1
|
Zheng A, Tian C, Zhou C, Yang N, Wen S, Hu X, Zhang Z, Fang J, Lai Z, Guo Y. Genome-wide identification and characterization of CsHSP60 gene family associated with heat and drought responses in tea plants (Camellia sinensis). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2025; 222:109758. [PMID: 40073741 DOI: 10.1016/j.plaphy.2025.109758] [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: 06/27/2024] [Revised: 02/21/2025] [Accepted: 03/05/2025] [Indexed: 03/14/2025]
Abstract
Heat and drought are the stressors with significant adverse impacts on the yield stability of tea plants. The heat shock proteins 60 (HSP60s) play important roles in protecting plants under heat stress. However, the mechanism of HSP60s under heat and drought stresses remains unclear. Here, we identified 19 CsHSP60s (namely CsHSP60-1 to CsHSP60-19) in tea plants and classified them into three groups based on phylogenetic analysis. In addition, studies on gene duplication events during the evolutionary process demonstrated that CsHSP60 members were subjected to purify selection. Analysis of cis-acting elements revealed the presence of numerous stress and hormone-responsive elements within the promoter regions of CsHSP60s. Real-time quantitative fluorescent PCR (qRT-PCR) analyses demonstrated that CsHSP60s rapidly responded to heat and combined heat and drought stress while exhibiting a delayed response to drought stress. The inhibition of eight CsHSP60 genes via antisense oligodeoxynucleotide (AsODN) resulted in more severe damage and ROS accumulation. Specifically, CsHSP60-9, CsHSP60-16, and CsHSP60-19 exhibited notable reductions in Fv/Fm values and displayed increased accumulation of H2O2 and O2·-. These observations indicated a potential role for CsHSP60 in mitigating ROS accumulation under stress conditions, thereby enhancing tea plants' resilience to heat and drought stresses. Using a yeast two-hybrid (Y2H) assay, we identified that CsHSP60-2 and CsHSP60-16 physically interact with CsCPN10-4 and CsCPN10-5, respectively. These interactions suggest a cooperative chaperone activity between CsHSP60 and CsCPN10 in response to combined heat and drought stress. These findings lay a foundation for further understanding the involvement of HSP60s in the tolerance mechanisms to compound heat and drought stresses.
Collapse
Affiliation(s)
- Anru Zheng
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Caiyun Tian
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Chengzhe Zhou
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Niannian Yang
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shengjing Wen
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiaowen Hu
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhendong Zhang
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jiaxin Fang
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhongxiong Lai
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yuqiong Guo
- Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Tea Green Cultivation and Processing Collaborative Innovation Center, Anxi County, Quanzhou, 362400, China; Tea Industry Research Institute, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
| |
Collapse
|
2
|
Ries F, Weil HL, Herkt C, Mühlhaus T, Sommer F, Schroda M, Willmund F. Competition co-immunoprecipitation reveals the interactors of the chloroplast CPN60 chaperonin machinery. PLANT, CELL & ENVIRONMENT 2023; 46:3371-3391. [PMID: 37606545 DOI: 10.1111/pce.14697] [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: 03/27/2023] [Revised: 07/28/2023] [Accepted: 08/11/2023] [Indexed: 08/23/2023]
Abstract
The functionality of all metabolic processes in chloroplasts depends on a balanced integration of nuclear- and chloroplast-encoded polypeptides into the plastid's proteome. The chloroplast chaperonin machinery is an essential player in chloroplast protein folding under ambient and stressful conditions, with a more intricate structure and subunit composition compared to the orthologous GroEL/ES chaperonin of Escherichia coli. However, its exact role in chloroplasts remains obscure, mainly because of very limited knowledge about the interactors. We employed the competition immunoprecipitation method for the identification of the chaperonin's interactors in Chlamydomonas reinhardtii. Co-immunoprecipitation of the target complex in the presence of increasing amounts of isotope-labelled competitor epitope and subsequent mass spectrometry analysis specifically allowed to distinguish true interactors from unspecifically co-precipitated proteins. Besides known substrates such as RbcL and the expected complex partners, we revealed numerous new interactors with high confidence. Proteins that qualify as putative substrate proteins differ from bulk chloroplast proteins by a higher content of beta-sheets, lower alpha-helical conformation and increased aggregation propensity. Immunoprecipitations targeted against a subunit of the co-chaperonin lid revealed the ClpP protease as a specific partner complex, pointing to a close collaboration of these machineries to maintain protein homeostasis in the chloroplast.
Collapse
Affiliation(s)
- Fabian Ries
- Molecular Genetics of Eukaryotes, University of Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Heinrich Lukas Weil
- Computational Systems Biology, University of Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Claudia Herkt
- Molecular Genetics of Eukaryotes, University of Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Timo Mühlhaus
- Computational Systems Biology, University of Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Frederik Sommer
- Molecular Biotechnology and Systems Biology, University of Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, University of Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Felix Willmund
- Molecular Genetics of Eukaryotes, University of Kaiserslautern-Landau, Kaiserslautern, Germany
- Plant Physiology/Synmikro, University of Marburg, Marburg, Germany
| |
Collapse
|
3
|
A temporal gradient of cytonuclear coordination of chaperonins and chaperones during RuBisCo biogenesis in allopolyploid plants. Proc Natl Acad Sci U S A 2022; 119:e2200106119. [PMID: 35969751 PMCID: PMC9407610 DOI: 10.1073/pnas.2200106119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo), consisting of subunits encoded by nuclear and cytoplasmic genes, is a model for cytonuclear evolution in plant allopolyploids. To date, coordinated cytonuclear evolutionary responses of auxiliary cofactors involved in RuBisCo biogenesis remain unexplored. This study characterized and compared genomic and transcriptional cytonuclear coevolutionary responses of chaperonin/chaperones in RuBisCo folding and assembly processes across different allopolyploids. We discovered significant cytonuclear evolutionary responses in folding cofactors, with diminishing or attenuated responses later during assembly. Our results have general significance for understanding the unrecognized cytonuclear evolution of chaperonin/chaperone genes, structural and functional features of intermediate complexes, and the functioning stage of the Raf2 cofactor. Generally, the results reveal a hitherto unexplored dimension of allopolyploidy in plants. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo) has long been studied from many perspectives. As a multisubunit (large subunits [LSUs] and small subunits[SSUs]) protein encoded by genes residing in the chloroplast (rbcL) and nuclear (rbcS) genomes, RuBisCo also is a model for cytonuclear coevolution following allopolyploid speciation in plants. Here, we studied the genomic and transcriptional cytonuclear coordination of auxiliary chaperonin and chaperones that facilitate RuBisCo biogenesis across multiple natural and artificially synthesized plant allopolyploids. We found similar genomic and transcriptional cytonuclear responses, including respective paternal-to-maternal conversions and maternal homeologous biased expression, in chaperonin/chaperon-assisted folding and assembly of RuBisCo in different allopolyploids. One observation is about the temporally attenuated genomic and transcriptional cytonuclear evolutionary responses during early folding and later assembly process of RuBisCo biogenesis, which were established by long-term evolution and immediate onset of allopolyploidy, respectively. Our study not only points to the potential widespread and hitherto unrecognized features of cytonuclear evolution but also bears implications for the structural interaction interface between LSU and Cpn60 chaperonin and the functioning stage of the Raf2 chaperone.
Collapse
|
4
|
Wang N, Wang Y, Zhao Q, Zhang X, Peng C, Zhang W, Liu Y, Vallon O, Schroda M, Cong Y, Liu C. The cryo-EM structure of the chloroplast ClpP complex. NATURE PLANTS 2021; 7:1505-1515. [PMID: 34782772 DOI: 10.1038/s41477-021-01020-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Protein homoeostasis in plastids is strategically regulated by the protein quality control system involving multiple chaperones and proteases, among them the Clp protease. Here, we determined the structure of the chloroplast ClpP complex from Chlamydomonas reinhardtii by cryo-electron microscopy. ClpP contains two heptameric catalytic rings without any symmetry. The top ring contains one ClpR6, three ClpP4 and three ClpP5 subunits while the bottom ring is composed of three ClpP1C subunits and one each of the ClpR1-4 subunits. ClpR3, ClpR4 and ClpT4 subunits connect the two rings and stabilize the complex. The chloroplast Cpn11/20/23 co-chaperonin, a co-factor of Cpn60, forms a cap on the top of ClpP by protruding mobile loops into hydrophobic clefts at the surface of the top ring. The co-chaperonin repressed ClpP proteolytic activity in vitro. By regulating Cpn60 chaperone and ClpP protease activity, the co-chaperonin may play a role in coordinating protein folding and degradation in the chloroplast.
Collapse
Affiliation(s)
- Ning Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yifan Wang
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, China
| | - Qian Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Xiang Zhang
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, China
| | - Chao Peng
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, CAS, Shanghai, China
| | - Wenjuan Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yanan Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Olivier Vallon
- Institut de Biologie Physico-Chimique, Sorbonne Université, Paris, France
| | - Michael Schroda
- Molecular Biotechnology & Systems Biology, TU Kaiserslautern, Kaiserslautern, Germany
| | - Yao Cong
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, China.
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
5
|
Nagaraju M, Kumar A, Jalaja N, Rao DM, Kishor PBK. Functional Exploration of Chaperonin (HSP60/10) Family Genes and their Abiotic Stress-induced Expression Patterns in Sorghum bicolor. Curr Genomics 2021; 22:137-152. [PMID: 34220300 PMCID: PMC8188580 DOI: 10.2174/1389202922666210324154336] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 01/05/2021] [Accepted: 01/22/2021] [Indexed: 11/30/2022] Open
Abstract
Background Sorghum, the C4 dry-land cereal, important for food, fodder, feed and fuel, is a model crop for abiotic stress tolerance with smaller genome size, genetic diversity, and bio-energy traits. The heat shock proteins/chaperonin 60s (HSP60/Cpn60s) assist the plastid proteins, and participate in the folding and aggregation of proteins. However, the functions of HSP60s in abiotic stress tolerance in Sorghum remain unclear. Methods Genome-wide screening and in silico characterization of SbHSP60s were carried out along with tissue and stress-specific expression analysis. Results A total of 36 HSP60 genes were identified in Sorghum bicolor. They were subdivided into 2 groups, the HSP60 and HSP10 co-chaperonins encoded by 30 and 6 genes, respectively. The genes are distributed on all the chromosomes, chromosome 1 being the hot spot with 9 genes. All the HSP60s were found hydrophilic and highly unstable. The HSP60 genes showed a large number of introns, the majority of them with more than 10. Among the 12 paralogs, only 1 was tandem and the remaining 11 segmental, indicating their role in the expansion of SbHSP60s. Majority of the SbHSP60 genes expressed uniformly in leaf while a moderate expression was observed in the root tissues, with the highest expression displayed by SbHSP60-1. From expression analysis, SbHSP60-3 for drought, SbHSP60-9 for salt, SbHSP60-9 and 24 for heat and SbHSP60-3, 9 and SbHSP10-2 have been found implicated for cold stress tolerance and appeared as the key regulatory genes. Conclusion This work paves the way for the utilization of chaperonin family genes for achieving abiotic stress tolerance in plants.
Collapse
Affiliation(s)
- M Nagaraju
- Department of Genetics, Osmania University, Hyderabad 500 007, India.,Biochemistry Division, National Institute of Nutrition (ICMR), Hyderabad 500 007, India
| | - Anuj Kumar
- Advance Center for Computational & Applied Biotechnology, Uttarakhand Council for Biotechnology (UCB), Silk Park, Prem Nagar, Dehradun 248 007, India
| | - N Jalaja
- Department of Biotechnology, Vignan's Foundation for Science, Technology and Research, Vadlamudi, Guntur 522 213, Andhra Pradesh, India
| | - D Manohar Rao
- Department of Genetics, Osmania University, Hyderabad 500 007, India
| | - P B Kavi Kishor
- Department of Biotechnology, Vignan's Foundation for Science, Technology and Research, Vadlamudi, Guntur 522 213, Andhra Pradesh, India
| |
Collapse
|
6
|
Ye J, Chen W, Feng L, Liu G, Wang Y, Li H, Ye Z, Zhang Y. The chaperonin 60 protein SlCpn60α1 modulates photosynthesis and photorespiration in tomato. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7224-7240. [PMID: 32915204 DOI: 10.1093/jxb/eraa418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/08/2020] [Indexed: 06/11/2023]
Abstract
Photosynthesis, an indispensable biological process of plants, produces organic substances for plant growth, during which photorespiration occurs to oxidize carbohydrates to achieve homeostasis. Although the molecular mechanism underlying photosynthesis and photorespiration has been widely explored, the crosstalk between the two processes remains largely unknown. In this study, we isolated and characterized a T-DNA insertion mutant of tomato (Solanum lycopersicum) named yellow leaf (yl) with yellowish leaves, retarded growth, and chloroplast collapse that hampered both photosynthesis and photorespiration. Genetic and expression analyses demonstrated that the phenotype of yl was caused by a loss-of-function mutation resulting from a single-copy T-DNA insertion in chaperonin 60α1 (SlCPN60α1). SlCPN60α1 showed high expression levels in leaves and was located in both chloroplasts and mitochondria. Silencing of SlCPN60α1using virus-induced gene silencing and RNA interference mimicked the phenotype of yl. Results of two-dimensional electrophoresis and yeast two-hybrid assays suggest that SlCPN60α1 potentially interacts with proteins that are involved in chlorophyll synthesis, photosynthetic electron transport, and the Calvin cycle, and further affect photosynthesis. Moreover, SlCPN60α1 directly interacted with serine hydroxymethyltransferase (SlSHMT1) in mitochondria, thereby regulating photorespiration in tomato. This study outlines the importance of SlCPN60α1 for both photosynthesis and photorespiration, and provides molecular insights towards plant genetic improvement.
Collapse
Affiliation(s)
- Jie Ye
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA
| | - Weifang Chen
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Longwei Feng
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Genzhong Liu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Ying Wang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Hanxia Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Yuyang Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
7
|
Tiwari LD, Grover A. Cpn60β4 protein regulates growth and developmental cycling and has bearing on flowering time in Arabidopsis thaliana plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 286:78-88. [PMID: 31300145 DOI: 10.1016/j.plantsci.2019.05.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/25/2019] [Accepted: 05/28/2019] [Indexed: 06/10/2023]
Abstract
Chloroplastic Cpn60 proteins are type I chaperonins comprising of Cpn60α and Cpn60β subunits. Arabidopsis genome contains six entries in Cpn60 family, out of which two are for Cpn60α subunit and four for Cpn60β subunit. We noted that the cpn60β4 knockout mutant plants (T-DNA insertion salk_064887 line) differed from the wild type Col-0 plants in the developmental programming. cpn60β4 mutant plants showed early seed germination. Radical emergence, hypocotyl emergence and cotyledons opening were faster in cpn60β4 mutant plants than WT. Importantly, cpn60β4 mutant plants showed early-flowering phenotype. The number of flowers and siliques as well as weight of the seeds were higher in cpn60β4 mutant plants as compared to Col-0 plants. These effects were reverted to wild type like growth and developmental patterns when genomic fragment of Arabidopsis encompassing Cpn60β4 gene was complemented in the mutant background. The overexpression of Cpn60β4 gene using CaMV35 promoter in wild type background (OE-Cpn60β4) delayed the floral transition as against wild type plants. The plastid division were affected in cpn60β4 mutant plants compared to Col-0. The results of this study suggest that Cpn60β4 plays important role(s) in chloroplast development and is a key factor in plant growth, development and flowering in Arabidopsis.
Collapse
Affiliation(s)
- Lalit Dev Tiwari
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India
| | - Anil Grover
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India.
| |
Collapse
|
8
|
Zhao Q, Zhang X, Sommer F, Ta N, Wang N, Schroda M, Cong Y, Liu C. Hetero-oligomeric CPN60 resembles highly symmetric group-I chaperonin structure revealed by Cryo-EM. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:798-812. [PMID: 30735603 DOI: 10.1111/tpj.14273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/07/2019] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
The chloroplast chaperonin system is indispensable for the biogenesis of Rubisco, the key enzyme in photosynthesis. Using Chlamydomonas reinhardtii as a model system, we found that in vivo the chloroplast chaperonin consists of CPN60α, CPN60β1 and CPN60β2 and the co-chaperonin of the three subunits CPN20, CPN11 and CPN23. In Escherichia coli, CPN20 homo-oligomers and all possible other chloroplast co-chaperonin hetero-oligomers are functional, but only that consisting of CPN11/20/23-CPN60αβ1β2 can fully replace GroES/GroEL under stringent stress conditions. Endogenous CPN60 was purified and its stoichiometry was determined to be 6:2:6 for CPN60α:CPN60β1:CPN60β2. The cryo-EM structures of endogenous CPN60αβ1β2/ADP and CPN60αβ1β2/co-chaperonin/ADP were solved at resolutions of 4.06 and 3.82 Å, respectively. In both hetero-oligomeric complexes the chaperonin subunits within each ring are highly symmetric. Through hetero-oligomerization, the chloroplast co-chaperonin CPN11/20/23 forms seven GroES-like domains, which symmetrically interact with CPN60αβ1β2. Our structure also reveals an uneven distribution of roof-forming domains in the dome-shaped CPN11/20/23 co-chaperonin and potentially diversified surface properties in the folding cavity of the CPN60αβ1β2 chaperonin that might enable the chloroplast chaperonin system to assist in the folding of specific substrates.
Collapse
Affiliation(s)
- Qian Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiang Zhang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 201210, China
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Frederik Sommer
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Na Ta
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Ning Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Erwin-Schroedinger Str. 70, 67663, Kaiserslautern, Germany
| | - Yao Cong
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 201210, China
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| |
Collapse
|
9
|
Nováková S, Danchenko M, Skultety L, Fialová I, Lešková A, Beke G, Flores-Ramírez G, Glasa M. Photosynthetic and Stress Responsive Proteins Are Altered More Effectively in Nicotiana benthamiana Infected with Plum pox virus Aggressive PPV-CR versus Mild PPV-C Cherry-Adapted Isolates. J Proteome Res 2018; 17:3114-3127. [PMID: 30084641 DOI: 10.1021/acs.jproteome.8b00230] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Plum pox virus (PPV, family Potyviridae) is one of the most important viral pathogens of Prunus spp. causing considerable damage to stone-fruit industry worldwide. Among the PPV strains identified so far, only PPV-C, PPV-CR, and PPV-CV are able to infect cherries under natural conditions. Herein, we evaluated the pathogenic potential of two viral isolates in herbaceous host Nicotiana benthamiana. Significantly higher accumulation of PPV capsid protein in tobacco leaves infected with PPV-CR (RU-30sc isolate) was detected in contrast to PPV-C (BY-101 isolate). This result correlated well with the symptoms observed in the infected plants. To further explore the host response upon viral infection at the molecular level, a comprehensive proteomic profiling was performed. Using reverse-phase ultra-high-performance liquid chromatography followed by label-free mass spectrometry quantification, we identified 38 unique plant proteins as significantly altered due to the infection. Notably, the abundances of photosynthesis-related proteins, mainly from the Calvin-Benson cycle, were found more aggressively affected in plants infected with PPV-CR isolate than those of PPV-C. This observation was accompanied by a significant reduction in the amount of photosynthetic pigments extracted from the leaves of PPV-CR infected plants. Shifts in the abundance of proteins that are involved in stimulation of photosynthetic capacity, modification of amino acid, and carbohydrate metabolism may affect plant growth and initiate energy formation via gluconeogenesis in PPV infected N. benthamiana. Furthermore, we suggest that the higher accumulation of H2O2 in PPV-CR infected leaves plays a crucial role in plant defense and development by activating the glutathione synthesis.
Collapse
Affiliation(s)
- Slavomíra Nováková
- Biomedical Research Center, Institute of Virology , Slovak Academy of Sciences , Dubravska cesta 9 , 845 05 Bratislava , Slovak Republic
| | - Maksym Danchenko
- Biomedical Research Center, Institute of Virology , Slovak Academy of Sciences , Dubravska cesta 9 , 845 05 Bratislava , Slovak Republic
| | - Ludovit Skultety
- Biomedical Research Center, Institute of Virology , Slovak Academy of Sciences , Dubravska cesta 9 , 845 05 Bratislava , Slovak Republic
- Institute of Microbiology , The Czech Academy of Sciences , Videnska 1083 , 142 20 Prague , Czech Republic
| | - Ivana Fialová
- Plant Science and Biodiversity Center, Institute of Botany , Slovak Academy of Sciences , Dubravska cesta 9 , 845 23 Bratislava , Slovak Republic
| | - Alexandra Lešková
- Plant Science and Biodiversity Center, Institute of Botany , Slovak Academy of Sciences , Dubravska cesta 9 , 845 23 Bratislava , Slovak Republic
| | - Gábor Beke
- Institute of Molecular Biology , Slovak Academy of Sciences , Dúbravská cesta 21 , 845 51 Bratislava , Slovak Republic
| | - Gabriela Flores-Ramírez
- Biomedical Research Center, Institute of Virology , Slovak Academy of Sciences , Dubravska cesta 9 , 845 05 Bratislava , Slovak Republic
| | - Miroslav Glasa
- Biomedical Research Center, Institute of Virology , Slovak Academy of Sciences , Dubravska cesta 9 , 845 05 Bratislava , Slovak Republic
| |
Collapse
|
10
|
Vitlin Gruber A, Vugman M, Azem A, Weiss CE. Reconstitution of Pure Chaperonin Hetero-Oligomer Preparations in Vitro by Temperature Modulation. Front Mol Biosci 2018; 5:5. [PMID: 29435453 PMCID: PMC5790771 DOI: 10.3389/fmolb.2018.00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/11/2018] [Indexed: 01/13/2023] Open
Abstract
Chaperonins are large, essential, oligomers that facilitate protein folding in chloroplasts, mitochondria, and eubacteria. Plant chloroplast chaperonins are comprised of multiple homologous subunits that exhibit unique properties. We previously characterized homogeneous, reconstituted, chloroplast-chaperonin oligomers in vitro, each composed of one of three highly homologous beta subunits from A. thaliana. In the current work, we describe alpha-type subunits from the same species and investigate their interaction with β subtypes. Neither alpha subunit was capable of forming higher-order oligomers on its own. When combined with β subunits in the presence of Mg-ATP, only the α2 subunit was able to form stable functional hetero-oligomers, which were capable of refolding denatured protein with native chloroplast co-chaperonins. Since β oligomers were able to oligomerize in the absence of α, we sought conditions under which αβ hetero-oligomers could be produced without contamination of β homo-oligomers. We found that β2 subunits are unable to oligomerize at low temperatures and used this property to obtain homogenous preparations of functional α2β2 hetero-oligomers. The results of this study highlight the importance of reaction conditions such as temperature and concentration for the reconstitution of chloroplast chaperonin oligomers in vitro.
Collapse
Affiliation(s)
- Anna Vitlin Gruber
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Milena Vugman
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Celeste E Weiss
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
11
|
Zhao Q, Liu C. Chloroplast Chaperonin: An Intricate Protein Folding Machine for Photosynthesis. Front Mol Biosci 2018; 4:98. [PMID: 29404339 PMCID: PMC5780408 DOI: 10.3389/fmolb.2017.00098] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 12/28/2017] [Indexed: 11/13/2022] Open
Abstract
Group I chaperonins are large cylindrical-shaped nano-machines that function as a central hub in the protein quality control system in the bacterial cytosol, mitochondria and chloroplasts. In chloroplasts, proteins newly synthesized by chloroplast ribosomes, unfolded by diverse stresses, or translocated from the cytosol run the risk of aberrant folding and aggregation. The chloroplast chaperonin system assists these proteins in folding into their native states. A widely known protein folded by chloroplast chaperonin is the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), an enzyme responsible for the fixation of inorganic CO2 into organic carbohydrates during photosynthesis. Chloroplast chaperonin was initially identified as a Rubisco-binding protein. All photosynthetic eucaryotes genomes encode multiple chaperonin genes which can be divided into α and β subtypes. Unlike the homo-oligomeric chaperonins from bacteria and mitochondria, chloroplast chaperonins are more complex and exists as intricate hetero-oligomers containing both subtypes. The Group I chaperonin requires proper interaction with a detachable lid-like co-chaperonin in the presence of ATP and Mg2+ for substrate encapsulation and conformational transition. Besides the typical Cpn10-like co-chaperonin, a unique co-chaperonin consisting of two tandem Cpn10-like domains joined head-to-tail exists in chloroplasts. Since chloroplasts were proposed as sensors to various environmental stresses, this diversified chloroplast chaperonin system has the potential to adapt to complex conditions by accommodating specific substrates or through regulation at both the transcriptional and post-translational levels. In this review, we discuss recent progress on the unique structure and function of the chloroplast chaperonin system based on model organisms Chlamydomonas reinhardtii and Arabidopsis thaliana. Knowledge of the chloroplast chaperonin system may ultimately lead to successful reconstitution of eukaryotic Rubisco in vitro.
Collapse
Affiliation(s)
- Qian Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
12
|
Ke X, Zou W, Ren Y, Wang Z, Li J, Wu X, Zhao J. Functional divergence of chloroplast Cpn60α subunits during Arabidopsis embryo development. PLoS Genet 2017; 13:e1007036. [PMID: 28961247 PMCID: PMC5636168 DOI: 10.1371/journal.pgen.1007036] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/11/2017] [Accepted: 09/20/2017] [Indexed: 02/03/2023] Open
Abstract
Chaperonins are a class of molecular chaperones that assist in the folding and assembly of a wide range of substrates. In plants, chloroplast chaperonins are composed of two different types of subunits, Cpn60α and Cpn60β, and duplication of Cpn60α and Cpn60β genes occurs in a high proportion of plants. However, the importance of multiple Cpn60α and Cpn60β genes in plants is poorly understood. In this study, we found that loss-of-function of CPNA2 (AtCpn60α2), a gene encoding the minor Cpn60α subunit in Arabidopsis thaliana, resulted in arrested embryo development at the globular stage, whereas the other AtCpn60α gene encoding the dominant Cpn60α subunit, CPNA1 (AtCpn60α1), mainly affected embryonic cotyledon development at the torpedo stage and thereafter. Further studies demonstrated that CPNA2 can form a functional chaperonin with CPNB2 (AtCpn60β2) and CPNB3 (AtCpn60β3), while the functional partners of CPNA1 are CPNB1 (AtCpn60β1) and CPNB2. We also revealed that the functional chaperonin containing CPNA2 could assist the folding of a specific substrate, KASI (β-ketoacyl-[acyl carrier protein] synthase I), and that the KASI protein level was remarkably reduced due to loss-of-function of CPNA2. Furthermore, the reduction in the KASI protein level was shown to be the possible cause for the arrest of cpna2 embryos. Our findings indicate that the two Cpn60α subunits in Arabidopsis play different roles during embryo development through forming distinct chaperonins with specific AtCpn60β to assist the folding of particular substrates, thus providing novel insights into functional divergence of Cpn60α subunits in plants. Chaperonins are large oligomeric complexes that are involved in the folding and assembly of numerous proteins in various species. In contrast to other types of chaperonins, chloroplast chaperonins are characterized by the hetero-oligomeric structure composed of two unique types of subunits, Cpn60α and Cpn60β, each of which is present in two or more paralogous forms in most of higher plants. However, the functional significance underlying the wide array of subunit types and complex oligomeric arrangement remains largely unknown. Here, we investigated the role of the minor Cpn60α subunit AtCpn60α2 in Arabidopsis embryo development, and found that AtCpn60α2 is important for the transition of globular embryos to heart-shaped embryos, whereas loss of the dominant Cpn60α subunit AtCpn60α1 affects embryonic cotyledon development. Further studies demonstrated that AtCpn60α2 could form functional chaperonins with AtCpn60β2 and AtCpn60β3 to specifically assist in folding of the substrate KASI, which is important for the formation of heart-shaped embryos. Our results suggest that duplication of Cpn60α genes in higher plants can increase the potential number of chloroplast chaperonin substrates and provide chloroplast chaperonins with more roles in plant growth and development, thus revealing the relationship between duplication and functional specialization of chaperonin genes.
Collapse
Affiliation(s)
- Xiaolong Ke
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wenxuan Zou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yafang Ren
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Zhiqin Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jin Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xuan Wu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
- * E-mail:
| |
Collapse
|
13
|
Zhang S, Zhou H, Yu F, Gao F, He J, Liu C. Functional Partition of Cpn60α and Cpn60β Subunits in Substrate Recognition and Cooperation with Co-chaperonins. MOLECULAR PLANT 2016; 9:1210-1213. [PMID: 27179919 DOI: 10.1016/j.molp.2016.04.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/29/2016] [Accepted: 04/26/2016] [Indexed: 06/05/2023]
Affiliation(s)
- Shijia Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100101, China
| | - Huan Zhou
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
| | - Feng Yu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
| | - Feng Gao
- Center for Molecular Systems Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianhua He
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
14
|
Guo P, Jiang S, Bai C, Zhang W, Zhao Q, Liu C. Asymmetric functional interaction between chaperonin and its plastidic cofactors. FEBS J 2015; 282:3959-70. [DOI: 10.1111/febs.13390] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 07/07/2015] [Accepted: 07/30/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Peng Guo
- State Key Laboratory of Plant Cell and Chromosome Engineering; Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
- University of Chinese Academy of Sciences; Beijing China
| | - Shan Jiang
- State Key Laboratory of Plant Cell and Chromosome Engineering; Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
- University of Chinese Academy of Sciences; Beijing China
| | - Cuicui Bai
- State Key Laboratory of Plant Cell and Chromosome Engineering; Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
- University of Chinese Academy of Sciences; Beijing China
| | - Wenjuan Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering; Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
| | - Qian Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering; Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
- University of Chinese Academy of Sciences; Beijing China
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering; Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
| |
Collapse
|
15
|
Hauser T, Popilka L, Hartl FU, Hayer-Hartl M. Role of auxiliary proteins in Rubisco biogenesis and function. NATURE PLANTS 2015; 1:15065. [PMID: 27250005 DOI: 10.1038/nplants.2015.65] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 04/20/2015] [Indexed: 05/05/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyses the conversion of atmospheric CO2 into organic compounds during photosynthesis. Despite its pivotal role in plant metabolism, Rubisco is an inefficient enzyme and has therefore been a key target in bioengineering efforts to improve crop yields. Much has been learnt about the complex cellular machinery involved in Rubisco assembly and metabolic repair over recent years. The simple form of Rubisco found in certain bacteria and dinoflagellates comprises two large subunits, and generally requires the chaperonin system for folding. However, the evolution of hexadecameric Rubisco, which comprises eight large and eight small subunits, from its dimeric precursor has rendered Rubisco in most plants, algae, cyanobacteria and proteobacteria dependent on an array of additional factors. These auxiliary factors include several chaperones for assembly as well as ATPases of the AAA+ family for functional maintenance. An integrated view of the pathways underlying Rubisco biogenesis and repair will pave the way for efforts to improve the enzyme with the goal of increasing crop yields.
Collapse
Affiliation(s)
- Thomas Hauser
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Leonhard Popilka
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| |
Collapse
|
16
|
Trösch R, Mühlhaus T, Schroda M, Willmund F. ATP-dependent molecular chaperones in plastids--More complex than expected. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:872-88. [PMID: 25596449 DOI: 10.1016/j.bbabio.2015.01.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/03/2015] [Accepted: 01/08/2015] [Indexed: 11/27/2022]
Abstract
Plastids are a class of essential plant cell organelles comprising photosynthetic chloroplasts of green tissues, starch-storing amyloplasts of roots and tubers or the colorful pigment-storing chromoplasts of petals and fruits. They express a few genes encoded on their organellar genome, called plastome, but import most of their proteins from the cytosol. The import into plastids, the folding of freshly-translated or imported proteins, the degradation or renaturation of denatured and entangled proteins, and the quality-control of newly folded proteins all require the action of molecular chaperones. Members of all four major families of ATP-dependent molecular chaperones (chaperonin/Cpn60, Hsp70, Hsp90 and Hsp100 families) have been identified in plastids from unicellular algae to higher plants. This review aims not only at giving an overview of the most current insights into the general and conserved functions of these plastid chaperones, but also into their specific plastid functions. Given that chloroplasts harbor an extreme environment that cycles between reduced and oxidized states, that has to deal with reactive oxygen species and is highly reactive to environmental and developmental signals, it can be presumed that plastid chaperones have evolved a plethora of specific functions some of which are just about to be discovered. Here, the most urgent questions that remain unsolved are discussed, and guidance for future research on plastid chaperones is given. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
Collapse
Affiliation(s)
- Raphael Trösch
- TU Kaiserslautern, Molecular Biotechnology & Systems Biology, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany; HU Berlin, Institute of Biology, Chausseestraße 117, 10115 Berlin, Germany; TU Kaiserslautern, Molecular Genetics of Eukaryotes, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany.
| | - Timo Mühlhaus
- TU Kaiserslautern, Molecular Biotechnology & Systems Biology, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany.
| | - Michael Schroda
- TU Kaiserslautern, Molecular Biotechnology & Systems Biology, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany.
| | - Felix Willmund
- TU Kaiserslautern, Molecular Genetics of Eukaryotes, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany.
| |
Collapse
|
17
|
Vitlin Gruber A, Zizelski G, Azem A, Weiss C. The Cpn10(1) co-chaperonin of A. thaliana functions only as a hetero-oligomer with Cpn20. PLoS One 2014; 9:e113835. [PMID: 25419702 PMCID: PMC4242682 DOI: 10.1371/journal.pone.0113835] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 10/31/2014] [Indexed: 12/16/2022] Open
Abstract
The A. thaliana genome encodes five co-chaperonin homologs, three of which are destined to the chloroplast. Two of the proteins, Cpn10(2) and Cpn20, form functional homo-oligomers in vitro. In the current work, we present data on the structure and function of the third A. thaliana co-chaperonin, which exhibits unique properties. We found that purified recombinant Cpn10(1) forms inactive dimers in solution, in contrast to the active heptamers that are formed by canonical Cpn10s. Additionally, our data demonstrate that Cpn10(1) is capable of assembling into active hetero-oligomers together with Cpn20. This finding was reinforced by the formation of active co-chaperonin species upon mixing an inactive Cpn20 mutant with the inactive Cpn10(1). The present study constitutes the first report of a higher plant Cpn10 subunit that is able to function only upon formation of hetero-oligomers with other co-chaperonins.
Collapse
Affiliation(s)
- Anna Vitlin Gruber
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Gal Zizelski
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
| | - Celeste Weiss
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
18
|
Joshi J, Mueller-Cajar O, Tsai YCC, Hartl FU, Hayer-Hartl M. Role of small subunit in mediating assembly of red-type form I Rubisco. J Biol Chem 2014; 290:1066-74. [PMID: 25371207 DOI: 10.1074/jbc.m114.613091] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is the key enzyme involved in photosynthetic carbon fixation, converting atmospheric CO2 to organic compounds. Form I Rubisco is a cylindrical complex composed of eight large (RbcL) subunits that are capped by four small subunits (RbcS) at the top and four at the bottom. Form I Rubiscos are phylogenetically divided into green- and red-type. Some red-type enzymes have catalytically superior properties. Thus, understanding their folding and assembly is of considerable biotechnological interest. Folding of the green-type RbcL subunits in cyanobacteria is mediated by the GroEL/ES chaperonin system, and assembly to holoenzyme requires specialized chaperones such as RbcX and RAF1. Here, we show that the red-type RbcL subunits in the proteobacterium Rhodobacter sphaeroides also fold with GroEL/ES. However, assembly proceeds in a chaperone-independent manner. We find that the C-terminal β-hairpin extension of red-type RbcS, which is absent in green-type RbcS, is critical for efficient assembly. The β-hairpins of four RbcS subunits form an eight-stranded β-barrel that protrudes into the central solvent channel of the RbcL core complex. The two β-barrels stabilize the complex through multiple interactions with the RbcL subunits. A chimeric green-type RbcS carrying the C-terminal β-hairpin renders the assembly of a cyanobacterial Rubisco independent of RbcX. Our results may facilitate the engineering of crop plants with improved growth properties expressing red-type Rubisco.
Collapse
Affiliation(s)
- Jidnyasa Joshi
- From the Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Oliver Mueller-Cajar
- From the Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Yi-Chin C Tsai
- From the Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- From the Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Manajit Hayer-Hartl
- From the Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| |
Collapse
|
19
|
Arabidopsis co-chaperonin CPN20 antagonizes Mg-chelatase H subunit to derepress ABA-responsive WRKY40 transcription repressor. SCIENCE CHINA-LIFE SCIENCES 2013; 57:11-21. [DOI: 10.1007/s11427-013-4587-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 11/20/2013] [Indexed: 10/25/2022]
|
20
|
Vitlin Gruber A, Nisemblat S, Azem A, Weiss C. The complexity of chloroplast chaperonins. TRENDS IN PLANT SCIENCE 2013; 18:688-94. [PMID: 24035661 DOI: 10.1016/j.tplants.2013.08.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 07/29/2013] [Accepted: 08/07/2013] [Indexed: 05/07/2023]
Abstract
Type I chaperonins are large oligomeric protein ensembles that are involved in the folding and assembly of other proteins. Chloroplast chaperonins and co-chaperonins exist in multiple copies of two distinct isoforms that can combine to form a range of labile oligomeric structures. This complex system increases the potential number of chaperonin substrates and possibilities for regulation. The incorporation of unique subunits into the oligomer can modify substrate specificity. Some subunits are upregulated in response to heat shock and some show organ-specific expression, whereas others possess additional functions that are unrelated to their role in protein folding. Accumulating evidence suggests that specific subunits have distinct roles in biogenesis of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco).
Collapse
Affiliation(s)
- Anna Vitlin Gruber
- The George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Ramat Aviv, Israel
| | | | | | | |
Collapse
|
21
|
Zhang XF, Jiang T, Wu Z, Du SY, Yu YT, Jiang SC, Lu K, Feng XJ, Wang XF, Zhang DP. Cochaperonin CPN20 negatively regulates abscisic acid signaling in Arabidopsis. PLANT MOLECULAR BIOLOGY 2013; 83:205-18. [PMID: 23783410 PMCID: PMC3777161 DOI: 10.1007/s11103-013-0082-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 05/26/2013] [Indexed: 05/08/2023]
Abstract
Previous study showed that the magnesium-protoporphyrin IX chelatase H subunit (CHLH/ABAR) positively regulates abscisic acid (ABA) signaling. Here, we investigated the functions of a CHLH/ABAR interaction protein, the chloroplast co-chaperonin 20 (CPN20) in ABA signaling in Arabidopsis thaliana. We showed that down-expression of the CPN20 gene increases, but overexpression of the CPN20 gene reduces, ABA sensitivity in the major ABA responses including ABA-induced seed germination inhibition, postgermination growth arrest, promotion of stomatal closure and inhibition of stomatal opening. Genetic evidence supports that CPN20 functions downstream or at the same node of CHLH/ABAR, but upstream of the WRKY40 transcription factor. The other CPN20 interaction partners CPN10 and CPN60 are not involved in ABA signaling. Our findings show that CPN20 functions negatively in the ABAR-WRKY40 coupled ABA signaling independently of its co-chaperonin role, and provide a new insight into the role of co-chaperones in the regulation of plant responses to environmental cues.
Collapse
Affiliation(s)
- Xiao-Feng Zhang
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Tao Jiang
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Zhen Wu
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Shu-Yuan Du
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Yong-Tao Yu
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Shang-Chuan Jiang
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Kai Lu
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Xiu-Jing Feng
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Xiao-Fang Wang
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Da-Peng Zhang
- MOE Systems Biology and Bioinformatics Laboratory, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| |
Collapse
|
22
|
Kim SR, Yang JI, An G. OsCpn60α1, encoding the plastid chaperonin 60α subunit, is essential for folding of rbcL. Mol Cells 2013; 35:402-9. [PMID: 23620301 PMCID: PMC3887859 DOI: 10.1007/s10059-013-2337-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 03/12/2013] [Accepted: 03/12/2013] [Indexed: 01/06/2023] Open
Abstract
Chaperonins are involved in protein-folding. The rice genome encodes six plastid chaperonin subunits (Cpn60) - three α and three β. Our study showed that they were differentially expressed during normal plant development. Moreover, five were induced by heat stress (42°C) but not by cold (10°C). The oscpn60α1 mutant had a pale-green phenotype at the seedling stage and development ceased after the fourth leaf appeared. Transiently expressed OsCpn60α1:GFP fusion protein was localized to the chloroplast stroma. Immuno-blot analysis indicated that the level of Rubisco large subunit (rbcL) was severely reduced in the mutant while levels were unchanged for some imported proteins, e.g., stromal heat shock protein 70 (Hsp70) and chlorophyll a/b binding protein 1 (Lhcb1). This demonstrated that OsCpn60α1 is required for the folding of rbcL and that failure of that process is seedling-lethal.
Collapse
Affiliation(s)
- Sung-Ryul Kim
- Crop Biotech Institute and Department of Genetic Engineering, Kyung Hee University, Yongin 446-701,
Korea
| | - Jung-Il Yang
- Crop Biotech Institute and Department of Genetic Engineering, Kyung Hee University, Yongin 446-701,
Korea
| | - Gynheung An
- Crop Biotech Institute and Department of Genetic Engineering, Kyung Hee University, Yongin 446-701,
Korea
| |
Collapse
|
23
|
Henderson B, Fares MA, Lund PA. Chaperonin 60: a paradoxical, evolutionarily conserved protein family with multiple moonlighting functions. Biol Rev Camb Philos Soc 2013; 88:955-87. [DOI: 10.1111/brv.12037] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 02/20/2013] [Accepted: 03/04/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Brian Henderson
- Department of Microbial Diseases, UCL-Eastman Dental Institute; University College London; London WC1X 8LD U.K
| | - Mario A. Fares
- Department of Genetics; University of Dublin, Trinity College Dublin; Dublin 2 Ireland
- Department of Abiotic Stress; Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas (CSIC-UPV); Valencia 46022 Spain
| | - Peter A. Lund
- School of Biosciences; University of Birmingham; Birmingham B15 2TT U.K
| |
Collapse
|
24
|
Diversity in the origins of proteostasis networks--a driver for protein function in evolution. Nat Rev Mol Cell Biol 2013; 14:237-48. [PMID: 23463216 DOI: 10.1038/nrm3542] [Citation(s) in RCA: 182] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although the sequence of a protein largely determines its function, proteins can adopt different folding states in response to changes in the environment, some of which may be deleterious to the organism. All organisms--Bacteria, Archaea and Eukarya--have evolved a protein homeostasis, or proteostasis, network comprising chaperones and folding factors, degradation components, signalling pathways and specialized compartmentalized modules that manage protein folding in response to environmental stimuli and variation. Surveying the origins of proteostasis networks reveals that they have co-evolved with the proteome to regulate the physiological state of the cell, reflecting the unique stresses that different cells or organisms experience, and that they have a key role in driving evolution by closely managing the link between the phenotype and the genotype.
Collapse
|
25
|
Kuo WY, Huang CH, Jinn TL. Chaperonin 20 might be an iron chaperone for superoxide dismutase in activating iron superoxide dismutase (FeSOD). PLANT SIGNALING & BEHAVIOR 2013; 8:e23074. [PMID: 23299425 PMCID: PMC3657002 DOI: 10.4161/psb.23074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 11/30/2012] [Accepted: 11/30/2012] [Indexed: 05/20/2023]
Abstract
Activation of Cu/Zn superoxide dismutases (CuZnSODs) is aided by Cu incorporation and disulfide isomerization by Cu chaperone of SOD (CCS). As well, an Fe-S cluster scaffold protein, ISU, might alter the incorporation of Fe or Mn into yeast MnSOD (ySOD2), thus leading to active or inactive ySOD2. However, metallochaperones involved in the activation of FeSODs are unknown. Recently, we found that a chloroplastic chaperonin cofactor, CPN20, could mediate FeSOD activity. To investigate whether Fe incorporation in FeSOD is affected by CPN20, we used inductively coupled plasma mass spectrometry to analyze the ability of CPN20 to bind Fe. CPN20 could bind Fe, and the Fe binding to FeSOD was increased with CPN20 incubation. Thus, CPN20 might be an Fe chaperone for FeSOD activation, a role independent of its well-known co-chaperonin activity.
Collapse
|
26
|
Vitlin Gruber A, Nisemblat S, Zizelski G, Parnas A, Dzikowski R, Azem A, Weiss C. P. falciparum cpn20 is a bona fide co-chaperonin that can replace GroES in E. coli. PLoS One 2013; 8:e53909. [PMID: 23326533 PMCID: PMC3542282 DOI: 10.1371/journal.pone.0053909] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 12/04/2012] [Indexed: 02/05/2023] Open
Abstract
Human malaria is among the most ubiquitous and destructive tropical, parasitic diseases in the world today. The causative agent, Plasmodium falciparum, contains an unusual, essential organelle known as the apicoplast. Inhibition of this degenerate chloroplast results in second generation death of the parasite and is the mechanism by which antibiotics function in treating malaria. In order to better understand the biochemistry of this organelle, we have cloned a putative, 20 kDa, co-chaperonin protein, Pf-cpn20, which localizes to the apicoplast. Although this protein is homologous to the cpn20 that is found in plant chloroplasts, its ability to function as a co-chaperonin was questioned in the past. In the present study, we carried out a structural analysis of Pf-cpn20 using circular dichroism and analytical ultracentrifugation and then used two different approaches to investigate the ability of this protein to function as a co-chaperonin. In the first approach, we purified recombinant Pf-cpn20 and tested its ability to act as a co-chaperonin for GroEL in vitro, while in the second, we examined the ability of Pf-cpn20 to complement an E. coli depletion of the essential bacterial co-chaperonin GroES. Our results demonstrate that Pf-cpn20 is fully functional as a co-chaperonin in vitro. Moreover, the parasitic co-chaperonin is able to replace GroES in E. coli at both normal and heat-shock temperatures. Thus, Pf-cpn20 functions as a co-chaperonin in chaperonin-mediated protein folding. The ability of the malarial protein to function in E. coli suggests that this simple system can be used as a tool for further analyses of Pf-cpn20 and perhaps other chaperone proteins from P. falciparum.
Collapse
Affiliation(s)
- Anna Vitlin Gruber
- George E. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Ramat Aviv, Israel
| | | | | | | | | | | | | |
Collapse
|
27
|
Kuo WY, Huang CH, Liu AC, Cheng CP, Li SH, Chang WC, Weiss C, Azem A, Jinn TL. CHAPERONIN 20 mediates iron superoxide dismutase (FeSOD) activity independent of its co-chaperonin role in Arabidopsis chloroplasts. THE NEW PHYTOLOGIST 2013; 197:99-110. [PMID: 23057508 DOI: 10.1111/j.1469-8137.2012.04369.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 09/03/2012] [Indexed: 05/08/2023]
Abstract
Iron superoxide dismutases (FeSODs; FSDs) are primary antioxidant enzymes in Arabidopsis thaliana chloroplasts. The stromal FSD1 conferred the only detectable FeSOD activity, whereas the thylakoid membrane- and nucleoid-co-localized FSD2 and FSD3 double mutant showed arrested chloroplast development. FeSOD requires cofactor Fe for its activity, but its mechanism of activation is unclear. We used reversed-phase high-performance liquid chromatography (HPLC), gel filtration chromatography, LC-MS/MS, protoplast transient expression and virus-induced gene silencing (VIGS) analyses to identify and characterize a factor involved in FeSOD activation. We identified the chloroplast-localized co-chaperonin CHAPERONIN 20 (CPN20) as a mediator of FeSOD activation by direct interaction. The relationship between CPN20 and FeSOD was confirmed by in vitro experiments showing that CPN20 alone could enhance FSD1, FSD2 and FSD3 activity. The in vivo results showed that CPN20-overexpressing mutants and mutants with defective co-chaperonin activity increased FSD1 activity, without changing the chaperonin CPN60 protein level, and VIGS-induced downregulation of CPN20 also led to decreased FeSOD activity. Our findings reveal that CPN20 can mediate FeSOD activation in chloroplasts, a role independent of its known function in the chaperonin system.
Collapse
Affiliation(s)
- W Y Kuo
- Institute of Plant Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - C H Huang
- Institute of Plant Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - A C Liu
- Institute of Plant Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - C P Cheng
- Institute of Plant Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - S H Li
- Department of Medical Research, Mackay Memorial Hospital, Tamshui, 25160, Taiwan
| | - W C Chang
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - C Weiss
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - A Azem
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - T L Jinn
- Institute of Plant Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| |
Collapse
|
28
|
Tsai YCC, Mueller-Cajar O, Saschenbrecker S, Hartl FU, Hayer-Hartl M. Chaperonin cofactors, Cpn10 and Cpn20, of green algae and plants function as hetero-oligomeric ring complexes. J Biol Chem 2012; 287:20471-81. [PMID: 22518837 DOI: 10.1074/jbc.m112.365411] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The chloroplast chaperonin system of plants and green algae is a curiosity as both the chaperonin cage and its lid are encoded by multiple genes, in contrast to the single genes encoding the two components of the bacterial and mitochondrial systems. In the green alga Chlamydomonas reinhardtii (Cr), three genes encode chaperonin cofactors, with cpn10 encoding a single ∼10-kDa domain and cpn20 and cpn23 encoding tandem cpn10 domains. Here, we characterized the functional interaction of these proteins with the Escherichia coli chaperonin, GroEL, which normally cooperates with GroES, a heptamer of ∼10-kDa subunits. The C. reinhardtii cofactor proteins alone were all unable to assist GroEL-mediated refolding of bacterial ribulose-bisphosphate carboxylase/oxygenase but gained this ability when CrCpn20 and/or CrCpn23 was combined with CrCpn10. Native mass spectrometry indicated the formation of hetero-oligomeric species, consisting of seven ∼10-kDa domains. The cofactor "heptamers" interacted with GroEL and encapsulated substrate protein in a nucleotide-dependent manner. Different hetero-oligomer arrangements, generated by constructing cofactor concatamers, indicated a preferential heptamer configuration for the functional CrCpn10-CrCpn23 complex. Formation of heptamer Cpn10/Cpn20 hetero-oligomers was also observed with the Arabidopsis thaliana (At) cofactors, which functioned with the chloroplast chaperonin, AtCpn60α(7)β(7). It appears that hetero-oligomer formation occurs more generally for chloroplast chaperonin cofactors, perhaps adapting the chaperonin system for the folding of specific client proteins.
Collapse
Affiliation(s)
- Yi-Chin C Tsai
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | | | | | | | | |
Collapse
|
29
|
Flores-Pérez Ú, Jarvis P. Molecular chaperone involvement in chloroplast protein import. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:332-40. [PMID: 22521451 DOI: 10.1016/j.bbamcr.2012.03.019] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/16/2012] [Accepted: 03/31/2012] [Indexed: 11/19/2022]
Abstract
Chloroplasts are organelles of endosymbiotic origin that perform essential functions in plants. They contain about 3000 different proteins, the vast majority of which are nucleus-encoded, synthesized in precursor form in the cytosol, and transported into the chloroplasts post-translationally. These preproteins are generally imported via envelope complexes termed TOC and TIC (Translocon at the Outer/Inner envelope membrane of Chloroplasts). They must navigate different cellular and organellar compartments (e.g., the cytosol, the outer and inner envelope membranes, the intermembrane space, and the stroma) before arriving at their final destination. It is generally considered that preproteins are imported in a largely unfolded state, and the whole process is energy-dependent. Several chaperones and cochaperones have been found to mediate different stages of chloroplast import, in similar fashion to chaperone involvement in mitochondrial import. Cytosolic factors such as Hsp90, Hsp70 and 14-3-3 may assist preproteins to reach the TOC complex at the chloroplast surface, preventing their aggregation or degradation. Chaperone involvement in the intermembrane space has also been proposed, but remains uncertain. Preprotein translocation is completed at the trans side of the inner membrane by ATP-driven motor complexes. A stromal Hsp100-type chaperone, Hsp93, cooperates with Tic110 and Tic40 in one such motor complex, while stromal Hsp70 is proposed to act in a second, parallel complex. Upon arrival in the stroma, chaperones (e.g., Hsp70, Cpn60, cpSRP43) also contribute to the folding, assembly or onward intraorganellar guidance of the proteins. In this review, we focus on chaperone involvement during preprotein translocation at the chloroplast envelope. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
Collapse
|
30
|
Vitlin A, Weiss C, Demishtein-Zohary K, Rasouly A, Levin D, Pisanty-Farchi O, Breiman A, Azem A. Chloroplast β chaperonins from A. thaliana function with endogenous cpn10 homologs in vitro. PLANT MOLECULAR BIOLOGY 2011; 77:105-15. [PMID: 21633907 DOI: 10.1007/s11103-011-9797-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 05/18/2011] [Indexed: 05/15/2023]
Abstract
The involvement of type I chaperonins in bacterial and organellar protein folding has been well-documented. In E. coli and mitochondria, these ubiquitous and highly conserved proteins form chaperonin oligomers of identical 60 kDa subunits (cpn60), while in chloroplasts, two distinct cpn60 α and β subunit types co-exist together. The primary sequence of α and β subunits is ~50% identical, similar to their respective homologies to the bacterial GroEL. Moreover, the A. thaliana genome contains two α and four β genes. The functional significance of this variability in plant chaperonin proteins has not yet been elucidated. In order to gain insight into the functional variety of the chloroplast chaperonin family members, we reconstituted β homo-oligomers from A. thaliana following their expression in bacteria and subjected them to a structure-function analysis. Our results show for the first time, that A. thaliana β homo-oligomers can function in vitro with authentic chloroplast co-chaperonins (ch-cpn10 and ch-cpn20). We also show that oligomers made up of different β subunit types have unique properties and different preferences for co-chaperonin partners. We propose that chloroplasts may contain active β homo-oligomers in addition to hetero-oligomers, possibly reflecting a variety of cellular roles.
Collapse
Affiliation(s)
- Anna Vitlin
- Department of Biochemistry and Molecular Biology, Tel Aviv University, 69978 Tel Aviv, Israel
| | | | | | | | | | | | | | | |
Collapse
|
31
|
A chaperonin subunit with unique structures is essential for folding of a specific substrate. PLoS Biol 2011; 9:e1001040. [PMID: 21483722 PMCID: PMC3071376 DOI: 10.1371/journal.pbio.1001040] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 02/23/2011] [Indexed: 01/01/2023] Open
Abstract
Type I chaperonins are large, double-ring complexes present in bacteria (GroEL),
mitochondria (Hsp60), and chloroplasts (Cpn60), which are involved in mediating
the folding of newly synthesized, translocated, or stress-denatured proteins. In
Escherichia coli, GroEL comprises 14 identical subunits and
has been exquisitely optimized to fold its broad range of substrates. However,
multiple Cpn60 subunits with different expression profiles have evolved in
chloroplasts. Here, we show that, in Arabidopsis thaliana, the
minor subunit Cpn60β4 forms a heterooligomeric Cpn60 complex with
Cpn60α1 and Cpn60β1–β3 and is specifically required for the
folding of NdhH, a subunit of the chloroplast NADH dehydrogenase-like complex
(NDH). Other Cpn60β subunits cannot complement the function of Cpn60β4.
Furthermore, the unique C-terminus of Cpn60β4 is required for the full
activity of the unique Cpn60 complex containing Cpn60β4 for folding of NdhH.
Our findings suggest that this unusual kind of subunit enables the Cpn60 complex
to assist the folding of some particular substrates, whereas other dominant
Cpn60 subunits maintain a housekeeping chaperonin function by facilitating the
folding of other obligate substrates. Chaperonins assist the folding of some nascent and denatured proteins to their
native, functional forms. Each chaperonin consists of a pair of protein
complexes resembling two stacked toroids; folding occurs inside the toroid
cavity. Chaperonins are ubiquitous in both bacteria and more complex nucleated
cells, as well as in the intracellular organelles that have evolved from
bacteria by endosymbiosis: mitochondria and, in plants, chloroplasts. They are
indispensable for cellular function. Many different chaperonin subunits have
evolved in various species of bacteria as well as in most mitochondria and
chloroplasts. The physiological and functional relevance of these multiple
chaperonin subunits is poorly understood, however. In this study, we have
characterized the minor chaperonin subunit Cpn60β4 from
Arabidopsis chloroplasts, which differs in structure from
other chloroplast chaperonins. When the Cpn60β4 gene is
defective, the plants fail to accumulate one protein complex in particular: the
chloroplast NADH dehydrogenase-like complex (NDH). We discovered that
Cpn60β4 forms a complex with other Cpn60 α and β
subunits and that this complex is essential for the folding of the NDH subunit
NdhH. Cpn60β4 has a unique protein “tail” that is required for
the efficient folding of NdhH. Our findings suggest that Cpn60β4 has evolved
with distinctive structural features that facilitate the folding of one specific
substrate and that this strategy is used by plants to satisfy their conflicting
requirements for chaperonins with both specialized and general functions.
Collapse
|
32
|
Seeber F, Soldati-Favre D. Metabolic Pathways in the Apicoplast of Apicomplexa. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 281:161-228. [DOI: 10.1016/s1937-6448(10)81005-6] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
|