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Chandrasekaran U, Park S, Kim K, Byeon S, Han AR, Lee YS, Oh NH, Chung H, Choe H, Kim HS. Energy deprivation affects nitrogen assimilation and fatty acid biosynthesis leading to leaf chlorosis under waterlogging stress in the endangered Abies koreana. TREE PHYSIOLOGY 2024; 44:tpae055. [PMID: 38775218 DOI: 10.1093/treephys/tpae055] [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: 03/13/2024] [Revised: 05/15/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024]
Abstract
Energy deprivation triggers various physiological, biochemical and molecular changes in plants under abiotic stress. We investigated the oxidative damages in the high altitude grown conifer Korean fir (Abies koreana) exposed to waterlogging stress. Our experimental results showed that waterlogging stress led to leaf chlorosis, 35 days after treatment. A significant decrease in leaf fresh weight, chlorophyll and sugar content supported this phenotypic change. Biochemical analysis showed a significant increase in leaf proline, lipid peroxidase and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical content of waterlogged plants. To elucidate the molecular mechanisms, we conducted RNA-sequencing (RNA-seq) and de novo assembly. Using RNA-seq analysis approach and filtering (P < 0.05 and false discovery rate <0.001), we obtained 134 unigenes upregulated and 574 unigenes downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis placed the obtained differentially expressed unigenes in α-linoleic pathway, fatty acid degradation, glycosis, glycolipid metabolism and oligosaccharide biosynthesis process. Mapping of unigenes with Arabidopsis using basic local alignment search tool for nucleotides showed several critical genes in photosynthesis and carbon metabolism downregulated. Following this, we found the repression of multiple nitrogen (N) assimilation and nucleotide biosynthesis genes including purine metabolism. In addition, waterlogging stress reduced the levels of polyunsaturated fatty acids with a concomitant increase only in myristic acid. Together, our results indicate that the prolonged snowmelt may cause inability of A. koreana seedlings to lead the photosynthesis normally due to the lack of root intercellular oxygen and emphasizes a detrimental effect on the N metabolic pathway, compromising this endangered tree's ability to be fully functional under waterlogging stress.
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Affiliation(s)
- Umashankar Chandrasekaran
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
| | - Sanghee Park
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
| | - Kunhyo Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
| | - Siyeon Byeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ah Reum Han
- Division of Basic Research, National Institute of Ecology, 1210 Geumgang-ro, Seocheon-gun 33657, Republic of Korea
| | - Young-Sang Lee
- Division of Basic Research, National Institute of Ecology, 1210 Geumgang-ro, Seocheon-gun 33657, Republic of Korea
| | - Neung-Hwan Oh
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, 1 Gwanak-gu, Seoul 08826, Republic of Korea
- Environmental Planning Institute, Seoul National University, 1 Gwanak-gu, Seoul 08826, Republic of Korea
| | - Haegeun Chung
- Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hyeyeong Choe
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hyun Seok Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
- Interdisciplinary Program in Agricultural and Forest Meteorology, Seoul National University College of Agriculture and Life Sciences, 1 Gwanak-gu, Seoul 08826, Republic of Korea
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2
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An H, Ke X, Li L, Liu Y, Yuan S, Wang Q, Hou X, Zhao J. ALBINO EMBRYO AND SEEDLING is required for RNA splicing and chloroplast homeostasis in Arabidopsis. PLANT PHYSIOLOGY 2023; 193:483-501. [PMID: 37311175 DOI: 10.1093/plphys/kiad341] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 05/03/2023] [Accepted: 05/07/2023] [Indexed: 06/15/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins form a large protein family and have diverse functions in plant development. Here, we identified an ALBINO EMBRYO AND SEEDLING (AES) gene that encodes a P-type PPR protein expressed in various tissues, especially the young leaves of Arabidopsis (Arabidopsis thaliana). Its null mutant aes exhibited a collapsed chloroplast membrane system, reduced pigment content and photosynthetic activity, decreased transcript levels of PEP (plastid-encoded polymerase)-dependent chloroplast genes, and defective RNA splicing. Further work revealed that AES could directly bind to psbB-psbT, psbH-petB, rps8-rpl36, clpP, ycf3, and ndhA in vivo and in vitro and that the splicing efficiencies of these genes and the expression levels of ycf3, ndhA, and cis-tron psbB-psbT-psbH-petB-petD decreased dramatically, leading to defective PSI, PSII, and Cyt b6f in aes. Moreover, AES could be transported into the chloroplast stroma via the TOC-TIC channel with the assistance of Tic110 and cpSRP54 and may recruit HCF244, SOT1, and CAF1 to participate in the target RNA process. These findings suggested that AES is an essential protein for the assembly of photosynthetic complexes, providing insights into the splicing of psbB operon (psbB-psbT-psbH-petB-petD), ycf3, and ndhA, as well as maintaining chloroplast homeostasis.
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Affiliation(s)
- Hongqiang An
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Xiaolong Ke
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Lu Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Yantong Liu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Sihui Yuan
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Qiuyu Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Xin Hou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
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van Wijk KJ, Leppert T, Sun Q, Boguraev SS, Sun Z, Mendoza L, Deutsch EW. The Arabidopsis PeptideAtlas: Harnessing worldwide proteomics data to create a comprehensive community proteomics resource. THE PLANT CELL 2021; 33:3421-3453. [PMID: 34411258 PMCID: PMC8566204 DOI: 10.1093/plcell/koab211] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/13/2021] [Indexed: 05/02/2023]
Abstract
We developed a resource, the Arabidopsis PeptideAtlas (www.peptideatlas.org/builds/arabidopsis/), to solve central questions about the Arabidopsis thaliana proteome, such as the significance of protein splice forms and post-translational modifications (PTMs), or simply to obtain reliable information about specific proteins. PeptideAtlas is based on published mass spectrometry (MS) data collected through ProteomeXchange and reanalyzed through a uniform processing and metadata annotation pipeline. All matched MS-derived peptide data are linked to spectral, technical, and biological metadata. Nearly 40 million out of ∼143 million MS/MS (tandem MS) spectra were matched to the reference genome Araport11, identifying ∼0.5 million unique peptides and 17,858 uniquely identified proteins (only isoform per gene) at the highest confidence level (false discovery rate 0.0004; 2 non-nested peptides ≥9 amino acid each), assigned canonical proteins, and 3,543 lower-confidence proteins. Physicochemical protein properties were evaluated for targeted identification of unobserved proteins. Additional proteins and isoforms currently not in Araport11 were identified that were generated from pseudogenes, alternative start, stops, and/or splice variants, and small Open Reading Frames; these features should be considered when updating the Arabidopsis genome. Phosphorylation can be inspected through a sophisticated PTM viewer. PeptideAtlas is integrated with community resources including TAIR, tracks in JBrowse, PPDB, and UniProtKB. Subsequent PeptideAtlas builds will incorporate millions more MS/MS data.
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Affiliation(s)
- Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, USA
- Authors for correspondence: (K.J.V.W.), (E.W.D.)
| | - Tami Leppert
- Institute for Systems Biology (ISB), Seattle, Washington 98109, USA
| | - Qi Sun
- Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, USA
| | - Sascha S Boguraev
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, USA
| | - Zhi Sun
- Institute for Systems Biology (ISB), Seattle, Washington 98109, USA
| | - Luis Mendoza
- Institute for Systems Biology (ISB), Seattle, Washington 98109, USA
| | - Eric W Deutsch
- Institute for Systems Biology (ISB), Seattle, Washington 98109, USA
- Authors for correspondence: (K.J.V.W.), (E.W.D.)
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Xu X, Legay S, Sergeant K, Zorzan S, Leclercq CC, Charton S, Giarola V, Liu X, Challabathula D, Renaut J, Hausman JF, Bartels D, Guerriero G. Molecular insights into plant desiccation tolerance: transcriptomics, proteomics and targeted metabolite profiling in Craterostigma plantagineum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:377-398. [PMID: 33901322 PMCID: PMC8453721 DOI: 10.1111/tpj.15294] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 04/05/2021] [Accepted: 04/19/2021] [Indexed: 05/31/2023]
Abstract
The resurrection plant Craterostigma plantagineum possesses an extraordinary capacity to survive long-term desiccation. To enhance our understanding of this phenomenon, complementary transcriptome, soluble proteome and targeted metabolite profiling was carried out on leaves collected from different stages during a dehydration and rehydration cycle. A total of 7348 contigs, 611 proteins and 39 metabolites were differentially abundant across the different sampling points. Dynamic changes in transcript, protein and metabolite levels revealed a unique signature characterizing each stage. An overall low correlation between transcript and protein abundance suggests a prominent role for post-transcriptional modification in metabolic reprogramming to prepare plants for desiccation and recovery. The integrative analysis of all three data sets was performed with an emphasis on photosynthesis, photorespiration, energy metabolism and amino acid metabolism. The results revealed a set of precise changes that modulate primary metabolism to confer plasticity to metabolic pathways, thus optimizing plant performance under stress. The maintenance of cyclic electron flow and photorespiration, and the switch from C3 to crassulacean acid metabolism photosynthesis, may contribute to partially sustain photosynthesis and minimize oxidative damage during dehydration. Transcripts with a delayed translation, ATP-independent bypasses, alternative respiratory pathway and 4-aminobutyric acid shunt may all play a role in energy management, together conferring bioenergetic advantages to meet energy demands upon rehydration. This study provides a high-resolution map of the changes occurring in primary metabolism during dehydration and rehydration and enriches our understanding of the molecular mechanisms underpinning plant desiccation tolerance. The data sets provided here will ultimately inspire biotechnological strategies for drought tolerance improvement in crops.
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Affiliation(s)
- Xuan Xu
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Sylvain Legay
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Kjell Sergeant
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Simone Zorzan
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Céline C Leclercq
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Sophie Charton
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Valentino Giarola
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, Bonn, D-53115, Germany
| | - Xun Liu
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, Bonn, D-53115, Germany
| | - Dinakar Challabathula
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, Bonn, D-53115, Germany
| | - Jenny Renaut
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Jean-Francois Hausman
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
| | - Dorothea Bartels
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, Bonn, D-53115, Germany
| | - Gea Guerriero
- GreenTech Innovation Centre, Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, L-4362, Luxembourg
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Liu X, Xu Z, Yang Y, Cao P, Cheng H, Zhou H. Plastid caseinolytic protease OsClpR1 regulates chloroplast development and chloroplast RNA editing in rice. RICE (NEW YORK, N.Y.) 2021; 14:45. [PMID: 34018050 PMCID: PMC8137786 DOI: 10.1186/s12284-021-00489-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Plant plastidic caseinolytic protease (Clp) is a central part of the plastid protease network and consists of multiple subunits. The molecular functions of many Clps in plants, especially in crops, are not well known. RESULTS In this study, we identified an albino lethal mutant al3 in rice, which produces albino leaves and dies at the seedling stage. Molecular cloning revealed that AL3 encodes a plastid caseinolytic protease, OsClpR1, homologous to Arabidopsis ClpR1 and is targeted to the chloroplast. Compared with the wild type, chloroplast structure in the al3 mutant was poorly developed. OsClpR1 was constitutively expressed in all rice tissues, especially in young leaves. The OsClpR1 mutation affected the transcript levels of chlorophyll biosynthesis and chloroplast development-related genes. The RNA editing efficiency of three chloroplast genes (rpl2, ndhB, ndhA) was remarkably reduced in al3. Using a yeast two-hybrid screen, we found that OsClpR1 interacted with OsClpP4, OsClpP5, OsClpP2, and OsClpS1. CONCLUSIONS Collectively, our results provide novel insights into the function of Clps in rice.
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Affiliation(s)
- Xi Liu
- Key Laboratory of Eco-Agricultural Biotechnology around Hongze Lake, Regional Cooperative Innovation Center for Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China.
| | - Ziyi Xu
- Key Laboratory of Eco-Agricultural Biotechnology around Hongze Lake, Regional Cooperative Innovation Center for Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Yanrong Yang
- Key Laboratory of Eco-Agricultural Biotechnology around Hongze Lake, Regional Cooperative Innovation Center for Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Penghui Cao
- Suzhou Academy of Agricultural Sciences, Suzhou, 215155, China
| | - Hang Cheng
- Key Laboratory of Eco-Agricultural Biotechnology around Hongze Lake, Regional Cooperative Innovation Center for Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Haiying Zhou
- Key Laboratory of Eco-Agricultural Biotechnology around Hongze Lake, Regional Cooperative Innovation Center for Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
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Zhao X, Zhang T, Feng H, Qiu T, Li Z, Yang J, Peng YL, Zhao W. OsNBL1, a Multi-Organelle Localized Protein, Plays Essential Roles in Rice Senescence, Disease Resistance, and Salt Tolerance. RICE (NEW YORK, N.Y.) 2021; 14:10. [PMID: 33423130 PMCID: PMC7797018 DOI: 10.1186/s12284-020-00450-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 12/26/2020] [Indexed: 06/01/2023]
Abstract
BACKGROUND Plant senescence is a complicated process involving multiple regulations, such as temperature, light, reactive oxygen species (ROS), endogenous hormone levels, and diseases. Although many such genes have been characterized to understand the process of leaf senescence, there still remain many unknowns, and many more genes need to be characterized. RESULTS We identified a rice mutant nbl1 with a premature leaf senescence phenotype. The causative gene, OsNBL1, encodes a small protein with 94 amino acids, which is conserved in monocot, as well as dicot plants. Disruption of OsNBL1 resulted in accelerated dark-induced leaf senescence, accompanied by a reduction in chlorophyll content and up-regulation of several senescence-associated genes. Notably, the nbl1 mutant was more susceptible to rice blast and bacterial blight but more tolerant to sodium chloride. Several salt-induced genes, including HAK1, HAK5, and three SNAC genes, were also up-regulated in the nbl1 mutant. Additionally, the nbl1 mutant was more sensitive to salicylic acid. Plants overexpressing OsNBL1 showed delayed dark-induced senescence, consistent with a higher chlorophyll content compared to wild-type plants. However, the overexpression plants were indistinguishable from the wild-types for resistance to the rice blast disease. OsNBL1 is a multi-organelle localized protein and interacts with OsClpP6, which is associated with senescence. CONCLUSIONS We described a novel leaf senescence mutant nbl1 in rice. It is showed that OsNBL1, a multi-organelle localized protein which interacts with a plastidic caseinolytic protease OsClpP6, is essential for controlling leaf senescence, disease resistance, and salt tolerance.
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Affiliation(s)
- Xiaosheng Zhao
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
- Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/ College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Tianbo Zhang
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Huijing Feng
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Tiancheng Qiu
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Zichao Li
- Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/ College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Jun Yang
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - You-Liang Peng
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Wensheng Zhao
- State Key Laboratory of Agrobiotechnology, MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China.
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Recombinant expression, purification and SAXS analysis of Arabidopsis thaliana ClpC1. Int J Biol Macromol 2020; 167:1273-1280. [PMID: 33189753 DOI: 10.1016/j.ijbiomac.2020.11.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 11/23/2022]
Abstract
Caseinolytic protease-associated chaperones (Clp chaperones) are HSP100 proteins belonging to the family of ATPases having diverse cellular functions, and they occur in various organisms ranging from bacteria to plants and mammals. Most Clp chaperones have a hexameric organization and associate with tetradecameric Clp proteases to recognize and unfold protein substrates that get degraded within the cellular milieu. Vascular plants have a diverse family of Clp chaperones compared to other organisms; wherein, the chloroplasts of Arabidopsis thaliana alone contain four distinct Clp chaperones, such as ClpC1, ClpC2, ClpD, and ClpB3. The paralogs AtClpC1 and AtClpC2 are more than 90% identical, though the extent of functional overlap between the two is not clear. Moreover, in vitro characterization reports are available only for AtClpC2, as AtClpC1 could not be expressed in recombinant form in the past. Herein, using a bacterial expression system, we have successfully expressed and purified AtClpC1 with a short N-terminal truncation, employing a three-step chromatographic purification strategy. We show that AtClpC1 exists as a hexamer in the presence of ATP and MgCl2, as known for other functional Clp chaperones. Further, our SAXS analyses provide a low-resolution envelope structure for the hexameric AtClpC1, which very well fits a ClpC hexamer model.
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