1
|
Eshenour K, Hotto A, Michel EJS, Oh ZG, Stern DB. Transgenic expression of Rubisco accumulation factor2 and Rubisco subunits increases photosynthesis and growth in maize. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4024-4037. [PMID: 38696303 DOI: 10.1093/jxb/erae186] [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: 11/01/2023] [Accepted: 05/01/2024] [Indexed: 05/04/2024]
Abstract
Carbon assimilation by Rubisco is often a limitation to photosynthesis and therefore plant productivity. We have previously shown that transgenic co-expression of the Rubisco large (LS) and small (SS) subunits along with an essential Rubisco accumulation factor, Raf1, leads to faster growth, increased photosynthesis, and enhanced chilling tolerance in maize (Zea mays). Maize also requires Rubisco accumulation factor2 (Raf2) for full accumulation of Rubisco. Here we have analyzed transgenic maize lines with increased expression of Raf2 or Raf2 plus LS and SS. We show that increasing Raf2 expression alone had minor effects on photosynthesis, whereas expressing Raf2 with Rubisco subunits led to increased Rubisco content, more rapid carbon assimilation, and greater plant height, most notably in plants at least 6 weeks of age. The magnitude of the effects was similar to what was observed previously for expression of Raf1 together with Rubisco subunits. Taken together, this suggests that increasing the amount of either assembly factor with Rubisco subunits can independently enhance Rubisco abundance and some aspects of plant performance. These results could also imply either synergy or a degree of functional redundancy for Raf1 and Raf2, the latter of whose precise role in Rubisco assembly is currently unknown.
Collapse
Affiliation(s)
| | - Amber Hotto
- Boyce Thompson Institute, 533 Tower Rd, Ithaca, NY 14853, USA
| | | | - Zhen Guo Oh
- Boyce Thompson Institute, 533 Tower Rd, Ithaca, NY 14853, USA
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - David B Stern
- Boyce Thompson Institute, 533 Tower Rd, Ithaca, NY 14853, USA
| |
Collapse
|
2
|
Gionfriddo M, Rhodes T, Whitney SM. Perspectives on improving crop Rubisco by directed evolution. Semin Cell Dev Biol 2024; 155:37-47. [PMID: 37085353 DOI: 10.1016/j.semcdb.2023.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 04/23/2023]
Abstract
Rubisco catalyses the entry of almost all CO2 into the biosphere and is often the rate-limiting step in plant photosynthesis and growth. Its notoriety as the most abundant protein on Earth stems from the slow and error-prone catalytic properties that require plants, cyanobacteria, algae and photosynthetic bacteria to produce it in high amounts. Efforts to improve the CO2-fixing properties of plant Rubisco has been spurred on by the discovery of more effective isoforms in some algae with the potential to significantly improve crop productivity. Incompatibilities between the protein folding machinery of leaf and algae chloroplasts have, so far, prevented efforts to transplant these more effective Rubisco variants into plants. There is therefore increasing interest in improving Rubisco catalysis by directed (laboratory) evolution. Here we review the advances being made in, and the ongoing challenges with, improving the solubility and/or carboxylation activity of differing non-plant Rubisco lineages. We provide perspectives on new opportunities for the directed evolution of crop Rubiscos and the existing plant transformation capabilities available to evaluate the extent to which Rubisco activity improvements can benefit agricultural productivity.
Collapse
Affiliation(s)
- Matteo Gionfriddo
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia; Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Timothy Rhodes
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Spencer M Whitney
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.
| |
Collapse
|
3
|
Wang R, Song H, Zhang W, Wang N, Zhang S, Shao R, Liu C. Structural insights into the functions of Raf1 and Bsd2 in hexadecameric Rubisco assembly. MOLECULAR PLANT 2023; 16:1927-1936. [PMID: 37853692 DOI: 10.1016/j.molp.2023.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 09/20/2023] [Accepted: 10/17/2023] [Indexed: 10/20/2023]
Abstract
Hexadecameric form I Rubisco, which consisting consists of eight large (RbcL) and eight small (RbcS) subunits, is the most abundant enzyme on earth. Extensive efforts to engineer an improved Rubisco to speed up its catalytic efficiency and ultimately increase agricultural productivity. However, difficulties with correct folding and assembly in foreign hosts or in vitro have hampered the genetic manipulation of hexadecameric Rubisco. In this study, we reconstituted Synechococcus sp. PCC6301 Rubisco in vitro using the chaperonin system and assembly factors from cyanobacteria and Arabidopsis thaliana (At). Rubisco holoenzyme was produced in the presence of cyanobacterial Rubisco accumulation factor 1 (Raf1) alone or both AtRaf1 and bundle-sheath defective-2 (AtBsd2) from Arabidopsis. RbcL released from GroEL is assembly capable in the presence of ATP, and AtBsd2 functions downstream of AtRaf1. Cryo-EM structures of RbcL8-AtRaf18, RbcL8-AtRaf14-AtBsd28, and RbcL8 revealed that the interactions between RbcL and AtRaf1 are looser than those between prokaryotic RbcL and Raf1, with AtRaf1 tilting 7° farther away from RbcL. AtBsd2 stabilizes the flexible regions of RbcL, including the N and C termini, the 60s loop, and loop 6. Using these data, combined with previous findings, we propose the possible biogenesis pathways of prokaryotic and eukaryotic Rubisco.
Collapse
Affiliation(s)
- Ran 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
| | - Hui Song
- 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
| | - 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 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
| | - Shijia 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 100101, China; University of Chinese Academy of Sciences, Beijing 100101, China
| | - Ruiqi Shao
- 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
| | - 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
|
4
|
Jin K, Chen G, Yang Y, Zhang Z, Lu T. Strategies for manipulating Rubisco and creating photorespiratory bypass to boost C 3 photosynthesis: Prospects on modern crop improvement. PLANT, CELL & ENVIRONMENT 2023; 46:363-378. [PMID: 36444099 DOI: 10.1111/pce.14500] [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: 09/15/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 06/16/2023]
Abstract
Photosynthesis is a process that uses solar energy to fix CO2 in the air and converts it into sugar, and ultimately powers almost all life activities on the earth. C3 photosynthesis is the most common form of photosynthesis in crops. Current efforts of increasing crop yields in response to growing global food requirement are mostly focused on improving C3 photosynthesis. In this review, we summarized the strategies of C3 photosynthesis improvement in terms of Rubisco properties and photorespiratory limitation. Potential engineered targets include Rubisco subunits and their catalytic sites, Rubisco assembly chaperones, and Rubisco activase. In addition, we reviewed multiple photorespiratory bypasses built by strategies of synthetic biology to reduce the release of CO2 and ammonia and minimize energy consumption by photorespiration. The potential strategies are suggested to enhance C3 photosynthesis and boost crop production.
Collapse
Affiliation(s)
- Kaining Jin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
- Department of Plant Sciences, Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Guoxin Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Yirong Yang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Zhiguo Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Tiegang Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| |
Collapse
|
5
|
Mao Y, Catherall E, Díaz-Ramos A, Greiff GRL, Azinas S, Gunn L, McCormick AJ. The small subunit of Rubisco and its potential as an engineering target. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:543-561. [PMID: 35849331 PMCID: PMC9833052 DOI: 10.1093/jxb/erac309] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/07/2022] [Indexed: 05/06/2023]
Abstract
Rubisco catalyses the first rate-limiting step in CO2 fixation and is responsible for the vast majority of organic carbon present in the biosphere. The function and regulation of Rubisco remain an important research topic and a longstanding engineering target to enhance the efficiency of photosynthesis for agriculture and green biotechnology. The most abundant form of Rubisco (Form I) consists of eight large and eight small subunits, and is found in all plants, algae, cyanobacteria, and most phototrophic and chemolithoautotrophic proteobacteria. Although the active sites of Rubisco are located on the large subunits, expression of the small subunit regulates the size of the Rubisco pool in plants and can influence the overall catalytic efficiency of the Rubisco complex. The small subunit is now receiving increasing attention as a potential engineering target to improve the performance of Rubisco. Here we review our current understanding of the role of the small subunit and our growing capacity to explore its potential to modulate Rubisco catalysis using engineering biology approaches.
Collapse
Affiliation(s)
| | | | - Aranzazú Díaz-Ramos
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, King’s Buildings, University of Edinburgh, Edingburgh EH9 3BF, UK
| | - George R L Greiff
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Stavros Azinas
- Department of Cell and Molecular Biology, Uppsala University, S-751 24 Uppsala, Sweden
| | - Laura Gunn
- Department of Cell and Molecular Biology, Uppsala University, S-751 24 Uppsala, Sweden
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | | |
Collapse
|
6
|
Buck S, Rhodes T, Gionfriddo M, Skinner T, Yuan D, Birch R, Kapralov MV, Whitney SM. Escherichia coli expressing chloroplast chaperones as a proxy to test heterologous Rubisco production in leaves. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:664-676. [PMID: 36322613 DOI: 10.1093/jxb/erac435] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Rubisco is a fundamental enzyme in photosynthesis and therefore for life. Efforts to improve plant Rubisco performance have been hindered by the enzymes' complex chloroplast biogenesis requirements. New Synbio approaches, however, now allow the production of some plant Rubisco isoforms in Escherichia coli. While this enhances opportunities for catalytic improvement, there remain limitations in the utility of the expression system. Here we generate, optimize, and test a robust Golden Gate cloning E. coli expression system incorporating the protein folding machinery of tobacco chloroplasts. By comparing the expression of different plant Rubiscos in both E. coli and plastome-transformed tobacco, we show that the E. coli expression system can accurately predict high level Rubisco production in chloroplasts but poorly forecasts the biogenesis potential of isoforms with impaired production in planta. We reveal that heterologous Rubisco production in E. coli and tobacco plastids poorly correlates with Rubisco large subunit phylogeny. Our findings highlight the need to fully understand the factors governing Rubisco biogenesis if we are to deliver an efficient, low-cost screening tool that can accurately emulate chloroplast expression.
Collapse
Affiliation(s)
- Sally Buck
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Tim Rhodes
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Matteo Gionfriddo
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Tanya Skinner
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Ding Yuan
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Rosemary Birch
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Maxim V Kapralov
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Spencer M Whitney
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| |
Collapse
|
7
|
Lin MT, Salihovic H, Clark FK, Hanson MR. Improving the efficiency of Rubisco by resurrecting its ancestors in the family Solanaceae. SCIENCE ADVANCES 2022; 8:eabm6871. [PMID: 35427154 PMCID: PMC9012466 DOI: 10.1126/sciadv.abm6871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plants and photosynthetic organisms have a remarkably inefficient enzyme named Rubisco that fixes atmospheric CO2 into organic compounds. Understanding how Rubisco has evolved in response to past climate change is important for attempts to adjust plants to future conditions. In this study, we developed a computational workflow to assemble de novo both large and small subunits of Rubisco enzymes from transcriptomics data. Next, we predicted sequences for ancestral Rubiscos of the (nightshade) family Solanaceae and characterized their kinetics after coexpressing them in Escherichia coli. Predicted ancestors of C3 Rubiscos were identified that have superior kinetics and excellent potential to help plants adapt to anthropogenic climate change. Our findings also advance understanding of the evolution of Rubisco's catalytic traits.
Collapse
|
8
|
Caruana L, Orr DJ, Carmo-Silva E. Rubiscosome gene expression is balanced across the hexaploid wheat genome. PHOTOSYNTHESIS RESEARCH 2022; 152:1-11. [PMID: 35083631 PMCID: PMC9090852 DOI: 10.1007/s11120-022-00897-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/06/2022] [Indexed: 05/22/2023]
Abstract
Functional and active Rubisco is essential for CO2 fixation and is a primary target for engineering approaches to increasing crop yields. However, the assembly and maintenance of active Rubisco are dependent on the coordinated biosynthesis of at least 11 nuclear-encoded proteins, termed the 'Rubiscosome'. Using publicly available gene expression data for wheat (Triticum aestivum L.), we show that the expression of Rubiscosome genes is balanced across the three closely related subgenomes that form the allohexaploid genome. Each subgenome contains a near complete set of homoeologous genes and contributes equally to overall expression, both under optimal and under heat stress conditions. The expression of the wheat thermo-tolerant Rubisco activase isoform 1β increases under heat stress and remains balanced across the subgenomes, albeit with a slight shift towards greater contribution from the D subgenome. The findings show that the gene copies in all three subgenomes need to be accounted for when designing strategies for crop improvement.
Collapse
Affiliation(s)
- Louis Caruana
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Douglas J Orr
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | | |
Collapse
|
9
|
Li ZQ, Zhang Y, Li H, Su TT, Liu CG, Han ZC, Wang AY, Zhu JB. Genome-Wide Characterization and Expression Analysis Provide Basis to the Biological Function of Cotton FBA Genes. FRONTIERS IN PLANT SCIENCE 2021; 12:696698. [PMID: 34490001 PMCID: PMC8416763 DOI: 10.3389/fpls.2021.696698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
Fructose-1,6-biphosphate aldolase (FBA) is a multifunctional enzyme in plants, which participates in the process of Calvin-Benson cycle, glycolysis and gluconeogenesis. Despite the importance of FBA genes in regulating plant growth, development and abiotic stress responses, little is known about their roles in cotton. In the present study, we performed a genome-wide identification and characterization of FBAs in Gossypium hirsutum. Totally seventeen GhFBA genes were identified. According to the analysis of functional domain, phylogenetic relationship, and gene structure, GhFBA genes were classified into two subgroups. Furthermore, nine GhFBAs were predicted to be in chloroplast and eight were located in cytoplasm. Moreover, the promoter prediction showed a variety of abiotic stresses and phytohormone related cis-acting elements exist in the 2k up-stream region of GhFBA. And the evolutionary characteristics of cotton FBA genes were clearly presented by synteny analysis. Moreover, the results of transcriptome and qRT-PCR analysis showed that the expression of GhFBAs were related to the tissue distribution, and further analysis suggested that GhFBAs could respond to various abiotic stress and phytohormonal treatments. Overall, our systematic analysis of GhFBA genes would not only provide a basis for the understanding of the evolution of GhFBAs, but also found a foundation for the further function analysis of GhFBAs to improve cotton yield and environmental adaptability.
Collapse
|
10
|
Wietrzynski W, Traverso E, Wollman FA, Wostrikoff K. The state of oligomerization of Rubisco controls the rate of synthesis of the Rubisco large subunit in Chlamydomonas reinhardtii. THE PLANT CELL 2021; 33:1706-1727. [PMID: 33625514 PMCID: PMC8254502 DOI: 10.1093/plcell/koab061] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/12/2021] [Indexed: 05/22/2023]
Abstract
Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) is present in all photosynthetic organisms and is a key enzyme for photosynthesis-driven life on Earth. Its most prominent form is a hetero-oligomer in which small subunits (SSU) stabilize the core of the enzyme built from large subunits (LSU), yielding, after a chaperone-assisted multistep assembly process, an LSU8SSU8 hexadecameric holoenzyme. Here we use Chlamydomonas reinhardtii and a combination of site-directed mutants to dissect the multistep biogenesis pathway of Rubisco in vivo. We identify assembly intermediates, in two of which LSU are associated with the RAF1 chaperone. Using genetic and biochemical approaches we further unravel a major regulation process during Rubisco biogenesis, in which LSU translation is controlled by its ability to assemble with the SSU, via the mechanism of control by epistasy of synthesis (CES). Altogether this leads us to propose a model whereby the last assembly intermediate, an LSU8-RAF1 complex, provides the platform for SSU binding to form the Rubisco enzyme, and when SSU is not available, converts to a key regulatory form that exerts negative feedback on the initiation of LSU translation.
Collapse
Affiliation(s)
- Wojciech Wietrzynski
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Eleonora Traverso
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
| | - Francis-André Wollman
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
| | - Katia Wostrikoff
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
| |
Collapse
|
11
|
Hotto AM, Salesse-Smith C, Lin M, Busch FA, Simpson I, Stern DB. Rubisco production in maize mesophyll cells through ectopic expression of subunits and chaperones. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4930-4937. [PMID: 33928359 DOI: 10.1093/jxb/erab189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
C4 plants, such as maize, strictly compartmentalize Rubisco to bundle sheath chloroplasts. The molecular basis for the restriction of Rubisco from the more abundant mesophyll chloroplasts is not fully understood. Mesophyll chloroplasts transcribe the Rubisco large subunit gene and, when normally quiescent transcription of the nuclear Rubisco small subunit gene family is overcome by ectopic expression, mesophyll chloroplasts still do not accumulate measurable Rubisco. Here we show that a combination of five ubiquitin promoter-driven nuclear transgenes expressed in maize leads to mesophyll accumulation of assembled Rubisco. These encode the Rubisco large and small subunits, Rubisco assembly factors 1 and 2, and the assembly factor Bundle sheath defective 2. In these plants, Rubisco large subunit accumulates in mesophyll cells, and appears to be assembled into a holoenzyme capable of binding the substrate analog CABP (carboxyarabinitol bisphosphate). Isotope discrimination assays suggest, however, that mesophyll Rubisco is not participating in carbon assimilation in these plants, most probably due to a lack of the substrate ribulose 1,5-bisphosphate and/or Rubisco activase. Overall, this work defines a minimal set of Rubisco assembly factors in planta and may help lead to methods of regulating the C4 pathway.
Collapse
Affiliation(s)
| | | | - Myat Lin
- Cornell University, Ithaca, NY, USA
| | - Florian A Busch
- School of Biosciences, and Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, UK
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | | | | |
Collapse
|
12
|
Feiz L, Strickler SR, van Eck J, Mao L, Movahed N, Taylor C, Gourabathini P, Fei Z, Stern DB. Setaria viridis chlorotic and seedling-lethal mutants define critical functions for chloroplast gene expression. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:917-931. [PMID: 32812296 DOI: 10.1111/tpj.14968] [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: 10/01/2018] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Deep insights into chloroplast biogenesis have been obtained by mutant analysis; however, in C4 plants a relevant mutant collection has only been developed and exploited for maize. Here, we report the initial characterization of an ethyl methyl sulfonate-induced mutant population for the C4 model Setaria viridis. Approximately 1000 M2 families were screened for the segregation of pale-green seedlings in the M3 generation, and a subset of these was identified to be deficient in post-transcriptional steps of chloroplast gene expression. Causative mutations were identified for three lines using deep sequencing-based bulked segregant analysis, and in one case confirmed by transgenic complementation. Using chloroplast RNA-sequencing and other molecular assays, we describe phenotypes of mutants deficient in PSRP7, a plastid-specific ribosomal protein, OTP86, an RNA editing factor, and cpPNP, the chloroplast isozyme of polynucleotide phosphorylase. The psrp mutant is globally defective in chloroplast translation, and has varying deficiencies in the accumulation of chloroplast-encoded proteins. The otp86 mutant, like its Arabidopsis counterpart, is specifically defective in editing of the rps14 mRNA; however, the conditional pale-green mutant phenotype contrasts with the normal growth of the Arabidopsis mutant. The pnp mutant exhibited multiple defects in 3' end maturation as well as other qualitative changes in the chloroplast RNA population. Overall, our collection opens the door to global analysis of photosynthesis and early seedling development in an emerging C4 model.
Collapse
Affiliation(s)
- Leila Feiz
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
| | | | - Joyce van Eck
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
| | - Linyong Mao
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
- Department of Biochemistry and Molecular Biology, Howard University, Washington, DC, 20059, USA
| | - Navid Movahed
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
- Q² Solutions, Ithaca, New York, 14850, USA
| | - Caroline Taylor
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
- Lansing High School, Lansing, New York, 14882, USA
- Cornell University, Ithaca, New York, New York, 14850, USA
| | | | - Zhangjun Fei
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
| | - David B Stern
- Boyce Thompson Institute, Ithaca, New York, 14853, USA
| |
Collapse
|
13
|
Flamholz AI, Dugan E, Blikstad C, Gleizer S, Ben-Nissan R, Amram S, Antonovsky N, Ravishankar S, Noor E, Bar-Even A, Milo R, Savage DF. Functional reconstitution of a bacterial CO 2 concentrating mechanism in Escherichia coli. eLife 2020; 9:59882. [PMID: 33084575 PMCID: PMC7714395 DOI: 10.7554/elife.59882] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/20/2020] [Indexed: 12/19/2022] Open
Abstract
Many photosynthetic organisms employ a CO2 concentrating mechanism (CCM) to increase the rate of CO2 fixation via the Calvin cycle. CCMs catalyze ≈50% of global photosynthesis, yet it remains unclear which genes and proteins are required to produce this complex adaptation. We describe the construction of a functional CCM in a non-native host, achieved by expressing genes from an autotrophic bacterium in an Escherichia coli strain engineered to depend on rubisco carboxylation for growth. Expression of 20 CCM genes enabled E. coli to grow by fixing CO2 from ambient air into biomass, with growth in ambient air depending on the components of the CCM. Bacterial CCMs are therefore genetically compact and readily transplanted, rationalizing their presence in diverse bacteria. Reconstitution enabled genetic experiments refining our understanding of the CCM, thereby laying the groundwork for deeper study and engineering of the cell biology supporting CO2 assimilation in diverse organisms.
Collapse
Affiliation(s)
- Avi I Flamholz
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Eli Dugan
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Shmuel Gleizer
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Roee Ben-Nissan
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Shira Amram
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Niv Antonovsky
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Sumedha Ravishankar
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Elad Noor
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Arren Bar-Even
- Max Planck Institute of Molecular Plant PhysiologyPotsdamGermany
| | - Ron Milo
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| |
Collapse
|
14
|
Lin MT, Stone WD, Chaudhari V, Hanson MR. Small subunits can determine enzyme kinetics of tobacco Rubisco expressed in Escherichia coli. NATURE PLANTS 2020; 6:1289-1299. [PMID: 32929197 DOI: 10.1038/s41477-020-00761-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/28/2020] [Indexed: 05/19/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) catalyses the first step in carbon fixation and is a strategic target for improving photosynthetic efficiency. In plants, Rubisco is composed of eight large and eight small subunits, and its biogenesis requires multiple chaperones. Here, we optimized a system to produce tobacco Rubisco in Escherichia coli by coexpressing chaperones in autoinduction medium. We successfully assembled tobacco Rubisco in E. coli with each small subunit that is normally encoded by the nuclear genome. Even though each enzyme carries only a single type of small subunit in E. coli, the enzymes exhibit carboxylation kinetics that are very similar to the carboxylation kinetics of the native Rubisco. Tobacco Rubisco assembled with a recently discovered trichome small subunit has a higher catalytic rate and a lower CO2 affinity compared with Rubisco complexes that are assembled with other small subunits. Our E. coli expression system will enable the analysis of features of both subunits of Rubisco that affect its kinetic properties.
Collapse
Affiliation(s)
- Myat T Lin
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - William D Stone
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, USA
| | | | - Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
| |
Collapse
|
15
|
Chaperone Machineries of Rubisco – The Most Abundant Enzyme. Trends Biochem Sci 2020; 45:748-763. [DOI: 10.1016/j.tibs.2020.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/19/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022]
|
16
|
Li H, Bai M, Jiang X, Shen R, Wang H, Wang H, Wu H. Cytological evidence of BSD2 functioning in both chloroplast division and dimorphic chloroplast formation in maize leaves. BMC PLANT BIOLOGY 2020; 20:17. [PMID: 31918680 PMCID: PMC6953307 DOI: 10.1186/s12870-019-2219-7] [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: 09/25/2019] [Accepted: 12/26/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Maize bsd2 (bundle sheath defective2) is a classical C4 mutant with defective C4 photosynthesis, accompanied with reduced accumulation of Rubisco (ribulose bisphosphate carboxylase oxygenase) and aberrant mature chloroplast morphology in the bundle sheath (BS) cells. However, as a hypothetical chloroplast chaperone, the effects of BSD2 on C4 chloroplast development have not been fully examined yet, which precludes a full appreciation of BSD2 function in C4 photosynthesis. The aims of our study are to find out the role ofBSD2 in regulating chloroplasts development in maize leaves, and to add new insights into our understanding of C4 biology. RESULTS We found that at the chloroplast maturation stage, the thylakoid membranes of chloroplasts in the BS and mesophyll (M) cells became significantly looser, and the granaof chloroplasts in the M cells became thinner stacking in the bsd2 mutant when compared with the wildtype plant. Moreover, at the early chloroplast development stage, the number of dividing chloroplasts and the chloroplast division rate are both reduced in the bsd2 mutant, compared with wild type. Quantitative reverse transcriptase-PCR analysis revealed that the expression of both thylakoid formation-related genesand chloroplast division-related genes is significantly reduced in the bsd2 mutants. Further, we showed that BSD2 interacts physically with the large submit of Rubisco (LS) in Bimolecular Fluorescence Complementation assay. CONCLUSIONS Our combined results suggest that BSD2 plays an essential role in regulating the division and differentiation of the dimorphic BS and M chloroplasts, and that it acts at a post-transcriptional level to regulate LS stability or assembly of Rubisco.
Collapse
Affiliation(s)
- Heying Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Mei Bai
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Xingshan Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Rongxin Shen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Huina Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Haiyang Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Hong Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642 China
| |
Collapse
|
17
|
Abstract
Over 100 whole-genome sequences from algae are published or soon to be published. The rapidly increasing availability of these fundamental resources is changing how we understand one of the most diverse, complex, and understudied groups of photosynthetic eukaryotes. Genome sequences provide a window into the functional potential of individual algae, with phylogenomics and functional genomics as tools for contextualizing and transferring knowledge from reference organisms into less well-characterized systems. Remarkably, over half of the proteins encoded by algal genomes are of unknown function, highlighting the volume of functional capabilities yet to be discovered. In this review, we provide an overview of publicly available algal genomes, their associated protein inventories, and their quality, with a summary of the statuses of protein function understanding and predictions.
Collapse
Affiliation(s)
| | - Sabeeha S Merchant
- Departments of Plant and Microbial Biology and Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
- Institute for Genomics and Proteomics, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
18
|
Conlan B, Birch R, Kelso C, Holland S, De Souza AP, Long SP, Beck JL, Whitney SM. BSD2 is a Rubisco-specific assembly chaperone, forms intermediary hetero-oligomeric complexes, and is nonlimiting to growth in tobacco. PLANT, CELL & ENVIRONMENT 2019; 42:1287-1301. [PMID: 30375663 DOI: 10.1111/pce.13473] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/30/2018] [Accepted: 10/22/2018] [Indexed: 05/28/2023]
Abstract
The folding and assembly of Rubisco large and small subunits into L8 S8 holoenzyme in chloroplasts involves many auxiliary factors, including the chaperone BSD2. Here we identify apparent intermediary Rubisco-BSD2 assembly complexes in the model C3 plant tobacco. We show BSD2 and Rubisco content decrease in tandem with leaf age with approximately half of the BSD2 in young leaves (~70 nmol BSD2 protomer.m2 ) stably integrated in putative intermediary Rubisco complexes that account for <0.2% of the L8 S8 pool. RNAi-silencing BSD2 production in transplastomic tobacco producing bacterial L2 Rubisco had no effect on leaf photosynthesis, cell ultrastructure, or plant growth. Genetic crossing the same RNAi-bsd2 alleles into wild-type tobacco however impaired L8 S8 Rubisco production and plant growth, indicating the only critical function of BSD2 is in Rubisco biogenesis. Agrobacterium mediated transient expression of tobacco, Arabidopsis, or maize BSD2 reinstated Rubisco biogenesis in BSD2-silenced tobacco. Overexpressing BSD2 in tobacco chloroplasts however did not alter Rubisco content, activation status, leaf photosynthesis rate, or plant growth in the field or in the glasshouse at 20°C or 35°C. Our findings indicate BSD2 functions exclusively in Rubisco biogenesis, can efficiently facilitate heterologous plant Rubisco assembly, and is produced in amounts nonlimiting to tobacco growth.
Collapse
Affiliation(s)
- Brendon Conlan
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Rosemary Birch
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Celine Kelso
- School of Chemistry, Molecular Horizons, University of Wollongong, New South Wales, Australia
| | - Sophie Holland
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Amanda P De Souza
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
| | - Stephen P Long
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Jennifer L Beck
- School of Chemistry, Molecular Horizons, University of Wollongong, New South Wales, Australia
| | - Spencer M Whitney
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| |
Collapse
|
19
|
Wilson RH, Thieulin-Pardo G, Hartl FU, Hayer-Hartl M. Improved recombinant expression and purification of functional plant Rubisco. FEBS Lett 2019; 593:611-621. [PMID: 30815863 PMCID: PMC6593764 DOI: 10.1002/1873-3468.13352] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 02/24/2019] [Accepted: 02/25/2019] [Indexed: 12/22/2022]
Abstract
Improving the performance of the key photosynthetic enzyme Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) by protein engineering is a critical strategy for increasing crop yields. The extensive chaperone requirement of plant Rubisco for folding and assembly has long been an impediment to this goal. Production of plant Rubisco in Escherichia coli requires the coexpression of the chloroplast chaperonin and four assembly factors. Here, we demonstrate that simultaneous expression of Rubisco and chaperones from a T7 promotor produces high levels of functional enzyme. Expressing the small subunit of Rubisco with a C-terminal hexahistidine-tag further improved assembly, resulting in a ~ 12-fold higher yield than the previously published procedure. The expression system described here provides a platform for the efficient production and engineering of plant Rubisco.
Collapse
Affiliation(s)
- Robert H Wilson
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Gabriel Thieulin-Pardo
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Franz-Ulrich Hartl
- Cellular Biochemistry Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Manajit Hayer-Hartl
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| |
Collapse
|
20
|
Salesse-Smith CE, Sharwood RE, Busch FA, Kromdijk J, Bardal V, Stern DB. Overexpression of Rubisco subunits with RAF1 increases Rubisco content in maize. NATURE PLANTS 2018; 4:802-810. [PMID: 30287949 DOI: 10.1038/s41477-018-0252-4] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/15/2018] [Indexed: 05/21/2023]
Abstract
Rubisco catalyses a rate-limiting step in photosynthesis and has long been a target for improvement due to its slow turnover rate. An alternative to modifying catalytic properties of Rubisco is to increase its abundance within C4 plant chloroplasts, which might increase activity and confer a higher carbon assimilation rate. Here, we overexpress the Rubisco large (LS) and small (SS) subunits with the Rubisco assembly chaperone RUBISCO ASSEMBLY FACTOR 1 (RAF1). While overexpression of LS and/or SS had no discernable impact on Rubisco content, addition of RAF1 overexpression resulted in a >30% increase in Rubisco content. Gas exchange showed a 15% increase in CO2 assimilation (ASAT) in UBI-LSSS-RAF1 transgenic plants, which correlated with increased fresh weight and in vitro Vcmax calculations. The divergence of Rubisco content and assimilation could be accounted for by the Rubisco activation state, which decreased up to 23%, suggesting that Rubisco activase may be limiting Vcmax, and impinging on the realization of photosynthetic potential from increased Rubisco content.
Collapse
Affiliation(s)
| | - Robert E Sharwood
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Florian A Busch
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Johannes Kromdijk
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | | | | |
Collapse
|
21
|
Fukayama H, Mizumoto A, Ueguchi C, Katsunuma J, Morita R, Sasayama D, Hatanaka T, Azuma T. Expression level of Rubisco activase negatively correlates with Rubisco content in transgenic rice. PHOTOSYNTHESIS RESEARCH 2018; 137:465-474. [PMID: 29846871 DOI: 10.1007/s11120-018-0525-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/25/2018] [Indexed: 05/24/2023]
Abstract
The relationship between ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase (Rca) levels was studied using transgenic rice overexpressing maize Rca (OX-mRca) and knockdown transgenic rice expressing antisense Rca (KD-Rca). The ratio of Rubisco to total soluble protein was lower in OX-mRca, whereas it was higher in KD-Rca than in WT, indicating that Rca expression was negatively correlated with Rubisco content. The expressions of other Calvin-Benson-Bassham cycle enzymes such as sedoheptulose-1,7-bisphosphatase and phosphoribulokinase analyzed by immunoblotting did not show such a negative correlation with Rca, suggesting that the effect of Rca on protein expression may be specific for Rubisco. Although Rubisco content was decreased in OX-mRca, the transcript levels of the Rubisco large subunit (OsRbcL) and the Rubisco small subunit mostly increased in OX-mRca as well as in KD-Rca. Additionally, polysome loading of OsRbcL was slightly higher in OX-mRca than it was in WT, suggesting that the OsRbcL translation activity was likely stimulated by overexpression of Rca. 35S-methionine labeling experiments demonstrated that there was no significant difference in the stability of newly synthesized Rubisco among genotypes. However, 35S-methionine-labeled Rubisco was marginally decreased in OX-mRca and increased in KD-Rca compared to the WT. These results suggest that Rca negatively affects the Rubisco content, possibly in the synthesis step.
Collapse
Affiliation(s)
- Hiroshi Fukayama
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan.
| | - Akina Mizumoto
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Chiaki Ueguchi
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Jun Katsunuma
- Laboratory of Crop Science, Faculty of Agriculture, Kobe University, Kobe, 657-8501, Japan
| | - Ryutaro Morita
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Daisuke Sasayama
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Tomoko Hatanaka
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Tetsushi Azuma
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| |
Collapse
|
22
|
Sun Q, Li YY, Wang Y, Zhao HH, Zhao TY, Zhang ZY, Li DW, Yu JL, Wang XB, Zhang YL, Han CG. Brassica yellows virus P0 protein impairs the antiviral activity of NbRAF2 in Nicotiana benthamiana. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3127-3139. [PMID: 29659986 PMCID: PMC5972614 DOI: 10.1093/jxb/ery131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/24/2018] [Indexed: 05/29/2023]
Abstract
In interactions between poleroviruses and their hosts, few cellular proteins have been identified that directly interact with the multifunctional virus P0 protein. To help explore the functions of P0, we identified a Brassica yellows virus genotype A (BrYV-A) P0BrA-interacting protein from Nicotiana benthamiana, Rubisco assembly factor 2 (NbRAF2), which localizes in the nucleus, cell periphery, chloroplasts, and stromules. We found that its C-terminal domain (amino acids 183-211) is required for self-interaction. A split ubiquitin membrane-bound yeast two-hybrid system and co-immunoprecipitation assays showed that NbRAF2 interacted with P0BrA, and co-localized in the nucleus and at the cell periphery. Interestingly, the nuclear pool of NbRAF2 decreased in the presence of P0BrA and during BrYV-A infection, and the P0BrA-mediated reduction of nuclear NbRAF2 required dual localization of NbRAF2 in the chloroplasts and nucleus. Tobacco rattle virus-based virus-induced gene silencing of NbRAF2 promoted BrYV-A infection in N. benthamiana, and the overexpression of nuclear NbRAF2 inhibited BrYV-A accumulation. Potato leafroll virus P0PL also interacted with NbRAF2 and decreased its nuclear accumulation, indicating that NbRAF2 may be a common target of poleroviruses. These results suggest that nuclear NbRAF2 possesses antiviral activity against BrYV-A infection, and that BrYV-A P0BrA interacts with NbRAF2 and alters its localization pattern to facilitate virus infection.
Collapse
Affiliation(s)
- Qian Sun
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Yuan-Yuan Li
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Ying Wang
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Hang-Hai Zhao
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Tian-Yu Zhao
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Zong-Ying Zhang
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Da-Wei Li
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Jia-Lin Yu
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Yong-Liang Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Cheng-Gui Han
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| |
Collapse
|
23
|
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a ∼530 kDa complex of 8 large (RbcL) and 8 small subunits (RbcS), mediates the fixation of atmospheric CO2 into usable sugars during photosynthesis. Despite its fundamental role, Rubisco is a remarkably inefficient enzyme and thus is produced by plants in huge amounts. It has long been a key target for bioengineering with the goal to increase crop yields. However, such efforts have been hampered by the complex requirement of Rubisco biogenesis for molecular chaperones. Recent studies have identified an array of auxiliary factors needed for the folding and assembly of the Rubisco subunits. The folding of plant RbcL subunits is mediated by the cylindrical chloroplast chaperonin, Cpn60, and its cofactor Cpn20. Folded RbcL requires a number of additional Rubisco specific assembly chaperones, including RbcX, Rubisco accumulation factors 1 (Raf1) and 2 (Raf2), and the Bundle sheath defective-2 (BSD2), to mediate the assembly of the RbcL8 intermediate complex. Incorporation of the RbcS and displacement of the assembly factors generates the active holoenzyme. An Escherichia coli strain expressing the chloroplast chaperonin and auxiliary factors now allows the expression of functional plant Rubisco, paving the way for Rubisco engineering by large scale mutagenesis. Here, we review our current understanding on how these chaperones cooperate to produce one of the most important enzymes in nature.
Collapse
Affiliation(s)
- Robert H Wilson
- 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
|
24
|
Fristedt R, Hu C, Wheatley N, Roy LM, Wachter RM, Savage L, Harbinson J, Kramer DM, Merchant SS, Yeates T, Croce R. RAF2 is a RuBisCO assembly factor in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:146-156. [PMID: 29396988 DOI: 10.1111/tpj.13849] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/22/2017] [Accepted: 01/08/2018] [Indexed: 06/07/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) catalyzes the reaction between gaseous carbon dioxide (CO2 ) and ribulose-1,5-bisphosphate. Although it is one of the most studied enzymes, the assembly mechanisms of the large hexadecameric RuBisCO is still emerging. In bacteria and in the C4 plant Zea mays, a protein with distant homology to pterin-4α-carbinolamine dehydratase (PCD) has recently been shown to be involved in RuBisCO assembly. However, studies of the homologous PCD-like protein (RAF2, RuBisCO assembly factor 2) in the C3 plant Arabidopsis thaliana (A. thaliana) have so far focused on its role in hormone and stress signaling. We investigated whether A. thalianaRAF2 is also involved in RuBisCO assembly. We localized RAF2 to the soluble chloroplast stroma and demonstrated that raf2 A. thaliana mutant plants display a severe pale green phenotype with reduced levels of stromal RuBisCO. We concluded that the RAF2 protein is probably involved in RuBisCO assembly in the C3 plant A. thaliana.
Collapse
Affiliation(s)
- Rikard Fristedt
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Chen Hu
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
| | - Nicole Wheatley
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Laura M Roy
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
| | - Rebekka M Wachter
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, AZ, USA
| | - Linda Savage
- Department of Energy Plant Research Laboratory, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - Jeremy Harbinson
- Horticulture and Product Physiology Group, Wageningen University, Wageningen, The Netherlands
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Todd Yeates
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Roberta Croce
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
25
|
Aigner H, Wilson RH, Bracher A, Calisse L, Bhat JY, Hartl FU, Hayer-Hartl M. Plant RuBisCo assembly in E. coli with five chloroplast chaperones including BSD2. Science 2018; 358:1272-1278. [PMID: 29217567 DOI: 10.1126/science.aap9221] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/17/2017] [Indexed: 01/06/2023]
Abstract
Plant RuBisCo, a complex of eight large and eight small subunits, catalyzes the fixation of CO2 in photosynthesis. The low catalytic efficiency of RuBisCo provides strong motivation to reengineer the enzyme with the goal of increasing crop yields. However, genetic manipulation has been hampered by the failure to express plant RuBisCo in a bacterial host. We achieved the functional expression of Arabidopsis thaliana RuBisCo in Escherichia coli by coexpressing multiple chloroplast chaperones. These include the chaperonins Cpn60/Cpn20, RuBisCo accumulation factors 1 and 2, RbcX, and bundle-sheath defective-2 (BSD2). Our structural and functional analysis revealed the role of BSD2 in stabilizing an end-state assembly intermediate of eight RuBisCo large subunits until the small subunits become available. The ability to produce plant RuBisCo recombinantly will facilitate efforts to improve the enzyme through mutagenesis.
Collapse
Affiliation(s)
- H Aigner
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - R H Wilson
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - A Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - L Calisse
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - J Y Bhat
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - F U Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - M Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
| |
Collapse
|
26
|
Vitlin Gruber A, Feiz L. Rubisco Assembly in the Chloroplast. Front Mol Biosci 2018; 5:24. [PMID: 29594130 PMCID: PMC5859369 DOI: 10.3389/fmolb.2018.00024] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/27/2018] [Indexed: 01/13/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step in the Calvin-Benson cycle, which transforms atmospheric carbon into a biologically useful carbon source. The slow catalytic rate of Rubisco and low substrate specificity necessitate the production of high levels of this enzyme. In order to engineer a more efficient plant Rubisco, we need to better understand its folding and assembly process. Form I Rubisco, found in green algae and vascular plants, is a hexadecamer composed of 8 large subunits (RbcL), encoded by the chloroplast genome and 8 small, nuclear-encoded subunits (RbcS). Unlike its cyanobacterial homolog, which can be reconstituted in vitro or in E. coli, assisted by bacterial chaperonins (GroEL-GroES) and the RbcX chaperone, biogenesis of functional chloroplast Rubisco requires Cpn60-Cpn20, the chloroplast homologs of GroEL-GroES, and additional auxiliary factors, including Rubisco accumulation factor 1 (Raf1), Rubisco accumulation factor 2 (Raf2) and Bundle sheath defective 2 (Bsd2). The discovery and characterization of these factors paved the way for Arabidopsis Rubisco assembly in E. coli. In the present review, we discuss the uniqueness of hetero-oligomeric chaperonin complex for RbcL folding, as well as the sequential or concurrent actions of the post-chaperonin chaperones in holoenzyme assembly. The exact stages at which each assembly factor functions are yet to be determined. Expression of Arabidopsis Rubisco in E. coli provided some insight regarding the potential roles for Raf1 and RbcX in facilitating RbcL oligomerization, for Bsd2 in stabilizing the oligomeric core prior to holoenzyme assembly, and for Raf2 in interacting with both RbcL and RbcS. In the long term, functional characterization of each known factor along with the potential discovery and characterization of additional factors will set the stage for designing more efficient plants, with a greater biomass, for use in biofuels and sustenance.
Collapse
Affiliation(s)
- Anna Vitlin Gruber
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Leila Feiz
- Boyce Thompson Institute, Cornell University, Ithaca, NY, United States
| |
Collapse
|
27
|
Doron L, Goloubinoff P, Shapira M. ZnJ2 Is a Member of a Large Chaperone Family in the Chloroplast of Photosynthetic Organisms that Features a DnaJ-Like Zn-Finger Domain. Front Mol Biosci 2018; 5:2. [PMID: 29497613 PMCID: PMC5818400 DOI: 10.3389/fmolb.2018.00002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 01/08/2018] [Indexed: 11/13/2022] Open
Abstract
Photosynthesis is performed by large complexes, composed of subunits encoded by the nuclear and chloroplast genomes. Assembly is assisted by general and target-specific chaperones, but their mode of action is yet unclear. We formerly showed that ZnJ2 is an algal chaperone resembling BSD2 from land plants. In algae, it co-migrates with the rbcL transcript on chloroplast polysomes, suggesting it contributes to the de-novo synthesis of RbcL (Doron et al., 2014). ZnJ2 contains four CXXCXGXG motifs, comprising a canonical domain typical also of DnaJ-type I (DNAJA). It contributes to the binding of protein substrates to DnaK and promotes an independent oxidoreductase activity (Mattoo et al., 2014). To examine whether ZnJ2 has oxidoreductase activity, we used the RNaseA assay, which measures the oxidation-dependent reactivation of reduced-denatured RNaseA. Although ZnJ2 assisted the native refolding of reduced-denatured RNaseA, its activity was restricted to an oxidizing environment. Thus, ZnJ2 did not carry the exclusive responsibility for the formation of disulfide bridges, but contributed to the stabilization of its target polypeptides, until they reached their native state. A ZnJ2 cysteine deficient mutant maintained a similar holding chaperone activity as the wild-type and did not induce the formation of disulfide bonds. ZnJ2 is devoid of a J-domain. It thus does not belong to the J-domain co-chaperones that target protein substrates to DnaK. As expected, in vitro, its aggregation-prevention activity was not synergic to the ATP-fueled action of DnaK/DnaJ/GrpE in assisting the native refolding of denatured malate dehydrogenase, nor did it show an independent refolding activity. A phylogenetic analysis showed that ZnJ2 and BSD2 from land plants, are two different proteins belonging to a larger group containing a cysteine-rich domain, that also includes the DNAJAs. Members of this family are apparently involved in specific assembly of photosynthetic complexes in the chloroplast.
Collapse
Affiliation(s)
- Lior Doron
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Michal Shapira
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| |
Collapse
|
28
|
Lin MT, Hanson MR. Red algal Rubisco fails to accumulate in transplastomic tobacco expressing Griffithsia monilis RbcL and RbcS genes. PLANT DIRECT 2018; 2:e00045. [PMID: 31245711 PMCID: PMC6508576 DOI: 10.1002/pld3.45] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 05/03/2023]
Abstract
In C3 plants, the carbon fixation step catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) represents a major rate-limiting step due to the competing oxygenation reaction, which leads to the energy-intensive photorespiration and lowers the overall photosynthetic efficiency. Hence, there is great biotechnological interest in replacing the Rubisco in C3 crops with a more efficient enzyme. The Rubisco enzymes from red algae are among the most attractive choices due to their remarkable preference for carboxylation over oxygenation reaction. However, the biogenesis of Rubisco is extremely complex. The Rubisco enzymes in plants, algae, and cyanobacteria are made up of eight large and eight small subunits. The folding of the large subunits and the assembly of the large subunits with the small subunits to form a functional holoenzyme require specific chaperonin complexes and assembly factors. As a result, previous success in expressing foreign Rubisco in plants has been limited to Rubisco large subunits from closely related plant species and simpler bacterial enzymes. In our previous work, we successfully replaced the Rubisco in tobacco with a cyanobacterial enzyme, which was able to support the phototrophic growth of the transgenic plants. In this work, we used the same approach to express the Rubisco subunits from the red alga Griffithsia monilis in tobacco chloroplasts in the absence of the tobacco Rubisco large subunit. Although the red algal Rubisco genes are being transcribed in tobacco chloroplasts, the transgenic plants lack functional Rubisco and can only grow in a medium containing sucrose. Our results suggest that co-expression of compatible chaperones will be necessary for successful assembly of red algal Rubisco in plants.
Collapse
Affiliation(s)
- Myat T. Lin
- Department of Molecular Biology and GeneticsCornell UniversityIthacaNYUSA
| | - Maureen R. Hanson
- Department of Molecular Biology and GeneticsCornell UniversityIthacaNYUSA
| |
Collapse
|
29
|
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: 5.5] [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
|
30
|
Affiliation(s)
- Brendon Conlan
- Australian Research Council Centre of Excellence for Translational Photosynthesis, The Australian National University, Acton, Australian Capital Territory, Australia
- Research School of Biology, College of Science, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Spencer Whitney
- Australian Research Council Centre of Excellence for Translational Photosynthesis, The Australian National University, Acton, Australian Capital Territory, Australia.
- Research School of Biology, College of Science, The Australian National University, Acton, Australian Capital Territory, Australia.
| |
Collapse
|
31
|
Affiliation(s)
- Todd O. Yeates
- University of California Los Angeles (UCLA) Department of Chemistry and Biochemistry and UCLA-DOE Institute of Genomics and Proteomics, Los Angeles, CA, USA
| | - Nicole M. Wheatley
- University of California Los Angeles (UCLA) Department of Chemistry and Biochemistry and UCLA-DOE Institute of Genomics and Proteomics, Los Angeles, CA, USA
| |
Collapse
|
32
|
Satagopan S, Sun Y, Parquette JR, Tabita FR. Synthetic CO 2-fixation enzyme cascades immobilized on self-assembled nanostructures that enhance CO 2/O 2 selectivity of RubisCO. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:175. [PMID: 28694846 PMCID: PMC5501267 DOI: 10.1186/s13068-017-0861-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/27/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND With increasing concerns over global warming and depletion of fossil-fuel reserves, it is attractive to develop innovative strategies to assimilate CO2, a greenhouse gas, into usable organic carbon. Cell-free systems can be designed to operate as catalytic platforms with enzymes that offer exceptional selectivity and efficiency, without the need to support ancillary reactions of metabolic pathways operating in intact cells. Such systems are yet to be exploited for applications involving CO2 utilization and subsequent conversion to valuable products, including biofuels. The Calvin-Benson-Bassham (CBB) cycle and the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) play a pivotal role in global CO2 fixation. RESULTS We hereby demonstrate the co-assembly of two RubisCO-associated multienzyme cascades with self-assembled synthetic amphiphilic peptide nanostructures. The immobilized enzyme cascades sequentially convert either ribose-5-phosphate (R-5-P) or glucose, a simpler substrate, to ribulose 1,5-bisphosphate (RuBP), the acceptor for incoming CO2 in the carboxylation reaction catalyzed by RubisCO. Protection from proteolytic degradation was observed in nanostructures associated with the small dimeric form of RubisCO and ancillary enzymes. Furthermore, nanostructures associated with a larger variant of RubisCO resulted in a significant enhancement of the enzyme's selectivity towards CO2, without adversely affecting the catalytic activity. CONCLUSIONS The ability to assemble a cascade of enzymes for CO2 capture using self-assembling nanostructure scaffolds with functional enhancements show promise for potentially engineering entire pathways (with RubisCO or other CO2-fixing enzymes) to redirect carbon from industrial effluents into useful bioproducts.
Collapse
Affiliation(s)
- Sriram Satagopan
- Department of Microbiology, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210-1292 USA
| | - Yuan Sun
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210-1185 USA
| | - Jon R. Parquette
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210-1185 USA
| | - F. Robert Tabita
- Department of Microbiology, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210-1292 USA
| |
Collapse
|
33
|
Mueller-Cajar O. The Diverse AAA+ Machines that Repair Inhibited Rubisco Active Sites. Front Mol Biosci 2017; 4:31. [PMID: 28580359 PMCID: PMC5437159 DOI: 10.3389/fmolb.2017.00031] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/29/2017] [Indexed: 11/13/2022] Open
Abstract
Gaseous carbon dioxide enters the biosphere almost exclusively via the active site of the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). This highly conserved catalyst has an almost universal propensity to non-productively interact with its substrate ribulose 1,5-bisphosphate, leading to the formation of dead-end inhibited complexes. In diverse autotrophic organisms this tendency has been counteracted by the recruitment of dedicated AAA+ (ATPases associated with various cellular activities) proteins that all use the energy of ATP hydrolysis to remodel inhibited Rubisco active sites leading to release of the inhibitor. Three evolutionarily distinct classes of these Rubisco activases (Rcas) have been discovered so far. Green and red-type Rca are mostly found in photosynthetic eukaryotes of the green and red plastid lineage respectively, whereas CbbQO is associated with chemoautotrophic bacteria. Ongoing mechanistic studies are elucidating how the various motors are utilizing both similar and contrasting strategies to ultimately perform their common function of cracking the inhibited Rubisco active site. The best studied mechanism utilized by red-type Rca appears to involve transient threading of the Rubisco large subunit C-terminal peptide, reminiscent of the action performed by Clp proteases. As well as providing a fascinating example of convergent molecular evolution, Rca proteins can be considered promising crop-improvement targets. Approaches aiming to replace Rubisco in plants with improved enzymes will need to ensure the presence of a compatible Rca protein. The thermolability of the Rca protein found in crop plants provides an opportunity to fortify photosynthesis against high temperature stress. Photosynthesis also appears to be limited by Rca when light conditions are fluctuating. Synthetic biology strategies aiming to enhance the autotrophic CO2 fixation machinery will need to take into consideration the requirement for Rubisco activases as well as their properties.
Collapse
Affiliation(s)
- Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological UniversitySingapore, Singapore
| |
Collapse
|
34
|
Kolesinski P, Rydzy M, Szczepaniak A. Is RAF1 protein from Synechocystis sp. PCC 6803 really needed in the cyanobacterial Rubisco assembly process? PHOTOSYNTHESIS RESEARCH 2017; 132:135-148. [PMID: 28108864 PMCID: PMC5387032 DOI: 10.1007/s11120-017-0336-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/02/2017] [Indexed: 05/29/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is responsible for carbon dioxide conversion during photosynthesis and, therefore, is the most important protein in biomass generation. Modifications of this biocatalyst toward improvements in its properties are hindered by the complicated and not yet fully understood assembly process required for the formation of active holoenzymes. An entire set of auxiliary factors, including chaperonin GroEL/GroES and assembly chaperones RbcX or Rubisco accumulation factor 1 (RAF1), is involved in the folding and subsequent assembly of Rubisco subunits. Recently, it has been shown that cyanobacterial RAF1 acts during the formation of the large Rubisco subunit (RbcL) dimer. However, both its physiological function and its necessity in the prokaryotic Rubisco formation process remain elusive. Here, we demonstrate that the Synechocystis sp. PCC 6803 strain with raf1 gene disruption shows the same growth rate as wild-type cells under standard conditions. Moreover, the Rubisco biosynthesis process seems to be unperturbed in mutant cells despite the absence of RbcL-RAF1 complexes. However, in the tested environmental conditions, sulfur starvation triggers the degradation of RbcL and subsequent proteolysis of other polypeptides in wild-type but not Δraf1 strains. Pull-down experiments also indicate that, apart from Rubisco, RAF1 co-purifies with phycocyanins. We postulate that RAF1 is not an obligatory factor in cyanobacterial Rubisco assembly, but rather participates in environmentally regulated Rubisco homeostasis.
Collapse
Affiliation(s)
- Piotr Kolesinski
- Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383, Wroclaw, Poland.
| | - Malgorzata Rydzy
- Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383, Wroclaw, Poland
| | - Andrzej Szczepaniak
- Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383, Wroclaw, Poland
| |
Collapse
|
35
|
Bracher A, Whitney SM, Hartl FU, Hayer-Hartl M. Biogenesis and Metabolic Maintenance of Rubisco. ANNUAL REVIEW OF PLANT BIOLOGY 2017; 68:29-60. [PMID: 28125284 DOI: 10.1146/annurev-arplant-043015-111633] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) mediates the fixation of atmospheric CO2 in photosynthesis by catalyzing the carboxylation of the 5-carbon sugar ribulose-1,5-bisphosphate (RuBP). Rubisco is a remarkably inefficient enzyme, fixing only 2-10 CO2 molecules per second. Efforts to increase crop yields by bioengineering Rubisco remain unsuccessful, owing in part to the complex cellular machinery required for Rubisco biogenesis and metabolic maintenance. The large subunit of Rubisco requires the chaperonin system for folding, and recent studies have shown that assembly of hexadecameric Rubisco is mediated by specific assembly chaperones. Moreover, Rubisco function can be inhibited by a range of sugar-phosphate ligands, including RuBP. Metabolic repair depends on remodeling of Rubisco by the ATP-dependent Rubisco activase and hydrolysis of inhibitory sugar phosphates by specific phosphatases. Here, we review our present understanding of the structure and function of these auxiliary factors and their utilization in efforts to engineer more catalytically efficient Rubisco enzymes.
Collapse
Affiliation(s)
- Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany ; , ,
| | - Spencer M Whitney
- Research School of Biology, Australian National University, Acton, Australian Capital Territory 2601, Australia;
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany ; , ,
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany ; , ,
| |
Collapse
|
36
|
Sharwood RE. Engineering chloroplasts to improve Rubisco catalysis: prospects for translating improvements into food and fiber crops. THE NEW PHYTOLOGIST 2017; 213:494-510. [PMID: 27935049 DOI: 10.1111/nph.14351] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 09/10/2016] [Indexed: 05/19/2023]
Abstract
494 I. 495 II. 496 III. 496 IV. 499 V. 499 VI. 501 VII. 501 VIII. 502 IX. 505 X. 506 507 References 507 SUMMARY: The uncertainty of future climate change is placing pressure on cropping systems to continue to provide stable increases in productive yields. To mitigate future climates and the increasing threats against global food security, new solutions to manipulate photosynthesis are required. This review explores the current efforts available to improve carbon assimilation within plant chloroplasts by engineering Rubisco, which catalyzes the rate-limiting step of CO2 fixation. Fixation of CO2 and subsequent cycling of 3-phosphoglycerate through the Calvin cycle provides the necessary carbohydrate building blocks for maintaining plant growth and yield, but has to compete with Rubisco oxygenation, which results in photorespiration that is energetically wasteful for plants. Engineering improvements in Rubisco is a complex challenge and requires an understanding of chloroplast gene regulatory pathways, and the intricate nature of Rubisco catalysis and biogenesis, to transplant more efficient forms of Rubisco into crops. In recent times, major advances in Rubisco engineering have been achieved through improvement of our knowledge of Rubisco synthesis and assembly, and identifying amino acid catalytic switches in the L-subunit responsible for improvements in catalysis. Improving the capacity of CO2 fixation in crops such as rice will require further advances in chloroplast bioengineering and Rubisco biogenesis.
Collapse
Affiliation(s)
- Robert E Sharwood
- ARC Center of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| |
Collapse
|
37
|
Záhonová K, Füssy Z, Oborník M, Eliáš M, Yurchenko V. RuBisCO in Non-Photosynthetic Alga Euglena longa: Divergent Features, Transcriptomic Analysis and Regulation of Complex Formation. PLoS One 2016; 11:e0158790. [PMID: 27391690 PMCID: PMC4938576 DOI: 10.1371/journal.pone.0158790] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/22/2016] [Indexed: 01/10/2023] Open
Abstract
Euglena longa, a close relative of the photosynthetic model alga Euglena gracilis, possesses an enigmatic non-photosynthetic plastid. Its genome has retained a gene for the large subunit of the enzyme RuBisCO (rbcL). Here we provide new data illuminating the putative role of RuBisCO in E. longa. We demonstrated that the E. longa RBCL protein sequence is extremely divergent compared to its homologs from the photosynthetic relatives, suggesting a possible functional shift upon the loss of photosynthesis. Similarly to E. gracilis, E. longa harbors a nuclear gene encoding the small subunit of RuBisCO (RBCS) as a precursor polyprotein comprising multiple RBCS repeats, but one of them is highly divergent. Both RBCL and the RBCS proteins are synthesized in E. longa, but their abundance is very low compared to E. gracilis. No RBCS monomers could be detected in E. longa, suggesting that processing of the precursor polyprotein is inefficient in this species. The abundance of RBCS is regulated post-transcriptionally. Indeed, blocking the cytoplasmic translation by cycloheximide has no immediate effect on the RBCS stability in photosynthetically grown E. gracilis, but in E. longa, the protein is rapidly degraded. Altogether, our results revealed signatures of evolutionary degradation (becoming defunct) of RuBisCO in E. longa and suggest that its biological role in this species may be rather unorthodox, if any.
Collapse
Affiliation(s)
- Kristína Záhonová
- Life Science Research Centre, Department of Biology and Ecology and Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 701 00 Ostrava, Czech Republic
| | - Zoltán Füssy
- Institute of Parasitology, Biology Centre ASCR, 370 05 České Budějovice, Czech Republic
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre ASCR, 370 05 České Budějovice, Czech Republic
- University of South Bohemia, Faculty of Science, 370 05 České Budějovice, Czech Republic
- Institute of Microbiology ASCR, Centrum Agaltech, 379 01 Třeboň, Czech Republic
| | - Marek Eliáš
- Life Science Research Centre, Department of Biology and Ecology and Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 701 00 Ostrava, Czech Republic
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Department of Biology and Ecology and Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 701 00 Ostrava, Czech Republic
- Institute of Parasitology, Biology Centre ASCR, 370 05 České Budějovice, Czech Republic
- * E-mail:
| |
Collapse
|
38
|
Kerfeld CA, Melnicki MR. Assembly, function and evolution of cyanobacterial carboxysomes. CURRENT OPINION IN PLANT BIOLOGY 2016; 31:66-75. [PMID: 27060669 DOI: 10.1016/j.pbi.2016.03.009] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 05/19/2023]
Abstract
All cyanobacteria contain carboxysomes, RuBisCO-encapsulating bacterial microcompartments that function as prokaryotic organelles. The two carboxysome types, alpha and beta, differ fundamentally in components, assembly, and species distribution. Alpha carboxysomes share a highly-conserved gene organization, with evidence of horizontal gene transfer from chemoautotrophic proteobacteria to the picocyanobacteria, and seem to co-assemble shells concomitantly with aggregation of cargo enzymes. In contrast, beta carboxysomes assemble an enzymatic core first, with an encapsulation peptide playing a critical role in formation of the surrounding shell. Based on similarities in assembly, and phylogenetic analysis of the pentameric shell protein conserved across all bacterial microcompartments, beta carboxysomes appear to be more closely related to the microcompartments of heterotrophic bacteria (metabolosomes) than to alpha carboxysomes, which appear deeply divergent. Beta carboxysomes can be found in the basal cyanobacterial clades that diverged before the ancestor of the chloroplast and have recently been shown to be able to encapsulate functional RuBisCO enzymes resurrected from ancestrally-reconstructed sequences, consistent with an ancient origin. Alpha and beta carboxysomes are not only distinct units of evolution, but are now emerging as genetic/metabolic modules for synthetic biology; heterologous expression and redesign of both the shell and the enzymatic core have recently been achieved.
Collapse
Affiliation(s)
- Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Matthew R Melnicki
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| |
Collapse
|
39
|
Sharwood RE, Ghannoum O, Whitney SM. Prospects for improving CO2 fixation in C3-crops through understanding C4-Rubisco biogenesis and catalytic diversity. CURRENT OPINION IN PLANT BIOLOGY 2016; 31:135-42. [PMID: 27131319 DOI: 10.1016/j.pbi.2016.04.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/30/2016] [Accepted: 04/04/2016] [Indexed: 05/09/2023]
Abstract
By operating a CO2 concentrating mechanism, C4-photosynthesis offers highly successful solutions to remedy the inefficiency of the CO2-fixing enzyme Rubisco. C4-plant Rubisco has characteristically evolved faster carboxylation rates with low CO2 affinity. Owing to high CO2 concentrations in bundle sheath chloroplasts, faster Rubisco enhances resource use efficiency in C4 plants by reducing the energy and carbon costs associated with photorespiration and lowering the nitrogen investment in Rubisco. Here, we show that C4-Rubisco from some NADP-ME species, such as maize, are also of potential benefit to C3-photosynthesis under current and future atmospheric CO2 pressures. Realizing this bioengineering endeavour necessitates improved understanding of the biogenesis requirements and catalytic variability of C4-Rubisco, as well as the development of transformation capabilities to engineer Rubisco in a wider variety of food and fibre crops.
Collapse
Affiliation(s)
- Robert E Sharwood
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, ACT 2601, Australia.
| | - Oula Ghannoum
- ARC Centre of Excellence for Translational Photosynthesis, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Spencer M Whitney
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, ACT 2601, Australia
| |
Collapse
|
40
|
Bracher A, Hauser T, Liu C, Hartl FU, Hayer-Hartl M. Structural Analysis of the Rubisco-Assembly Chaperone RbcX-II from Chlamydomonas reinhardtii. PLoS One 2015; 10:e0135448. [PMID: 26305355 PMCID: PMC4549274 DOI: 10.1371/journal.pone.0135448] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 07/22/2015] [Indexed: 01/12/2023] Open
Abstract
The most prevalent form of the Rubisco enzyme is a complex of eight catalytic large subunits (RbcL) and eight regulatory small subunits (RbcS). Rubisco biogenesis depends on the assistance by specific molecular chaperones. The assembly chaperone RbcX stabilizes the RbcL subunits after folding by chaperonin and mediates their assembly to the RbcL8 core complex, from which RbcX is displaced by RbcS to form active holoenzyme. Two isoforms of RbcX are found in eukaryotes, RbcX-I, which is more closely related to cyanobacterial RbcX, and the more distant RbcX-II. The green algae Chlamydomonas reinhardtii contains only RbcX-II isoforms, CrRbcX-IIa and CrRbcX-IIb. Here we solved the crystal structure of CrRbcX-IIa and show that it forms an arc-shaped dimer with a central hydrophobic cleft for binding the C-terminal sequence of RbcL. Like other RbcX proteins, CrRbcX-IIa supports the assembly of cyanobacterial Rubisco in vitro, albeit with reduced activity relative to cyanobacterial RbcX-I. Structural analysis of a fusion protein of CrRbcX-IIa and the C-terminal peptide of RbcL suggests that the peptide binding mode of RbcX-II may differ from that of cyanobacterial RbcX. RbcX homologs appear to have adapted to their cognate Rubisco clients as a result of co-evolution.
Collapse
Affiliation(s)
- Andreas Bracher
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
- * E-mail: (AB); (MH-H)
| | - Thomas Hauser
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Cuimin Liu
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - F. Ulrich Hartl
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
- * E-mail: (AB); (MH-H)
| |
Collapse
|
41
|
Hauser T, Bhat JY, Miličić G, Wendler P, Hartl FU, Bracher A, Hayer-Hartl M. Structure and mechanism of the Rubisco-assembly chaperone Raf1. Nat Struct Mol Biol 2015; 22:720-8. [PMID: 26237510 DOI: 10.1038/nsmb.3062] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 07/01/2015] [Indexed: 01/31/2023]
Abstract
Biogenesis of the photosynthetic enzyme Rubisco, a complex of eight large (RbcL) and eight small (RbcS) subunits, requires assembly chaperones. Here we analyzed the role of Rubisco accumulation factor1 (Raf1), a dimer of ∼40-kDa subunits. We find that Raf1 from Synechococcus elongatus acts downstream of chaperonin-assisted RbcL folding by stabilizing RbcL antiparallel dimers for assembly into RbcL8 complexes with four Raf1 dimers bound. Raf1 displacement by RbcS results in holoenzyme formation. Crystal structures show that Raf1 from Arabidopsis thaliana consists of a β-sheet dimerization domain and a flexibly linked α-helical domain. Chemical cross-linking and EM reconstruction indicate that the β-domains bind along the equator of each RbcL2 unit, and the α-helical domains embrace the top and bottom edges of RbcL2. Raf1 fulfills a role similar to that of the assembly chaperone RbcX, thus suggesting that functionally redundant factors ensure efficient Rubisco biogenesis.
Collapse
Affiliation(s)
- Thomas Hauser
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Javaid Y Bhat
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Goran Miličić
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Petra Wendler
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| |
Collapse
|
42
|
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: 74] [Impact Index Per Article: 8.2] [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
|
43
|
Whitney SM, Birch R, Kelso C, Beck JL, Kapralov MV. Improving recombinant Rubisco biogenesis, plant photosynthesis and growth by coexpressing its ancillary RAF1 chaperone. Proc Natl Acad Sci U S A 2015; 112:3564-9. [PMID: 25733857 PMCID: PMC4371954 DOI: 10.1073/pnas.1420536112] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Enabling improvements to crop yield and resource use by enhancing the catalysis of the photosynthetic CO2-fixing enzyme Rubisco has been a longstanding challenge. Efforts toward realization of this goal have been greatly assisted by advances in understanding the complexities of Rubisco's biogenesis in plastids and the development of tailored chloroplast transformation tools. Here we generate transplastomic tobacco genotypes expressing Arabidopsis Rubisco large subunits (AtL), both on their own (producing tob(AtL) plants) and with a cognate Rubisco accumulation factor 1 (AtRAF1) chaperone (producing tob(AtL-R1) plants) that has undergone parallel functional coevolution with AtL. We show AtRAF1 assembles as a dimer and is produced in tob(AtL-R1) and Arabidopsis leaves at 10-15 nmol AtRAF1 monomers per square meter. Consistent with a postchaperonin large (L)-subunit assembly role, the AtRAF1 facilitated two to threefold improvements in the amount and biogenesis rate of hybrid L8(A)S8(t) Rubisco [comprising AtL and tobacco small (S) subunits] in tob(AtL-R1) leaves compared with tob(AtL), despite >threefold lower steady-state Rubisco mRNA levels in tob(AtL-R1). Accompanying twofold increases in photosynthetic CO2-assimilation rate and plant growth were measured for tob(AtL-R1) lines. These findings highlight the importance of ancillary protein complementarity during Rubisco biogenesis in plastids, the possible constraints this has imposed on Rubisco adaptive evolution, and the likely need for such interaction specificity to be considered when optimizing recombinant Rubisco bioengineering in plants.
Collapse
Affiliation(s)
- Spencer M Whitney
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia; and
| | - Rosemary Birch
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia; and
| | - Celine Kelso
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Jennifer L Beck
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Maxim V Kapralov
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia; and
| |
Collapse
|
44
|
Belcher S, Williams-Carrier R, Stiffler N, Barkan A. Large-scale genetic analysis of chloroplast biogenesis in maize. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1004-16. [PMID: 25725436 DOI: 10.1016/j.bbabio.2015.02.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/16/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Chloroplast biogenesis involves a collaboration between several thousand nuclear genes and ~100 genes in the chloroplast. Many of the nuclear genes are of cyanobacterial ancestry and continue to perform their ancestral function. However, many others evolved subsequently and comprise a diverse set of proteins found specifically in photosynthetic eucaryotes. Genetic approaches have been key to the discovery of nuclear genes that participate in chloroplast biogenesis, especially those lacking close homologs outside the plant kingdom. SCOPE OF REVIEW This article summarizes contributions from a genetic resource in maize, the Photosynthetic Mutant Library (PML). The PML collection consists of ~2000 non-photosynthetic mutants induced by Mu transposons. We include a summary of mutant phenotypes for 20 previously unstudied maize genes, including genes encoding chloroplast ribosomal proteins, a PPR protein, tRNA synthetases, proteins involved in plastid transcription, a putative ribosome assembly factor, a chaperonin 60 isoform, and a NifU-domain protein required for Photosystem I biogenesis. MAJOR CONCLUSIONS Insertions in 94 maize genes have been linked thus far to visible and molecular phenotypes with the PML collection. The spectrum of chloroplast biogenesis genes that have been genetically characterized in maize is discussed in the context of related efforts in other organisms. This comparison shows how distinct organismal attributes facilitate the discovery of different gene classes, and reveals examples of functional divergence between monocot and dicot plants. GENERAL SIGNIFICANCE These findings elucidate the biology of an organelle whose activities are fundamental to agriculture and the biosphere. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
Collapse
Affiliation(s)
- Susan Belcher
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | | | - Nicholas Stiffler
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
| |
Collapse
|
45
|
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: 26] [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
|
46
|
Fristedt R, Williams-Carrier R, Merchant SS, Barkan A. A thylakoid membrane protein harboring a DnaJ-type zinc finger domain is required for photosystem I accumulation in plants. J Biol Chem 2014; 289:30657-30667. [PMID: 25228689 DOI: 10.1074/jbc.m114.587758] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Photosystem I (PSI) is a large pigment-protein complex and one of the two photosystems that drive electron transfer in oxygenic photosynthesis. We identified a nuclear gene required specifically for the accumulation of PSI in a forward genetic analysis of chloroplast biogenesis in maize. This gene, designated psa2, belongs to the "GreenCut" gene set, a group of genes found in green algae and plants but not in non-photosynthetic organisms. Disruption of the psa2 ortholog in Arabidopsis likewise resulted in the specific loss of PSI proteins. PSA2 harbors a conserved domain found in DnaJ chaperones where it has been shown to form a zinc finger and to have protein-disulfide isomerase activity. Accordingly, PSA2 exhibited protein-disulfide reductase activity in vitro. PSA2 localized to the thylakoid lumen and was found in a ∼250-kDa complex harboring the peripheral PSI protein PsaG but lacking several core PSI subunits. PSA2 mRNA is coexpressed with mRNAs encoding various proteins involved in the biogenesis of the photosynthetic apparatus with peak expression preceding that of genes encoding structural components. PSA2 protein abundance was not decreased in the absence of PSI but was reduced in the absence of the PSI assembly factor Ycf3. These findings suggest that a complex harboring PSA2 and PsaG mediates thiol transactions in the thylakoid lumen that are important for the assembly of PSI.
Collapse
Affiliation(s)
- Rikard Fristedt
- Department of Chemistry and Biochemistry and UCLA, Los Angeles, California 90095; Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095 and
| | | | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry and UCLA, Los Angeles, California 90095; Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095 and
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403.
| |
Collapse
|