demand, increasing protein folding capacity, and enhancing components involved in proteasome-associated protein degradation and autophagy. This review summarizes recent progress on the understanding of protein quality control in the ER, chloroplasts, and mitochondria in plants, with a focus on common mechanisms shared by these organelles during protein homeostasis.
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Affiliation(s)
- Jing-Liang Sun
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310027, China
| | - Jin-Yu Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310027, China
| | - Mei-Jing Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310027, China
| | - Ze-Ting Song
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310027, China
| | - Jian-Xiang Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310027, China.
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Huang S, Petereit J, Millar AH. Loss of conserved mitochondrial CLPP and its functions lead to different phenotypes in plants and other organisms. PLANT SIGNALING & BEHAVIOR 2020; 15:1831789. [PMID: 33073672 PMCID: PMC7671067 DOI: 10.1080/15592324.2020.1831789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Caseinolytic protease (CLPP) is an energy-dependent serine-type protease that plays a role in protein quality control. The CLPP gene is highly conserved across kingdoms and the protein is present in both bacteria and eukaryote organelles like mitochondria across a wide phylogenetic range. This pedigree has all the hallmarks of CLPP being an essential gene. However, in plants, disruption of mitochondrial CLPP has no impact on its growth, reminiscent of its nonessential role in some model fungi. Deletion of mitochondrial CLPP improves health and increased life span in the filamentous fungus, Podospora anserina, while loss of human mitochondrial CLPP leads to infertility and hearing loss. Recently it was revealed that both plant and human CLPP share a similar role in maintenance of the N-module of respiratory complex I. In addition, plant mitochondrial CLPP also coordinates the homeostasis of other mitochondrial protein complexes encoded by genes across mitochondrial and nuclear genomes. Understanding the contextual role of mitochondrial CLPP across kingdoms may help to understand these diverse sets of clpp phenotypes and the widespread conservation of CLPP genes.
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Affiliation(s)
- Shaobai Huang
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, Australia
| | - Jakob Petereit
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, Australia
| | - A. Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, Australia
- CONTACT A. Harvey Millar ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley 6009, Perth, Western Australia
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18
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Wijerathna-Yapa A, Stroeher E, Fenske R, Li L, Duncan O, Millar AH. Proteomics for Autophagy Receptor and Cargo Identification in Plants. J Proteome Res 2020; 20:129-138. [PMID: 33241938 DOI: 10.1021/acs.jproteome.0c00609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Autophagy is a catabolic process facilitating the degradation of cytoplasmic proteins and organelles in a lysosome- or vacuole-dependent manner in plants, animals, and fungi. Proteomic studies have demonstrated that autophagy controls and shapes the proteome and has identified both receptor and cargo proteins inside autophagosomes. In a smaller selection of studies, proteomics has been used for the analysis of post-translational modifications that target proteins for elimination and protein-protein interactions between receptors and cargo, providing a better understanding of the complex regulatory processes controlling autophagy. In this perspective, we highlight how proteomic studies have contributed to our understanding of autophagy in plants against the backdrop of yeast and animal studies. We then provide a framework for how the future application of proteomics in plant autophagy can uncover the mechanisms and outcomes of sculpting organelles during plant development, particularly through the identification of autophagy receptors and cargo in plants.
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Affiliation(s)
- Akila Wijerathna-Yapa
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009 Crawley, Western Australia, Australia
| | - Elke Stroeher
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009 Crawley, Western Australia, Australia
| | - Ricarda Fenske
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009 Crawley, Western Australia, Australia
| | - Lei Li
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009 Crawley, Western Australia, Australia.,Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, 300071 Tianjin, China
| | - Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009 Crawley, Western Australia, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009 Crawley, Western Australia, Australia
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19
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Salih KJ, Duncan O, Li L, O'Leary B, Fenske R, Trösch J, Millar AH. Impact of oxidative stress on the function, abundance, and turnover of the Arabidopsis 80S cytosolic ribosome. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:128-139. [PMID: 32027433 DOI: 10.1111/tpj.14713] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 01/05/2020] [Accepted: 01/23/2020] [Indexed: 05/22/2023]
Abstract
Abiotic stress in plants causes accumulation of reactive oxygen species (ROS) leading to the need for new protein synthesis to defend against ROS and to replace existing proteins that are damaged by oxidation. Functional plant ribosomes are critical for these activities, however we know little about the impact of oxidative stress on plant ribosome abundance, turnover, and function. Using Arabidopsis cell culture as a model system, we induced oxidative stress using 1 µm of H2 O2 or 5 µm menadione to more than halve cell growth rate and limit total protein content. We show that ribosome content on a total cell protein basis decreased in oxidatively stressed cells. However, overall protein synthesis rates on a ribosome abundance basis showed the resident ribosomes retained their function in oxidatively stressed cells. 15 N progressive labelling was used to calculate the rate of ribosome synthesis and degradation to track the fate of 62 r-proteins. The degradation rates and the synthesis rates of most r-proteins slowed following oxidative stress leading to an ageing population of ribosomes in stressed cells. However, there were exceptions to this trend; r-protein RPS14C doubled its degradation rate in both oxidative treatments. Overall, we show that ribosome abundance decreases and their age increases with oxidative stress in line with loss of cell growth rate and total cellular protein amount, but ribosome function of the ageing ribosomes appeared to be maintained concomittently with differences in the turnover rate and abundance of specific ribosomal proteins. Data are available via ProteomeXchange with identifier PXD012840.
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Affiliation(s)
- Karzan J Salih
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
- Pharmaceutical Chemistry Department, Medical and Applied Science College, Charmo University, 46023, Chamchamal-Sulaimani, Kurdistan Region, Iraq
| | - Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - Lei Li
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
- College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Brendan O'Leary
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - Ricarda Fenske
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - Josua Trösch
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
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20
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Huang S, Li L, Petereit J, Millar AH. Protein turnover rates in plant mitochondria. Mitochondrion 2020; 53:57-65. [DOI: 10.1016/j.mito.2020.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/22/2020] [Accepted: 04/29/2020] [Indexed: 02/06/2023]
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21
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Besse A, Brezavar D, Hanson J, Larson A, Bonnen PE. LONP1 de novo dominant mutation causes mitochondrial encephalopathy with loss of LONP1 chaperone activity and excessive LONP1 proteolytic activity. Mitochondrion 2020; 51:68-78. [PMID: 31923470 DOI: 10.1016/j.mito.2020.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 11/16/2019] [Accepted: 01/03/2020] [Indexed: 02/04/2023]
Abstract
LONP1 is an ATP-dependent protease and chaperone that plays multiple vital roles in mitochondria. LONP1 is essential for mitochondrial homeostasis due to its role in maintenance of the mitochondrial genome and its central role in regulating mitochondrial processes such as oxidative phosphorylation, mitophagy, and heme biosynthesis. Bi-allelic LONP1 mutations have been reported to cause a constellation of clinical presentations. We report a patient heterozygous for a de novo mutation in LONP1: c.901C>T,p.R301W presenting as a neonate with seizures, encephalopathy, pachygyria and microcephaly. Assays of respiratory chain activity in muscle showed complex II-III function at 8% of control. Functional studies in patient fibroblasts showed a signature of dysfunction that included significant decreases in known proteolytic targets of LONP1 (TFAM, PINK1, phospho-PDH E1α) as well as loss of mitochondrial ribosome subunits MRPL44 and MRPL11 with concomitant decreased activity and level of protein subunits of oxidative phosphorylation complexes I and IV. These results indicate excessive LONP1 proteolytic activity and a loss of LONP1 chaperone activity. Further, we demonstrate that the LONP1 N-terminal domain is involved in hexamer stability of LONP1 and that the ability to make conformational changes is necessary for LONP1 to regulate proper functioning of both its proteolytic and chaperone activities.
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Affiliation(s)
- Arnaud Besse
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Daniel Brezavar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Jennifer Hanson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Austin Larson
- University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, United States
| | - Penelope E Bonnen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States.
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22
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Ghifari AS, Huang S, Murcha MW. The peptidases involved in plant mitochondrial protein import. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6005-6018. [PMID: 31738432 DOI: 10.1093/jxb/erz365] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/08/2019] [Indexed: 05/17/2023]
Abstract
The endosymbiotic origin of the mitochondrion and the subsequent transfer of its genome to the host nucleus has resulted in intricate mechanisms of regulating mitochondrial biogenesis and protein content. The majority of mitochondrial proteins are nuclear encoded and synthesized in the cytosol, thus requiring specialized and dedicated machinery for the correct targeting import and sorting of its proteome. Most proteins targeted to the mitochondria utilize N-terminal targeting signals called presequences that are cleaved upon import. This cleavage is carried out by a variety of peptidases, generating free peptides that can be detrimental to organellar and cellular activity. Research over the last few decades has elucidated a range of mitochondrial peptidases that are involved in the initial removal of the targeting signal and its sequential degradation, allowing for the recovery of single amino acids. The significance of these processing pathways goes beyond presequence degradation after protein import, whereby the deletion of processing peptidases induces plant stress responses, compromises mitochondrial respiratory capability, and alters overall plant growth and development. Here, we review the multitude of plant mitochondrial peptidases that are known to be involved in protein import and processing of targeting signals to detail how their activities can affect organellar protein homeostasis and overall plant growth.
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Affiliation(s)
- Abi S Ghifari
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth WA, Australia
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Perth WA, Australia
| | - Shaobai Huang
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth WA, Australia
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Perth WA, Australia
| | - Monika W Murcha
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth WA, Australia
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Perth WA, Australia
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23
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Tsitsekian D, Daras G, Alatzas A, Templalexis D, Hatzopoulos P, Rigas S. Comprehensive analysis of Lon proteases in plants highlights independent gene duplication events. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2185-2197. [PMID: 30590727 PMCID: PMC6460959 DOI: 10.1093/jxb/ery440] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 11/28/2018] [Indexed: 05/10/2023]
Abstract
The degradation of damaged proteins is essential for cell viability. Lon is a highly conserved ATP-dependent serine-lysine protease that maintains proteostasis. We performed a comparative genome-wide analysis to determine the evolutionary history of Lon proteases. Prokaryotes and unicellular eukaryotes retained a single Lon copy, whereas multicellular eukaryotes acquired a peroxisomal copy, in addition to the mitochondrial gene, to sustain the evolution of higher order organ structures. Land plants developed small Lon gene families. Despite the Lon2 peroxisomal paralog, Lon genes triplicated in the Arabidopsis lineage through sequential evolutionary events including whole-genome and tandem duplications. The retention of Lon1, Lon4, and Lon3 triplicates relied on their differential and even contrasting expression patterns, distinct subcellular targeting mechanisms, and functional divergence. Lon1 seems similar to the pre-duplication ancestral gene unit, whereas the duplication of Lon3 and Lon4 is evolutionarily recent. In the wider context of plant evolution, papaya is the only genome with a single ancestral Lon1-type gene. The evolutionary trend among plants is to acquire Lon copies with ambiguous pre-sequences for dual-targeting to mitochondria and chloroplasts, and a substrate recognition domain that deviates from the ancestral Lon1 type. Lon genes constitute a paradigm of dynamic evolution contributing to understanding the functional fate of gene duplicates.
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Affiliation(s)
- Dikran Tsitsekian
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Gerasimos Daras
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Anastasios Alatzas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | | | | | - Stamatis Rigas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
- Correspondence:
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24
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Abstract
Gaussian process dynamical systems (GPDS) represent Bayesian nonparametric approaches to inference of nonlinear dynamical systems, and provide a principled framework for the learning of biological networks from multiple perturbed time series measurements of gene or protein expression. Such approaches are able to capture the full richness of complex ODE models, and can be scaled for inference in moderately large systems containing hundreds of genes. Related hierarchical approaches allow for inference from multiple datasets in which the underlying generative networks are assumed to have been rewired, either by context-dependent changes in network structure, evolutionary processes, or synthetic manipulation. These approaches can also be used to leverage experimentally determined network structures from one species into another where the network structure is unknown. Collectively, these methods provide a comprehensive and flexible platform for inference from a diverse range of data, with applications in systems and synthetic biology, as well as spatiotemporal modelling of embryo development. In this chapter we provide an overview of GPDS approaches and highlight their applications in the biological sciences, with accompanying tutorials available as a Jupyter notebook from https://github.com/cap76/GPDS .
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Affiliation(s)
| | - Iulia Gherman
- Warwick Integrative Synthetic Biology Centre, School of Engineering, University of Warwick, Coventry, UK
| | - Anastasiya Sybirna
- Wellcome/CRUK Gurdon Institute, University of Cambridge, Cambridge, UK
- Wellcome/MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
- Physiology, Development and Neuroscience Department, University of Cambridge, Cambridge, UK
| | - David L Wild
- Department of Statistics and Systems Biology Centre, University of Warwick, Coventry, UK
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25
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Lon protease inactivation in Drosophila causes unfolded protein stress and inhibition of mitochondrial translation. Cell Death Discov 2018; 4:51. [PMID: 30374414 PMCID: PMC6197249 DOI: 10.1038/s41420-018-0110-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial dysfunction is a frequent participant in common diseases and a principal suspect in aging. To combat mitochondrial dysfunction, eukaryotes have evolved a large repertoire of quality control mechanisms. One such mechanism involves the selective degradation of damaged or misfolded mitochondrial proteins by mitochondrial resident proteases, including proteases of the ATPase Associated with diverse cellular Activities (AAA+) family. The importance of the AAA+ family of mitochondrial proteases is exemplified by the fact that mutations that impair their functions cause a variety of human diseases, yet our knowledge of the cellular responses to their inactivation is limited. To address this matter, we created and characterized flies with complete or partial inactivation of the Drosophila matrix-localized AAA+ protease Lon. We found that a Lon null allele confers early larval lethality and that severely reducing Lon expression using RNAi results in shortened lifespan, locomotor impairment, and respiratory defects specific to respiratory chain complexes that contain mitochondrially encoded subunits. The respiratory chain defects of Lon knockdown (LonKD) flies appeared to result from severely reduced translation of mitochondrially encoded genes. This translational defect was not a consequence of reduced mitochondrial transcription, as evidenced by the fact that mitochondrial transcripts were elevated in abundance in LonKD flies. Rather, the translational defect of LonKD flies appeared to be derived from sequestration of mitochondrially encoded transcripts in highly dense ribonucleoparticles. The translational defect of LonKD flies was also accompanied by a substantial increase in unfolded mitochondrial proteins. Together, our findings suggest that the accumulation of unfolded mitochondrial proteins triggers a stress response that culminates in the inhibition of mitochondrial translation. Our work provides a foundation to explore the underlying molecular mechanisms.
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Li L, Aro EM, Millar AH. Mechanisms of Photodamage and Protein Turnover in Photoinhibition. TRENDS IN PLANT SCIENCE 2018; 23:667-676. [PMID: 29887276 DOI: 10.1016/j.tplants.2018.05.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 05/05/2018] [Accepted: 05/08/2018] [Indexed: 05/05/2023]
Abstract
Rapid protein degradation and replacement is an important response to photodamage and a means of photoprotection by recovering proteostasis. Protein turnover and translation efficiency studies have discovered fast turnover subunits in cytochrome b6f and the NAD(P)H dehydrogenase (NDH) complex, in addition to PSII subunit D1. Mutations of these complexes have been linked to enhanced photodamage at least partially via cyclic electron flow. Photodamage and photoprotection involving cytochrome b6f, NDH complex, cyclic electron flow, PSI, and nonphotochemical quenching proteins have been reported. Here, we propose that the rapid turnover of specific proteins in cytochrome b6f and the NDH complex need to be characterised and compared with the inhibition of PSII by excess excitation energy and PSI by excess electron flux to expand our understanding of photoinhibition mechanisms.
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Affiliation(s)
- Lei Li
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, 6009, Perth, WA, Australia
| | - Eva-Mari Aro
- Finnish Centre of Excellence in Molecular Biology of Primary Producers, Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014, Turku, Finland
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, 6009, Perth, WA, Australia.
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27
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Plant mitochondrial protein import: the ins and outs. Biochem J 2018; 475:2191-2208. [PMID: 30018142 DOI: 10.1042/bcj20170521] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 01/29/2023]
Abstract
The majority of the mitochondrial proteome, required to fulfil its diverse range of functions, is cytosolically synthesised and translocated via specialised machinery. The dedicated translocases, receptors, and associated proteins have been characterised in great detail in yeast over the last several decades, yet many of the mechanisms that regulate these processes in higher eukaryotes are still unknown. In this review, we highlight the current knowledge of mitochondrial protein import in plants. Despite the fact that the mechanisms of mitochondrial protein import have remained conserved across species, many unique features have arisen in plants to encompass the developmental, tissue-specific, and stress-responsive regulation in planta. An understanding of unique features and mechanisms in plants provides us with a unique insight into the regulation of mitochondrial biogenesis in higher eukaryotes.
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Broda M, Millar AH, Van Aken O. Mitophagy: A Mechanism for Plant Growth and Survival. TRENDS IN PLANT SCIENCE 2018; 23:434-450. [PMID: 29576328 DOI: 10.1016/j.tplants.2018.02.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 02/13/2018] [Accepted: 02/23/2018] [Indexed: 05/17/2023]
Abstract
Mitophagy is a conserved cellular process that is important for autophagic removal of damaged mitochondria to maintain a healthy mitochondrial population. Mitophagy also appears to occur in plants and has roles in development, stress response, senescence, and programmed cell death. However, many of the genes that control mitophagy in yeast and animal cells are absent from plants, and no plant proteins marking defunct mitochondria for autophagic degradation are yet known. New insights implicate general autophagy-related proteins in mitophagy, affecting the senescence of plant tissues. Mitophagy control and its importance for energy metabolism, survival, signaling, and cell death in plants are discussed. Furthermore, we suggest mitochondrial membrane proteins containing ATG8-interacting motifs, which might serve as mitophagy receptor proteins in plant mitochondria.
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Affiliation(s)
- Martyna Broda
- Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia, Australia
| | - A Harvey Millar
- Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia, Australia
| | - Olivier Van Aken
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden.
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29
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Kolodziejczak M, Skibior-Blaszczyk R, Janska H. m-AAA Complexes Are Not Crucial for the Survival of Arabidopsis Under Optimal Growth Conditions Despite Their Importance for Mitochondrial Translation. PLANT & CELL PHYSIOLOGY 2018; 59:1006-1016. [PMID: 29462458 DOI: 10.1093/pcp/pcy041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 02/09/2018] [Indexed: 05/17/2023]
Abstract
For optimal mitochondrial activity, the mitochondrial proteome must be properly maintained or altered in response to developmental and environmental stimuli. Based on studies of yeast and humans, one of the key players in this control are m-AAA proteases, mitochondrial inner membrane-bound ATP-dependent metalloenzymes. This study focuses on the importance of m-AAA proteases in plant mitochondria, providing their first experimentally proven physiological substrate. We found that the Arabidopsis m- AAA complexes composed of AtFTSH3 and/or AtFTSH10 are involved in the proteolytic maturation of ribosomal subunit L32. Consequently, in the double Arabidopsis ftsh3/10 mutant, mitoribosome biogenesis, mitochondrial translation and functionality of OXPHOS (oxidative phosphorylation) complexes are impaired. However, in contrast to their mammalian or yeast counterparts, plant m-AAA complexes are not critical for the survival of Arabidopsis under optimal conditions; ftsh3/10 plants are only slightly smaller in size at the early developmental stage compared with plants containing m-AAA complexes. Our data suggest that a lack of significant visible morphological alterations under optimal growth conditions involves mechanisms which rely on existing functional redundancy and induced functional compensation in Arabidopsis mitochondria.
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Affiliation(s)
- Marta Kolodziejczak
- Department of Cellular Molecular Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw 50-383, Poland
| | - Renata Skibior-Blaszczyk
- Department of Cellular Molecular Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw 50-383, Poland
| | - Hanna Janska
- Department of Cellular Molecular Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw 50-383, Poland
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Demir F, Niedermaier S, Villamor JG, Huesgen PF. Quantitative proteomics in plant protease substrate identification. THE NEW PHYTOLOGIST 2018; 218:936-943. [PMID: 28493421 DOI: 10.1111/nph.14587] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/07/2017] [Indexed: 05/17/2023]
Abstract
Contents Summary 936 I. Introduction 936 II. The quest for plant protease substrates - proteomics to the rescue? 937 III. Quantitative proteome comparison reveals candidate substrates 938 IV. Dynamic metabolic stable isotope labeling to measure protein turnover in vivo 938 V. Terminomics - large-scale identification of protease cleavage sites 939 VI. Substrate or not substrate, that is the question 940 VII. Concluding remarks 941 Acknowledgements 941 References 941 SUMMARY: Proteolysis is a central regulatory mechanism of protein homeostasis and protein function that affects all aspects of plant life. Higher plants encode for hundreds of proteases, but their physiological substrates and hence their molecular functions remain mostly unknown. Current quantitative mass spectrometry-based proteomics enables unbiased large-scale interrogation of the proteome and its modifications. Here we provide an overview of proteomics techniques that allow profiling of changes in protein abundance, measurement of proteome turnover rates, identification of protease cleavage sites in vivo and in vitro and determination of protease sequence specificity. We discuss how these techniques can help to reveal protease substrates and determine plant protease function, illustrated by recent studies on selected plant proteases.
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Affiliation(s)
- Fatih Demir
- ZEA-3 Analytics, Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich, Wilhelm-Johnen-Str., Jülich, 52425, Germany
| | - Stefan Niedermaier
- ZEA-3 Analytics, Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich, Wilhelm-Johnen-Str., Jülich, 52425, Germany
| | - Joji Grace Villamor
- ZEA-3 Analytics, Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich, Wilhelm-Johnen-Str., Jülich, 52425, Germany
| | - Pitter Florian Huesgen
- ZEA-3 Analytics, Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich, Wilhelm-Johnen-Str., Jülich, 52425, Germany
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Li L, Millar AH, Huang S. Mitochondrial Lon1 has a role in homeostasis of the mitochondrial ribosome and pentatricopeptide repeat proteins in plants. PLANT SIGNALING & BEHAVIOR 2017; 12:e1276686. [PMID: 28045582 PMCID: PMC5351720 DOI: 10.1080/15592324.2016.1276686] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 12/20/2016] [Indexed: 05/28/2023]
Abstract
Lon is a highly conserved protein family in eukaryotes and eubacteria and its members all contain both a chaperone and a proteolytic domain that are important for Lon function. Loss of mitochondrial Lon1 leads to deleterious phenotypes in yeast and plants, and causes developmental disorders and aging-related diseases in humans. In Arabidopsis, we have recently reported the multiple roles of Lon1 in mitochondrial protein homeostasis through an evaluation of changes in protein degradation rates in the absence of Lon1. 1 In this addendum, we extend our discussion to the roles of Lon1 in mitochondrial post-transcriptional regulation by considering the effects of its loss on ribosome proteins required for protein synthesis and mitochondrial PPR proteins required for RNA regulation.
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Affiliation(s)
- Lei Li
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
| | - A. Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
| | - Shaobai Huang
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
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