1
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Raju AS, Kramer DM, Versaw WK. Genetically manipulated chloroplast stromal phosphate levels alter photosynthetic efficiency. PLANT PHYSIOLOGY 2024; 196:385-396. [PMID: 38701198 PMCID: PMC11376401 DOI: 10.1093/plphys/kiae241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 05/05/2024]
Abstract
The concentration of inorganic phosphate (Pi) in the chloroplast stroma must be maintained within narrow limits to sustain photosynthesis and to direct the partitioning of fixed carbon. However, it is unknown if these limits or the underlying contributions of different chloroplastic Pi transporters vary throughout the photoperiod or between chloroplasts in different leaf tissues. To address these questions, we applied live Pi imaging to Arabidopsis (Arabidopsis thaliana) wild-type plants and 2 loss-of-function transporter mutants: triose phosphate/phosphate translocator (tpt), phosphate transporter 2;1 (pht2;1), and tpt pht2;1. Our analyses revealed that stromal Pi varies spatially and temporally, and that TPT and PHT2;1 contribute to Pi import with overlapping tissue specificities. Further, the series of progressively diminished steady-state stromal Pi levels in these mutants provided the means to examine the effects of Pi on photosynthetic efficiency without imposing nutritional deprivation. ΦPSII and nonphotochemical quenching (NPQ) correlated with stromal Pi levels. However, the proton efflux activity of the ATP synthase (gH+) and the thylakoid proton motive force (pmf) were unaltered under growth conditions, but were suppressed transiently after a dark to light transition with return to wild-type levels within 2 min. These results argue against a simple substrate-level limitation of ATP synthase by depletion of stromal Pi, favoring more integrated regulatory models, which include rapid acclimation of thylakoid ATP synthase activity to reduced Pi levels.
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Affiliation(s)
| | - David M Kramer
- Department of Energy 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
- Jan IngenHousz Institute, Bornsesteeg 48A, 6708 PE Wageningen, The Netherlands
| | - Wayne K Versaw
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
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2
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Li Y, Liu Y, Ran G, Yu Y, Zhou Y, Zhu Y, Du Y, Pi L. The pentatricopeptide repeat protein DG1 promotes the transition to bilateral symmetry during Arabidopsis embryogenesis through GUN1-mediated plastid signals. THE NEW PHYTOLOGIST 2024; 244:542-557. [PMID: 39140987 DOI: 10.1111/nph.20056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 07/25/2024] [Indexed: 08/15/2024]
Abstract
During Arabidopsis embryogenesis, the transition of the embryo's symmetry from radial to bilateral between the globular and heart stage is a crucial event, involving the formation of cotyledon primordia and concurrently the establishment of a shoot apical meristem (SAM). However, a coherent framework of how this transition is achieved remains to be elucidated. In this study, we investigated the function of DELAYED GREENING 1 (DG1) in Arabidopsis embryogenesis using a newly identified dg1-3 mutant. The absence of chloroplast-localized DG1 in the mutants led to embryos being arrested at the globular or heart stage, accompanied by an expansion of WUSCHEL (WUS) and SHOOT MERISTEMLESS (STM) expression. This finding pinpoints the essential role of DG1 in regulating the transition to bilateral symmetry. Furthermore, we showed that this regulation of DG1 may not depend on its role in plastid RNA editing. Nevertheless, we demonstrated that the DG1 function in establishing bilateral symmetry is genetically mediated by GENOMES UNCOUPLED 1 (GUN1), which represses the transition process in dg1-3 embryos. Collectively, our results reveal that DG1 functionally antagonizes GUN1 to promote the transition of the Arabidopsis embryo's symmetry from radial to bilateral and highlight the role of plastid signals in regulating pattern formation during plant embryogenesis.
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Affiliation(s)
- Yajie Li
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Yiqiong Liu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Guiping Ran
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Yue Yu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Yifan Zhou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yuxian Zhu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yujuan Du
- Institute of Transformative Bio-Molecules, Nagoya University, Nagoya, 464-8601, Japan
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Limin Pi
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
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3
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Nayak N, Mehrotra R, Mehrotra S. The N-region sequence context impacts the chloroplast import efficiency of multi-TMD protein. PLANT MOLECULAR BIOLOGY 2024; 114:88. [PMID: 39093357 DOI: 10.1007/s11103-024-01485-2] [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: 01/15/2024] [Accepted: 07/04/2024] [Indexed: 08/04/2024]
Abstract
Targeting heterologous multi-transmembrane domain (TMD) proteins to plant chloroplasts requires sequences in addition to the chloroplast transit peptide (cTP). The N-terminal domain (N-region), located C-terminal to the cTP in chloroplast inner envelope membrane proteins, is an essential region for import. However, it was unclear if the N-region functions solely as a spacer sequence to facilitate cTP access or if it plays an active role in the import process. This study addresses the N-region's role by using combinations of cTPs and N-regions from Arabidopsis chloroplast inner envelope membrane proteins to direct the cyanobacterial protein SbtA to the chloroplast. We find that the sequence context of the N-region affects the chloroplast import efficiency of SbtA, with particular sequences mis-targeting the protein to different cellular sub-compartments. Additionally, specific cTP and N-region pairs exhibit varying targeting efficiencies for different heterologous proteins. Substituting individual N-region motifs did not significantly alter the chloroplast targeting efficiency of a particular cTP and N-region pair. We conclude that the N-region exhibits contextual functioning and potentially functional redundancy in motifs.
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Affiliation(s)
- Namitha Nayak
- Department of Biological Sciences, Birla Institute of Science and Technology- K. K. Birla Goa Campus, Sancoale, Goa, India
| | - Rajesh Mehrotra
- Department of Biological Sciences, Birla Institute of Science and Technology- K. K. Birla Goa Campus, Sancoale, Goa, India
| | - Sandhya Mehrotra
- Department of Biological Sciences, Birla Institute of Science and Technology- K. K. Birla Goa Campus, Sancoale, Goa, India.
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4
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Bibik JD, Sahu A, Kim B, Unda F, Andersen TB, Mansfield SD, Maravelias CT, Sharkey TD, Hamberger BR. Engineered poplar for bioproduction of the triterpene squalene. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:2301-2311. [PMID: 38507185 PMCID: PMC11258972 DOI: 10.1111/pbi.14345] [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: 08/16/2023] [Revised: 12/30/2023] [Accepted: 03/10/2024] [Indexed: 03/22/2024]
Abstract
Building sustainable platforms to produce biofuels and specialty chemicals has become an increasingly important strategy to supplement and replace fossil fuels and petrochemical-derived products. Terpenoids are the most diverse class of natural products that have many commercial roles as specialty chemicals. Poplar is a fast growing, biomassdense bioenergy crop with many species known to produce large amounts of the hemiterpene isoprene, suggesting an inherent capacity to produce significant quantities of other terpenes. Here we aimed to engineer poplar with optimized pathways to produce squalene, a triterpene commonly used in cosmetic oils, a potential biofuel candidate, and the precursor to the further diversified classes of triterpenoids and sterols. The squalene production pathways were either re-targeted from the cytosol to plastids or co-produced with lipid droplets in the cytosol. Squalene and lipid droplet co-production appeared to be toxic, which we hypothesize to be due to disruption of adventitious root formation, suggesting a need for tissue specific production. Plastidial squalene production enabled up to 0.63 mg/g fresh weight in leaf tissue, which also resulted in reductions in isoprene emission and photosynthesis. These results were also studied through a technoeconomic analysis, providing further insight into developing poplar as a production host.
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Affiliation(s)
- Jacob D. Bibik
- Cell and Molecular Biology ProgramMichigan State UniversityEast LansingMichiganUSA
- DOE Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Abira Sahu
- DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- The Plant Resilience InstituteMichigan State UniversityEast LansingMichiganUSA
| | - Boeun Kim
- DOE Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMichiganUSA
- Andlinger Center for Energy and the EnvironmentPrinceton UniversityPrincetonNew JerseyUSA
| | - Faride Unda
- DOE Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMichiganUSA
- Department of Wood Science, Faculty of ForestryUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Trine B. Andersen
- DOE Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Shawn D. Mansfield
- DOE Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMichiganUSA
- Department of Wood Science, Faculty of ForestryUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of Botany, Faculty of ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Christos T. Maravelias
- Andlinger Center for Energy and the EnvironmentPrinceton UniversityPrincetonNew JerseyUSA
- Department of Chemical and Biological EngineeringPrinceton UniversityPrincetonNew JerseyUSA
| | - Thomas D. Sharkey
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- The Plant Resilience InstituteMichigan State UniversityEast LansingMichiganUSA
| | - Björn R. Hamberger
- Cell and Molecular Biology ProgramMichigan State UniversityEast LansingMichiganUSA
- DOE Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
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5
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Bibik JD, Bryson AE, Hamberger B. Compartmentalized Terpenoid Production in Plants Using Agrobacterium-Mediated Transient Expression. Methods Mol Biol 2024; 2760:21-34. [PMID: 38468080 DOI: 10.1007/978-1-0716-3658-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
As the field of plant synthetic biology continues to grow, Agrobacterium-mediated transient expression has become an essential method to rapidly test pathway candidate genes in a combinatorial fashion. This is especially important when elucidating and engineering more complex pathways to produce commercially relevant chemicals like many terpenoids, a widely diverse class of natural products of often industrial relevance. Agrobacterium-mediated transient expression has facilitated multiplex expression of recombinant and modified enzymes, including synthetic biology approaches to compartmentalize the biosynthesis of terpenoids subcellularly. Here, we describe methods on how to deploy Agrobacterium-mediated transient expression in Nicotiana benthamiana to rapidly develop terpenoid pathways and compartmentalize terpenoid biosynthesis within plastids, the cytosol, or at the surface of lipid droplets.
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Affiliation(s)
- Jacob D Bibik
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, USA
- Current address:, MelaTech, LLC, Baltimore, Maryland, United States
| | - Abigail E Bryson
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Björn Hamberger
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, USA.
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6
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Sidorczuk K, Mackiewicz P, Pietluch F, Gagat P. Characterization of signal and transit peptides based on motif composition and taxon-specific patterns. Sci Rep 2023; 13:15751. [PMID: 37735485 PMCID: PMC10514287 DOI: 10.1038/s41598-023-42987-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/17/2023] [Indexed: 09/23/2023] Open
Abstract
Targeting peptides or presequences are N-terminal extensions of proteins that encode information about their cellular localization. They include signal peptides (SP), which target proteins to the endoplasmic reticulum, and transit peptides (TP) directing proteins to the organelles of endosymbiotic origin: chloroplasts and mitochondria. TPs were hypothesized to have evolved from antimicrobial peptides (AMPs), which are responsible for the host defence against microorganisms, including bacteria, fungi and viruses. In this study, we performed comprehensive bioinformatic analyses of amino acid motifs of targeting peptides and AMPs using a curated set of experimentally verified proteins. We identified motifs frequently occurring in each type of presequence showing specific patterns associated with their amino acid composition, and investigated their position within the presequence. We also compared motif patterns among different taxonomic groups and identified taxon-specific features, providing some evolutionary insights. Considering the functional relevance and many practical applications of targeting peptides and AMPs, we believe that our analyses will prove useful for their design, and better understanding of protein import mechanism and presequence evolution.
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Affiliation(s)
- Katarzyna Sidorczuk
- Department of Bioinformatics and Genomics, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Paweł Mackiewicz
- Department of Bioinformatics and Genomics, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Filip Pietluch
- Department of Bioinformatics and Genomics, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Przemysław Gagat
- Department of Bioinformatics and Genomics, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland.
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Sun AZ, Chen JH, Jin XQ, Li H, Guo FQ. Supplementing the Nuclear-Encoded PSII Subunit D1 Induces Dramatic Metabolic Reprogramming in Flag Leaves during Grain Filling in Rice. PLANTS (BASEL, SWITZERLAND) 2023; 12:3009. [PMID: 37631220 PMCID: PMC10458752 DOI: 10.3390/plants12163009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023]
Abstract
Our previous study has demonstrated that the nuclear-origin supplementation of the PSII core subunit D1 protein stimulates growth and increases grain yields in transgenic rice plants by enhancing photosynthetic efficiency. In this study, the underlying mechanisms have been explored regarding how the enhanced photosynthetic capacity affects metabolic activities in the transgenic plants of rice harboring the integrated transgene RbcSPTP-OspsbA cDNA, cloned from rice, under control of the AtHsfA2 promoter and N-terminal fused with the plastid-transit peptide sequence (PTP) cloned from the AtRbcS. Here, a comparative metabolomic analysis was performed using LC-MS in flag leaves of the transgenic rice plants during the grain-filling stage. Critically, the dramatic reduction in the quantities of nucleotides and certain free amino acids was detected, suggesting that the increased photosynthetic assimilation and grain yield in the transgenic plants correlates with the reduced contents of free nucleotides and the amino acids such as glutamine and glutamic acid, which are cellular nitrogen sources. These results suggest that enhanced photosynthesis needs consuming more free nucleotides and nitrogen sources to support the increase in biomass and yields, as exhibited in transgenic rice plants. Unexpectedly, dramatic changes were measured in the contents of flavonoids in the flag leaves, suggesting that a tight and coordinated relationship exists between increasing photosynthetic assimilation and flavonoid biosynthesis. Consistent with the enhanced photosynthetic efficiency, the substantial increase was measured in the content of starch, which is the primary product of the Calvin-Benson cycle, in the transgenic rice plants under field growth conditions.
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Affiliation(s)
- Ai-Zhen Sun
- The National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (A.-Z.S.); (J.-H.C.); (X.-Q.J.); (H.L.)
| | - Juan-Hua Chen
- The National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (A.-Z.S.); (J.-H.C.); (X.-Q.J.); (H.L.)
| | - Xue-Qi Jin
- The National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (A.-Z.S.); (J.-H.C.); (X.-Q.J.); (H.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Han Li
- The National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (A.-Z.S.); (J.-H.C.); (X.-Q.J.); (H.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fang-Qing Guo
- The National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (A.-Z.S.); (J.-H.C.); (X.-Q.J.); (H.L.)
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8
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Choi YJ, Geem KR, Kim J, Lee DW. Differential contributions of two domains of NAI2 to the formation of the endoplasmic reticulum body. FRONTIERS IN PLANT SCIENCE 2023; 14:1184678. [PMID: 37346116 PMCID: PMC10279885 DOI: 10.3389/fpls.2023.1184678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 05/22/2023] [Indexed: 06/23/2023]
Abstract
The endoplasmic reticulum (ER) serves essential functions in eukaryotic cells, including protein folding, transport of secretory proteins, and lipid synthesis. The ER is a highly dynamic organelle that generates various types of compartments. Among them, the ER body is specifically present in plants in the Brassicaceae family and plays a crucial role in chemical defense against pathogens. The NAI2 protein is essential for ER body formation, and its ectopic overexpression is sufficient to induce ER body formation even in the leaves of Nicotiana benthamiana, where the ER body does not naturally exist. Despite the significance of NAI2 in ER body formation, the mechanism whereby NAI2 mediates ER body formation is not fully clear. This study aimed to investigate how two domains of Arabidopsis NAI2, the Glu-Phe-Glu (EFE) domain (ED) and the NAI2 domain (ND), contribute to ER body formation in N. benthamiana leaves. Using co-immunoprecipitation and bimolecular fluorescence complementation assays, we found that the ND is critical for homomeric interaction of NAI2 and ER body formation. Moreover, deletion of ED induced the formation of enlarged ER bodies, suggesting that ED plays a regulatory role during ER body formation. Our results indicate that the two domains of NAI2 cooperate to induce ER body formation in a balanced manner.
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Affiliation(s)
- Yun Ju Choi
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, Republic of Korea
| | - Kyoung Rok Geem
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Jitae Kim
- Bio-Energy Research Center, Chonnam National University, Gwangju, Republic of Korea
| | - Dong Wook Lee
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, Republic of Korea
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, Republic of Korea
- Kumho Life Science Laboratory, Chonnam National University, Gwangju, Republic of Korea
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9
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Ballabani G, Forough M, Kessler F, Shanmugabalaji V. The journey of preproteins across the chloroplast membrane systems. Front Physiol 2023; 14:1213866. [PMID: 37324391 PMCID: PMC10267391 DOI: 10.3389/fphys.2023.1213866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 05/22/2023] [Indexed: 06/17/2023] Open
Abstract
The photosynthetic capacity of chloroplasts is vital for autotrophic growth in algae and plants. The origin of the chloroplast has been explained by the endosymbiotic theory that proposes the engulfment of a cyanobacterium by an ancestral eukaryotic cell followed by the transfer of many cyanobacterial genes to the host nucleus. As a result of the gene transfer, the now nuclear-encoded proteins acquired chloroplast targeting peptides (known as transit peptides; transit peptide) and are translated as preproteins in the cytosol. Transit peptides contain specific motifs and domains initially recognized by cytosolic factors followed by the chloroplast import components at the outer and inner envelope of the chloroplast membrane. Once the preprotein emerges on the stromal side of the chloroplast protein import machinery, the transit peptide is cleaved by stromal processing peptidase. In the case of thylakoid-localized proteins, cleavage of the transit peptides may expose a second targeting signal guiding the protein to the thylakoid lumen or allow insertion into the thylakoid membrane by internal sequence information. This review summarizes the common features of targeting sequences and describes their role in routing preproteins to and across the chloroplast envelope as well as the thylakoid membrane and lumen.
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Affiliation(s)
| | | | - Felix Kessler
- *Correspondence: Felix Kessler, ; Venkatasalam Shanmugabalaji,
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10
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Fu ZW, Feng YR, Gao X, Ding F, Li JH, Yuan TT, Lu YT. Salt stress-induced chloroplastic hydrogen peroxide stimulates pdTPI sulfenylation and methylglyoxal accumulation. THE PLANT CELL 2023; 35:1593-1616. [PMID: 36695476 PMCID: PMC10118271 DOI: 10.1093/plcell/koad019] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/24/2023] [Indexed: 06/17/2023]
Abstract
High salinity, an adverse environmental factor affecting about 20% of irrigated arable land worldwide, inhibits plant growth and development by causing oxidative stress, damaging cellular components, and disturbing global metabolism. However, whether and how reactive oxygen species disturb the metabolism of salt-stressed plants remain elusive. Here, we report that salt-induced hydrogen peroxide (H2O2) inhibits the activity of plastid triose phosphate isomerase (pdTPI) to promote methylglyoxal (MG) accumulation and stimulates the sulfenylation of pdTPI at cysteine 74. We also show that MG is a key factor limiting the plant growth, as a decrease in MG levels completely rescued the stunted growth and repressed salt stress tolerance of the pdtpi mutant. Furthermore, targeting CATALASE 2 into chloroplasts to prevent salt-induced overaccumulation of H2O2 conferred salt stress tolerance, revealing a role for chloroplastic H2O2 in salt-caused plant damage. In addition, we demonstrate that the H2O2-mediated accumulation of MG in turn induces H2O2 production, thus forming a regulatory loop that further inhibits the pdTPI activity in salt-stressed plants. Our findings, therefore, illustrate how salt stress induces MG production to inhibit the plant growth.
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Affiliation(s)
- Zheng-Wei Fu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Yu-Rui Feng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Xiang Gao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Feng Ding
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Jian-Hui Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Ting-Ting Yuan
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Ying-Tang Lu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
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11
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Muthamilselvan T, Khan MRI, Hwang I. Assembly of Human Papillomavirus 16 L1 Protein in Nicotiana benthamiana Chloroplasts into Highly Immunogenic Virus-Like Particles. JOURNAL OF PLANT BIOLOGY = SINGMUL HAKHOE CHI 2023; 66:1-10. [PMID: 37360984 PMCID: PMC10078042 DOI: 10.1007/s12374-023-09393-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/05/2023] [Accepted: 03/17/2023] [Indexed: 06/28/2023]
Abstract
Infection with human papillomavirus (HPV) can cause cervical cancers in women, and vaccination against the virus is one of most effective ways to prevent these cancers. Two vaccines made of virus-like particles (VLPs) of HPV L1 proteins are currently commercially available. However, these HPV vaccines are highly expensive, and thus not affordable for women living in developing countries. Therefore, great demand exists to produce a cost-effective vaccine. Here, we investigate the production of self-assembled HPV16 VLPs in plants. We generated a chimeric protein composed of N-terminal 79 amino acid residues of RbcS as a long-transit peptide to target chloroplasts, the SUMO domain, and HPV16 L1 proteins. The chimeric gene was expressed in plants with chloroplast-targeted bdSENP1, a protein that specifically recognizes the SUMO domain and cleaves its cleavage site. This co-expression of bdSENP1 led to the release of HPV16 L1 from the chimeric proteins without any extra amino acid residues. HPV16 L1 purified by heparin chromatography formed VLPs that mimicked native virions. Moreover, the plant-produced HPV16 L1 VLPs elicited strong immune responses in mice without adjuvants. Thus, we demonstrated the cost-effective production of HPV16 VLPs in plants. Supplementary Information The online version contains supplementary material available at 10.1007/s12374-023-09393-6.
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Affiliation(s)
| | - Md Rezaul Islam Khan
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673 Korea
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12
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Lee J, Moon B, Lee DW, Hwang I. Translation rate underpins specific targeting of N-terminal transmembrane proteins to mitochondria. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023. [PMID: 36897023 DOI: 10.1111/jipb.13475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
Protein biogenesis is a complex process, and complexity is greatly increased in eukaryotic cells through specific targeting of proteins to different organelles. To direct targeting, organellar proteins carry an organelle-specific targeting signal for recognition by organelle-specific import machinery. However, the situation is confusing for transmembrane domain (TMD)-containing signal-anchored (SA) proteins of various organelles because TMDs function as an endoplasmic reticulum (ER) targeting signal. Although ER targeting of SA proteins is well understood, how they are targeted to mitochondria and chloroplasts remains elusive. Here, we investigated how the targeting specificity of SA proteins is determined for specific targeting to mitochondria and chloroplasts. Mitochondrial targeting requires multiple motifs around and within TMDs: a basic residue and an arginine-rich region flanking the N- and C-termini of TMDs, respectively, and an aromatic residue in the C-terminal side of the TMD that specify mitochondrial targeting in an additive manner. These motifs play a role in slowing down the elongation speed during translation, thereby ensuring mitochondrial targeting in a co-translational manner. By contrast, the absence of any of these motifs individually or together causes at varying degrees chloroplast targeting that occurs in a post-translational manner.
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Affiliation(s)
- Junho Lee
- Department of Life Science, Pohang University of Science and Technology, Pohang, 790-784, South Korea
| | - Byeongho Moon
- Department of Life Science, Pohang University of Science and Technology, Pohang, 790-784, South Korea
| | - Dong Wook Lee
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, South Korea
- Department Bioenergy Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Inhwan Hwang
- Department of Life Science, Pohang University of Science and Technology, Pohang, 790-784, South Korea
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13
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Kim DB, Na C, Hwang I, Lee DW. Understanding protein translocation across chloroplast membranes: Translocons and motor proteins. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:408-416. [PMID: 36223071 DOI: 10.1111/jipb.13385] [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: 08/29/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Subcellular organelles in eukaryotes are surrounded by lipid membranes. In an endomembrane system, vesicle trafficking is the primary mechanism for the delivery of organellar proteins to specific organelles. However, organellar proteins for chloroplasts, mitochondria, the nucleus, and peroxisomes that are translated in the cytosol are directly imported into their target organelles. Chloroplasts are a plant-specific organelle with outer and inner envelope membranes, a dual-membrane structure that is similar to mitochondria. Interior chloroplast proteins translated by cytosolic ribosomes are thus translocated through TOC and TIC complexes (translocons in the outer and inner envelope of chloroplasts, respectively), with stromal ATPase motor proteins playing a critical role in pulling pre-proteins through these import channels. Over the last three decades, the identity and function of TOC/TIC components and stromal motor proteins have been actively investigated, which has shed light on the action mechanisms at a molecular level. However, there remains some disagreement over the exact composition of TIC complexes and genuine stromal motor proteins. In this review, we discuss recent findings on the mechanisms by which proteins are translocated through TOC/TIC complexes and discuss future prospects for this field of research.
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Affiliation(s)
- Da Been Kim
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, Korea
| | - Changhee Na
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, Korea
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Dong Wook Lee
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, Korea
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, 61186, Korea
- Kumho Life Science Laboratory, Chonnam National University, Gwangju, 61186, Korea
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14
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Gao LL, Hong ZH, Wang Y, Wu GZ. Chloroplast proteostasis: A story of birth, life, and death. PLANT COMMUNICATIONS 2023; 4:100424. [PMID: 35964157 PMCID: PMC9860172 DOI: 10.1016/j.xplc.2022.100424] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/02/2022] [Accepted: 08/10/2022] [Indexed: 06/02/2023]
Abstract
Protein homeostasis (proteostasis) is a dynamic balance of protein synthesis and degradation. Because of the endosymbiotic origin of chloroplasts and the massive transfer of their genetic information to the nucleus of the host cell, many protein complexes in the chloroplasts are constituted from subunits encoded by both genomes. Hence, the proper function of chloroplasts relies on the coordinated expression of chloroplast- and nucleus-encoded genes. The biogenesis and maintenance of chloroplast proteostasis are dependent on synthesis of chloroplast-encoded proteins, import of nucleus-encoded chloroplast proteins from the cytosol, and clearance of damaged or otherwise undesired "old" proteins. This review focuses on the regulation of chloroplast proteostasis, its interaction with proteostasis of the cytosol, and its retrograde control over nuclear gene expression. We also discuss significant issues and perspectives for future studies and potential applications for improving the photosynthetic performance and stress tolerance of crops.
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Affiliation(s)
- Lin-Lin Gao
- Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Zheng-Hui Hong
- Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yinsong Wang
- Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Guo-Zhang Wu
- Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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15
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Liu Y, Li M, Yu J, Ma A, Wang J, Yun DJ, Xu ZY. Plasma membrane-localized Hsp40/DNAJ chaperone protein facilitates OsSUVH7-OsBAG4-OsMYB106 transcriptional complex formation for OsHKT1;5 activation. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:265-279. [PMID: 36349953 DOI: 10.1111/jipb.13403] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
The salinization of irrigated land affects agricultural productivity. HIGH-AFFINITY POTASSIUM (K+ ) TRANSPORTER 1;5 (OsHKT1;5)-dependent sodium (Na+ ) transport is a key salt tolerance mechanism during rice growth and development. Using a previously generated high-throughput activation tagging-based T-DNA insertion mutant pool, we isolated a mutant exhibiting salt stress-sensitive phenotype, caused by a reduction in OsHKT1;5 transcripts. The salt stress-sensitive phenotype of this mutant results from the loss of function of OsDNAJ15, which encodes plasma membrane-localized heat shock protein 40 (Hsp40). osdnaj15 loss-of-function mutants show decreased plant height, increased leaf angle, and reduced grain number caused by shorter panicle length and fewer branches. On the other h'and, OsDNAJ15-overexpression plants showed salt stress-tolerant phenotypes. Intriguingly, salt stress facilitates the nuclear relocation of OsDNAJ15 so that it can interact with OsBAG4, and OsDNAJ15 and OsBAG4 synergistically facilitate the DNA-binding activity of OsMYB106 to positively regulate the expression of OsHKT1;5. Overall, our results reveal a novel function of plasma membrane-localized Hsp40 protein in modulating, alongside chaperon regulator OsBAG4, transcriptional regulation under salinity stress tolerance.
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Affiliation(s)
- Yutong Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Mengting Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Jinlei Yu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Ao Ma
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Jie Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Dae-Jin Yun
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
| | - Zheng-Yi Xu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
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16
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Chen ZF, Wang TH, Feng CY, Guo HF, Guan XX, Zhang TL, Li WZ, Xing GM, Sun S, Tan GF. Multigene manipulation of photosynthetic carbon metabolism enhances the photosynthetic capacity and biomass yield of cucumber under low-CO 2 environment. FRONTIERS IN PLANT SCIENCE 2022; 13:1005261. [PMID: 36330244 PMCID: PMC9623318 DOI: 10.3389/fpls.2022.1005261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Solar greenhouses are important in the vegetable production and widely used for the counter-season production in the world. However, the CO2 consumed by crops for photosynthesis after sunrise is not supplemented and becomes chronically deficient due to the airtight structure of solar greenhouses. Vegetable crops cannot effectively utilize light resources under low-CO2 environment, and this incapability results in reduced photosynthetic efficiency and crop yield. We used cucumber as a model plant and generated several sets of transgenic cucumber plants overexpressing individual genes, including β-carbonic anhydrase 1 (CsβCA1), β-carbonic anhydrase 4 (CsβCA4), and sedoheptulose-1,7-bisphosphatase (CsSBP); fructose-1,6-bisphosphate aldolase (CsFBA), and CsβCA1 co-expressing plants; CsβCA4, CsSBP, and CsFBA co-expressing plants (14SF). The results showed that the overexpression of CsβCA1, CsβCA4, and 14SF exhibited higher photosynthetic and biomass yield in transgenic cucumber plants under low-CO2 environment. Further enhancements in photosynthesis and biomass yield were observed in 14SF transgenic plants under low-CO2 environment. The net photosynthesis biomass yield and photosynthetic rate increased by 49% and 79% compared with those of the WT. However, the transgenic cucumbers of overexpressing CsFBA and CsSBP showed insignificant differences in photosynthesis and biomass yield compared with the WT under low-CO2.environment. Photosynthesis, fluorescence parameters, and enzymatic measurements indicated that CsβCA1, CsβCA4, CsSBP, and CsFBA had cumulative effects in photosynthetic carbon assimilation under low-CO2 environment. Co-expression of this four genes (CsβCA1, CsβCA4, CsSBP, and CsFBA) can increase the carboxylation activity of RuBisCO and promote the regeneration of RuBP. As a result, the 14SF transgenic plants showed a higher net photosynthetic rate and biomass yield even under low-CO2environment.These findings demonstrate the possibility of cultivating crops with high photosynthetic efficiency by manipulating genes involved in the photosynthetic carbon assimilation metabolic pathway.
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Affiliation(s)
- Zhi-Feng Chen
- College of Biology and Agricultural Technology, Zunyi Normal College, Zunyi, China
| | - Tian-Hong Wang
- Fruit and Vegetable Research Institute, Academy of Agricultural Sciences, Zunyi, China
| | - Chao-Yang Feng
- College of Biology and Agricultural Technology, Zunyi Normal College, Zunyi, China
| | - Hai-Feng Guo
- College of Biology and Agricultural Technology, Zunyi Normal College, Zunyi, China
| | - Xiao-Xi Guan
- College of Biology and Agricultural Technology, Zunyi Normal College, Zunyi, China
| | - Tian-Li Zhang
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
| | - Wen-Zhao Li
- College of Biology and Agricultural Technology, Zunyi Normal College, Zunyi, China
| | - Guo-Ming Xing
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
| | - Sheng Sun
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
| | - Guo-Fei Tan
- Institute of Horticulture, Guizhou Academy of Agricultural Sciences, Guiyang, China
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17
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Jeong J, Moon B, Hwang I, Lee DW. GREEN FLUORESCENT PROTEIN variants with enhanced folding are more efficiently imported into chloroplasts. PLANT PHYSIOLOGY 2022; 190:238-249. [PMID: 35699510 PMCID: PMC9434181 DOI: 10.1093/plphys/kiac291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/05/2022] [Indexed: 06/15/2023]
Abstract
Chloroplasts and mitochondria are subcellular organelles that evolved from cyanobacteria and α-proteobacteria, respectively. Although they have their own genomes, the majority of their proteins are encoded by nuclear genes, translated by cytosolic ribosomes, and imported via outer and inner membrane translocon complexes. The unfolding of mature regions of proteins is thought to be a prerequisite for the import of the proteins into these organelles. However, it is not fully understood how protein folding properties affect their import into these organelles. In this study, we examined the import behavior of chloroplast and mitochondrial reporters with normal green fluorescent protein (GFP) and two GFP variants with enhanced folding propensity, superfolder GFP (sfGFP) and extra-superfolder GFP (esGFP), which is folded better than sfGFP. sfGFP and esGFP were less dependent on the sequence motifs of the transit peptide (TP) and import machinery during protein import into Arabidopsis (Arabidopsis thaliana) chloroplasts, compared with normal GFP. sfGFP and esGFP were efficiently imported into chloroplasts by a mutant TP with an alanine substitution in the N-terminal MLM motif, whereas the same mutant TP showed a defect in importing normal GFP into chloroplasts. Moreover, sfGFP and esGFP were efficiently imported into plastid protein import 2 (ppi2) and heat shock protein 93-V (hsp93-V) plants, which have mutations in atToc159 and Hsp93-V, respectively. In contrast, the presequence-mediated mitochondrial import of sfGFP and esGFP was severely impaired. Based on these results, we propose that the chloroplast import machinery is more tolerant to different folding states of preproteins, whereas the mitochondrial machinery is more specialized in the translocation of unfolded preproteins.
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Affiliation(s)
- Jinseung Jeong
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju 61186, South Korea
| | - Byeongho Moon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, South Korea
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18
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Woo S, Moon B, Hwang I. Both metaxin and Tom20 together with two mitochondria-specific motifs support mitochondrial targeting of dual-targeting AtSufE1. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:1596-1613. [PMID: 35713200 DOI: 10.1111/jipb.13312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Plant cells have two endosymbiotic organelles, chloroplasts, and mitochondria. These organelles perform specific functions that depend on organelle-specific proteins. The majority of chloroplast and mitochondrial proteins are specifically imported by the transit peptide and presequence, respectively. However, a significant number of proteins are also dually targeted to these two organelles. Currently, it is not fully understood how proteins are dually targeted to both chloroplasts and mitochondria. In this study, the mechanism underlying mitochondrial targeting of dual targeting AtSufE1 in Arabidopsis was elucidated. The N-terminal fragment containing 80 residues of AtSufE1 (AtSufE1N80) was sufficient to confer dual targeting of reporter protein, AtSufE1N80:GFP, in protoplasts. Two sequence motifs, two arginine residues at 15th and 21st positions, and amino acid (aa) sequence motif AKTLLLRPLK from the 31st to 40th aa position, were responsible for targeting to mitochondria a portion of reporter proteins amid the chloroplast targeting. The sequence motif PSEVPFRRT from the 41st to 50th aa position constitutes a common motif for targeting to both chloroplasts and mitochondria. For mitochondrial import of AtSufE1:N80, Metaxin played a critical role. In addition, BiFC and protein pull-down experiments showed that AtSufE1N80 specifically interacts with import receptors, Metaxin and Tom20. The interaction of AtSufE1N80 with Metaxin was required for the interaction with Tom20. Based on these results, we propose that mitochondrial targeting of dual-targeting AtSufE1 is mediated by both mitochondria-specific and common sequence motifs in the signal sequence through the interaction with import receptors, Metaxin and Tom20, in a successive manner.
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Affiliation(s)
- Seungjin Woo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Byeongho Moon
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 790-784, Korea
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19
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Bibik JD, Weraduwage SM, Banerjee A, Robertson K, Espinoza-Corral R, Sharkey TD, Lundquist PK, Hamberger BR. Pathway Engineering, Re-targeting, and Synthetic Scaffolding Improve the Production of Squalene in Plants. ACS Synth Biol 2022; 11:2121-2133. [PMID: 35549088 PMCID: PMC9208017 DOI: 10.1021/acssynbio.2c00051] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Plants are increasingly becoming an option for sustainable bioproduction of chemicals and complex molecules like terpenoids. The triterpene squalene has a variety of biotechnological uses and is the precursor to a diverse array of triterpenoids, but we currently lack a sustainable strategy to produce large quantities for industrial applications. Here, we further establish engineered plants as a platform for production of squalene through pathway re-targeting and membrane scaffolding. The squalene biosynthetic pathway, which natively resides in the cytosol and endoplasmic reticulum, was re-targeted to plastids, where screening of diverse variants of enzymes at key steps improved squalene yields. The highest yielding enzymes were used to create biosynthetic scaffolds on co-engineered, cytosolic lipid droplets, resulting in squalene yields up to 0.58 mg/gFW or 318% higher than a cytosolic pathway without scaffolding during transient expression. These scaffolds were also re-targeted to plastids where they associated with membranes throughout, including the formation of plastoglobules or plastidial lipid droplets. Plastid scaffolding ameliorated the negative effects of squalene biosynthesis and showed up to 345% higher rates of photosynthesis than without scaffolding. This study establishes a platform for engineering the production of squalene in plants, providing the opportunity to expand future work into production of higher-value triterpenoids.
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Affiliation(s)
- Jacob D. Bibik
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824, United States
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Sarathi M. Weraduwage
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
| | - Aparajita Banerjee
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Ka’shawn Robertson
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, United States
| | - Roberto Espinoza-Corral
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- The Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, United States
| | - Thomas D. Sharkey
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- The Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, United States
| | - Peter K. Lundquist
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- The Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, United States
| | - Björn R. Hamberger
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824, United States
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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20
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Jeong J, Hwang I, Lee DW. Functional Organization of Sequence Motifs in Diverse Transit Peptides of Chloroplast Proteins. Front Physiol 2021; 12:795156. [PMID: 34880786 PMCID: PMC8645953 DOI: 10.3389/fphys.2021.795156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/28/2021] [Indexed: 11/17/2022] Open
Abstract
Although the chloroplasts in plants are characterized by an inherent genome, the chloroplast proteome is composed of proteins encoded by not only the chloroplast genome but also the nuclear genome. Nuclear-encoded chloroplast proteins are synthesized on cytosolic ribosomes and post-translationally targeted to the chloroplasts. In the latter process, an N-terminal cleavable transit peptide serves as a targeting signal required for the import of nuclear-encoded chloroplast interior proteins. This import process is mediated via an interaction between the sequence motifs in transit peptides and the components of the TOC/TIC (translocon at the outer/inner envelope of chloroplasts) translocons. Despite a considerable diversity in primary structures, several common features have been identified among transit peptides, including N-terminal moderate hydrophobicity, multiple proline residues dispersed throughout the transit peptide, preferential usage of basic residues over acidic residues, and an absence of N-terminal arginine residues. In this review, we will recapitulate and discuss recent progress in our current understanding of the functional organization of sequence elements commonly present in diverse transit peptides, which are essential for the multi-step import of chloroplast proteins.
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Affiliation(s)
- Jinseung Jeong
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Dong Wook Lee
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea.,Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, South Korea
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21
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Ishikawa Y, Cassan C, Kadeer A, Yuasa K, Sato N, Sonoike K, Kaneko Y, Miyagi A, Takahashi H, Ishikawa T, Yamaguchi M, Nishiyama Y, Hihara Y, Gibon Y, Kawai-Yamada M. The NAD Kinase Slr0400 Functions as a Growth Repressor in Synechocystis sp. PCC 6803. PLANT & CELL PHYSIOLOGY 2021; 62:668-677. [PMID: 33560438 DOI: 10.1093/pcp/pcab023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
NADP+, the phosphorylated form of nicotinamide adenine dinucleotide (NAD), plays an essential role in many cellular processes. NAD kinase (NADK), which is conserved in all living organisms, catalyzes the phosphorylation of NAD+ to NADP+. However, the physiological role of phosphorylation of NAD+ to NADP+ in the cyanobacterium Synechocystis remains unclear. In this study, we report that slr0400, an NADK-encoding gene in Synechocystis, functions as a growth repressor under light-activated heterotrophic growth conditions and light and dark cycle conditions in the presence of glucose. We show, via characterization of NAD(P)(H) content and enzyme activity, that NAD+ accumulation in slr0400-deficient mutant results in the unsuppressed activity of glycolysis and tricarboxylic acid (TCA) cycle enzymes. In determining whether Slr0400 functions as a typical NADK, we found that constitutive expression of slr0400 in an Arabidopsis nadk2-mutant background complements the pale-green phenotype. Moreover, to determine the physiological background behind the growth advantage of mutants lacking slr04000, we investigated the photobleaching phenotype of slr0400-deficient mutant under high-light conditions. Photosynthetic analysis found in the slr0400-deficient mutant resulted from malfunctions in the Photosystem II (PSII) photosynthetic machinery. Overall, our results suggest that NADP(H)/NAD(H) maintenance by slr0400 plays a significant role in modulating glycolysis and the TCA cycle to repress the growth rate and maintain the photosynthetic capacity.
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Affiliation(s)
- Yuuma Ishikawa
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601 Japan
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Cedric Cassan
- UMR1332 Biologie du Fruit et Pathologie and Plateforme Métabolome, Centre de Génomique Fonctionnelle Bordeaux, INRA-Bordeaux and Bordeaux University, Villenave d'Ornon, France
| | - Aikeranmu Kadeer
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Koki Yuasa
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Nozomu Sato
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Kintake Sonoike
- Faculty of Education and Integrated Arts and Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480 Japan
| | - Yasuko Kaneko
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Atsuko Miyagi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Hiroko Takahashi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Toshiki Ishikawa
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Masatoshi Yamaguchi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Yoshitaka Nishiyama
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
| | - Yves Gibon
- UMR1332 Biologie du Fruit et Pathologie and Plateforme Métabolome, Centre de Génomique Fonctionnelle Bordeaux, INRA-Bordeaux and Bordeaux University, Villenave d'Ornon, France
| | - Maki Kawai-Yamada
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570 Japan
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22
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Lee DW, Hwang I. Understanding the evolution of endosymbiotic organelles based on the targeting sequences of organellar proteins. THE NEW PHYTOLOGIST 2021; 230:924-930. [PMID: 33404103 DOI: 10.1111/nph.17167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/14/2020] [Indexed: 05/17/2023]
Abstract
Organellogenesis, a key aspect of eukaryotic cell evolution, critically depends on the successful establishment of organellar protein import mechanisms. Phylogenetic analysis revealed that the evolution of the two endosymbiotic organelles, the mitochondrion and the chloroplast, is thought to have occurred at time periods far from each other. Despite this, chloroplasts and mitochondria have highly similar protein import mechanisms. This raises intriguing questions such as what underlies such similarity in the import mechanisms and how these similar mechanisms have evolved. In this review, we summarise the recent findings regarding sorting and specific targeting of these organellar proteins. Based on these findings, we propose possible evolutionary scenarios regarding how the signal sequences of chloroplasts and mitochondrial proteins ended up having such relationship.
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Affiliation(s)
- Dong Wook Lee
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, Korea
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, 61186, Korea
- Kumho Life Science Laboratory, Chonnam National University, Gwangju, 61186, Korea
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, 100083, China
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Fu X, Zhang F, Ma Y, Hassani D, Peng B, Pan Q, Zhang Y, Deng Z, Liu W, Zhang J, Han L, Chen D, Zhao J, Li L, Sun X, Tang K. High-Level Patchoulol Biosynthesis in Artemisia annua L. Front Bioeng Biotechnol 2021; 8:621127. [PMID: 33614607 PMCID: PMC7890116 DOI: 10.3389/fbioe.2020.621127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 12/30/2020] [Indexed: 11/13/2022] Open
Abstract
Terpenes constitute the largest class of secondary metabolites in plants. Some terpenes are essential for plant growth and development, membrane components, and photosynthesis. Terpenes are also economically useful for industry, agriculture, and pharmaceuticals. However, there is very low content of most terpenes in microbes and plants. Chemical or microbial synthesis of terpenes are often costly. Plants have the elaborate and economic biosynthetic way of producing high-value terpenes through photosynthesis. Here we engineered the heterogenous sesquiterpenoid patchoulol production in A. annua. When using a strong promoter such as 35S to over express the avian farnesyl diphosphate synthase gene and patchoulol synthase gene, the highest content of patchoulol was 52.58 μg/g DW in transgenic plants. When altering the subcellular location of the introduced sesquiterpene synthetase via a signal peptide, the accumulation of patchoulol was observably increased to 273 μg/g DW. This case demonstrates that A. annua plant with glandular trichomes is a useful platform for synthetic biology studies.
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Affiliation(s)
- Xueqing Fu
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Fangyuan Zhang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.,Southwest University-Tibet Agriculture and Animal Husbandry College (SWU-TAAHC) Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, China
| | - Yanan Ma
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Danial Hassani
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Bowen Peng
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Qifang Pan
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Yuhua Zhang
- Corporate R&D Division, Firmenich Aromatics (China) Co. Ltd., Shanghai, China
| | - Zhongxiang Deng
- Corporate R&D Division, Firmenich Aromatics (China) Co. Ltd., Shanghai, China
| | - Wenbo Liu
- Corporate R&D Division, Firmenich Aromatics (China) Co. Ltd., Shanghai, China
| | - Jixiu Zhang
- Corporate R&D Division, Firmenich Aromatics (China) Co. Ltd., Shanghai, China
| | - Lei Han
- Corporate R&D Division, Firmenich Aromatics (China) Co. Ltd., Shanghai, China
| | - Dongfang Chen
- Corporate R&D Division, Firmenich Aromatics (China) Co. Ltd., Shanghai, China
| | - Jingya Zhao
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Ling Li
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaofen Sun
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Kexuan Tang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-Shanghai Jiaotong University (SJTU)-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
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24
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Zhang C, Zhang B, Mu B, Zheng X, Zhao F, Lan W, Fu A, Luan S. A Thylakoid Membrane Protein Functions Synergistically with GUN5 in Chlorophyll Biosynthesis. PLANT COMMUNICATIONS 2020; 1:100094. [PMID: 33367259 PMCID: PMC7747962 DOI: 10.1016/j.xplc.2020.100094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/24/2020] [Accepted: 07/02/2020] [Indexed: 05/21/2023]
Abstract
Chlorophyll (Chl) is essential for photosynthetic reactions and chloroplast development. While the enzymatic pathway for Chl biosynthesis is well established, the regulatory mechanism underlying the homeostasis of Chl levels remains largely unknown. In this study, we identified CBD1 (Chlorophyll Biosynthetic Defect1), which functions in the regulation of chlorophyll biosynthesis. The CBD1 gene was expressed specifically in green tissues and its protein product was embedded in the thylakoid membrane. Furthermore, CBD1 was precisely co-expressed and functionally correlated with GUN5 (Genome Uncoupled 5). Analysis of chlorophyll metabolic intermediates indicated that cbd1 and cbd1gun5 mutants over-accumulated magnesium protoporphyrin IX (Mg-Proto IX). In addition, the cbd1 mutant thylakoid contained less Mg than the wild type not only as a result of lower Chl content, but also implicating CBD1 in Mg transport. This was supported by the finding that CBD1 complemented a Mg2+ uptake-deficient Salmonella strain under low Mg conditions. Taken together, these results indicate that CBD1 functions synergistically with CHLH/GUN5 in Mg-Proto IX processing, and may serve as a Mg-transport protein to maintain Mg homeostasis in the chloroplast.
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Affiliation(s)
- Chi Zhang
- The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an 710069, China
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Bin Zhang
- The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an 710069, China
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Baicong Mu
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
- Temasek Life Sciences Laboratory, Singapore 117604, Republic of Singapore
| | - Xiaojiang Zheng
- The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an 710069, China
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Fugeng Zhao
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Wenzhi Lan
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
- Corresponding author
| | - Aigen Fu
- The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an 710069, China
- Corresponding author
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
- Corresponding author
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25
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Chen JH, Chen ST, He NY, Wang QL, Zhao Y, Gao W, Guo FQ. Nuclear-encoded synthesis of the D1 subunit of photosystem II increases photosynthetic efficiency and crop yield. NATURE PLANTS 2020; 6:570-580. [PMID: 32313138 DOI: 10.1038/s41477-020-0629-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 02/27/2020] [Indexed: 05/08/2023]
Abstract
In photosynthetic organisms, the photosystem II (PSII) complex is the primary target of thermal damage. Plants have evolved a repair process to prevent the accumulation of damaged PSII. The repair of PSII largely involves de novo synthesis of proteins, particularly the D1 subunit protein encoded by the chloroplast gene psbA. Here we report that the allotropic expression of the psbA complementary DNA driven by a heat-responsive promoter in the nuclear genome sufficiently protects PSII from severe loss of D1 protein and dramatically enhances survival rates of the transgenic plants of Arabidopsis, tobacco and rice under heat stress. Unexpectedly, we found that the nuclear origin supplementation of the D1 protein significantly stimulates transgenic plant growth by enhancing net CO2 assimilation rates with increases in biomass and grain yield. These findings represent a breakthrough in bioengineering plants to achieve efficient photosynthesis and increase crop productivity under normal and heat-stress conditions.
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Affiliation(s)
- Juan-Hua Chen
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Si-Ting Chen
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Ning-Yu He
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Qing-Long Wang
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yao Zhao
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wei Gao
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fang-Qing Guo
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, Shanghai, China.
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26
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Chu CC, Swamy K, Li HM. Tissue-Specific Regulation of Plastid Protein Import via Transit-Peptide Motifs. THE PLANT CELL 2020; 32:1204-1217. [PMID: 32075863 PMCID: PMC7145487 DOI: 10.1105/tpc.19.00702] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/09/2020] [Accepted: 02/17/2020] [Indexed: 05/28/2023]
Abstract
Plastids differentiate into various functional types (chloroplasts, leucoplasts, chromoplasts, etc.) that have distinct proteomes depending on the specific tissue. Most plastid proteins are encoded by the nuclear genome, synthesized as higher molecular mass preproteins with an N-terminal transit peptide, and then posttranslationally imported from the cytosol. Evidence for tissue-specific regulation of import into plastids, and subsequent modulation of plastid proteomes, has been lacking. We quantified protein import into isolated pea (Pisum sativum) leaf chloroplasts and root leucoplasts and identified two transit-peptide motifs that specifically enhance preprotein import into root leucoplasts. Using a plastid preprotein expressed in both leaves and roots of stable transgenic plants, we showed that losing one of the leucoplast motifs interfered with its function in root leucoplasts but had no effect on its function in leaf chloroplasts. We assembled a list of all Arabidopsis (Arabid opsis thaliana) plastid preproteins encoded by recently duplicated genes and show that, within a duplicated preprotein pair, the isoform bearing the leucoplast motif usually has greater root protein abundance. Our findings represent a clear demonstration of tissue-specific regulation of organelle protein import and suggest that it operates by selective evolutionary retention of transit-peptide motifs, which enhances import into specific plastid types.
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Affiliation(s)
- Chiung-Chih Chu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Krishna Swamy
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Hsou-Min Li
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
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27
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Kumari K, Rai MP, Bansal N, Prashat GR, Kumari S, Srivathsa R, Dahuja A, Sachdev A, Praveen S, Vinutha T. Study of subcellular localization of Glycine max γ-tocopherol methyl transferase isoforms in N. benthamiana. 3 Biotech 2020; 10:110. [PMID: 32099748 DOI: 10.1007/s13205-020-2086-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/21/2020] [Indexed: 10/25/2022] Open
Abstract
Gamma-tocopherol methyltransferase (γ-TMT) converts γ-toc to α-toc-the rate limiting step in toc biosynthesis. Sequencing results revealed that the coding regions of γ-TMT1 and γ-TMT3 were strongly similar to each other (93% at amino acid level). Based on the differences in the N-terminal amino acids, Glycine max-γ-TMT proteins are categorized into three isoforms: γ-TMT1, 2 and 3. In silico structural analysis revealed the presence of chloroplast transit peptide (cTP) in γ-TMT1 and γ-TMT3 protein. However, other properties of transit peptide like presence of hydrophobic amino acids at the first three positions of N-terminal end and lower level of acidic amino acids were revealed only in γ-TMT3 protein. Subcellular localization of GFP fused γ-TMT1 and γ-TMT3 under 35S promoter was studied in Nicotiana benthamiana using confocal microscopy. Results showed that γ-TMT1 was found in the cytosol and γ-TMT3 was found to be localized both in cytosol and chloroplast. Further the presence γ-TMT3 in chloroplast was validated by quantifying α-tocopherol through UPLC. Thus the present study of cytosolic localization of the both γ-TMT1 and γ-TMT3 proteins and chloroplastic localization of γ-TMT3 will help to reveal the importance of γ-TMT encoded α-toc in protecting both chloroplastic and cell membrane from plant oxidative stress.
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28
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Protein import into chloroplasts via the Tic40-dependent and -independent pathways depends on the amino acid composition of the transit peptide. Biochem Biophys Res Commun 2019; 518:66-71. [PMID: 31400859 DOI: 10.1016/j.bbrc.2019.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/03/2019] [Indexed: 11/23/2022]
Abstract
Preprotein import into chloroplasts is mediated by the coordinated actions of translocons at the outer and inner envelopes of chloroplasts (Toc and Tic, respectively). The cleavable N-terminal transit peptide (TP) of preproteins plays an essential role in the import of preproteins into chloroplasts. The Tic40 protein, a component of the Tic complex, is believed to mediate the import of preproteins through the inner envelope. In this study, we aimed to obtain in vivo evidence supporting the role of Tic40 in preprotein import into chloroplasts. Contrary to previous findings, the import of various preproteins with wild-type TPs showed no difference between tic40 and wild-type protoplasts of Arabidopsis thaliana. However, the import of N-terminal mutants of the RbcS protein (RbcS-nt), in which basic amino acid residues (arginine and lysine) in the central region of the TP were substituted with neutral (alanine) or acidic (glutamic acid) amino acid residues, was dependent on Tic40. In addition, in tic40 protoplasts, the inner envelope protein Tic40 tagged with HA (hemagglutinin) showed more intermediate form present in the stroma. Based on these results, we propose that protein can be imported into chloroplast by either Tic40-independent or Tic40-dependent pathways depending on the types of TP.
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29
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Kim J, Na YJ, Park SJ, Baek SH, Kim DH. Biogenesis of chloroplast outer envelope membrane proteins. PLANT CELL REPORTS 2019; 38:783-792. [PMID: 30671649 DOI: 10.1007/s00299-019-02381-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/11/2019] [Indexed: 06/09/2023]
Abstract
Most organisms on Earth use glucose, a photosynthetic product, as energy source. The chloroplast, the home of photosynthesis, is the most representative and characteristic organelle in plants and is enclosed by the outer envelope and inner envelope membranes. The chloroplast biogenesis and unique functions are very closely associated with proteins in the two envelope membranes of the chloroplast. Especially, the chloroplast outer envelope membrane proteins have important roles in signal transduction, protein import, lipid biosynthesis and remodeling, exchange of ions and numerous metabolites, plastid division, movement, and host defense. Therefore, biogenesis of these membrane proteins of chloroplast outer envelope membrane is very important for biogenesis of the entire chloroplast proteome as well as plant development. Most proteins among the outer envelope membrane proteins are encoded by the nuclear genome and are post-translationally targeted to the chloroplast outer envelope membrane. In this process, cytoplasmic receptor and import machineries are required for efficient and correct targeting of these membrane proteins. In this review, we have summarized recent advances on the sorting, targeting, and insertion mechanisms of the outer envelope membrane proteins of chloroplasts and also provide future direction of the study on these topics.
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Affiliation(s)
- Jonghak Kim
- Department of Biology, Sunchon National University, Sunchon, 57922, South Korea
| | - Yun Jeong Na
- Department of Biology, Sunchon National University, Sunchon, 57922, South Korea
| | - Soon Ju Park
- Biological Sciences and Research Institute for Basic Science, Wonkwang University, Iksan, 54538, South Korea
| | - So-Hyeon Baek
- Department of Well-being Resources, Sunchon National University, Sunchon, 57922, South Korea
| | - Dae Heon Kim
- Department of Biology, Sunchon National University, Sunchon, 57922, South Korea.
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30
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Lee DW, Lee S, Lee J, Woo S, Razzak MA, Vitale A, Hwang I. Molecular Mechanism of the Specificity of Protein Import into Chloroplasts and Mitochondria in Plant Cells. MOLECULAR PLANT 2019; 12:951-966. [PMID: 30890495 DOI: 10.1016/j.molp.2019.03.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 02/19/2019] [Accepted: 03/10/2019] [Indexed: 05/04/2023]
Abstract
Plants possess both types of endosymbiotic organelles, chloroplasts and mitochondria. Transit peptides and presequences function as signal sequences for specific import into chloroplasts and mitochondria, respectively. However, how these highly similar signal sequences confer the protein import specificity remains elusive. Here, we show that mitochondrial- or chloroplast-specific import involves two distinct steps, specificity determination and translocation across envelopes, which are mediated by the N-terminal regions and functionally interchangeable C-terminal regions, respectively, of transit peptides and presequences. A domain harboring multiple-arginine and hydrophobic sequence motifs in the N-terminal regions of presequences was identified as the mitochondrial specificity factor. The presence of this domain and the absence of arginine residues in the N-terminal regions of otherwise common targeting signals confers specificity of protein import into mitochondria and chloroplasts, respectively. AtToc159, a chloroplast import receptor, also contributes to determining chloroplast import specificity. We propose that common ancestral sequences were functionalized into mitochondrial- and chloroplast-specific signal sequences by the presence and absence, respectively, of multiple-arginine and hydrophobic sequence motifs in the N-terminal region.
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Affiliation(s)
- Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Sumin Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Junho Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Seungjin Woo
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Md Abdur Razzak
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Alessandro Vitale
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale Delle Ricerche, Milano, Italy
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Korea; Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea.
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31
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Muthamilselvan T, Kim JS, Cheong G, Hwang I. Production of recombinant proteins through sequestration in chloroplasts: a strategy based on nuclear transformation and post-translational protein import. PLANT CELL REPORTS 2019; 38:825-833. [PMID: 31139894 DOI: 10.1007/s00299-019-02431-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/06/2019] [Accepted: 05/21/2019] [Indexed: 05/17/2023]
Abstract
Recently, plants have emerged as a lucrative alternative system for the production of recombinant proteins, as recombinant proteins produced in plants are safer and cheaper than those produced in bacteria and animal cell-based production systems. To obtain high yields in plants, recombinant proteins are produced in chloroplasts using different strategies. The first strategy is based on chloroplast transformation, followed by gene expression and translation in chloroplasts. This has proven to be a powerful approach for the production of proteins at high levels. The second approach is based on nuclear transformation, followed by post-translational import of proteins from the cytosol into chloroplasts. In the nuclear transformation approach, foreign genes are stably integrated into the nuclear genome or transiently expressed in the nucleus by non-integrating T-DNA. Although this approach also has great potential for protein production at high levels, it has not been thoroughly investigated. In this review, we focus on nuclear transformation-based protein expression and its subsequent sequestration in chloroplasts, and summarize the different strategies used for high-level production of recombinant proteins. We also discuss future directions for further improvements in protein production in chloroplasts through nuclear transformation-based gene expression.
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Affiliation(s)
- Thangarasu Muthamilselvan
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Jung Sun Kim
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, 54874, South Korea
| | - Gangwon Cheong
- Department of Life Science, Gyeongsang National University, Jinju, South Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea.
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32
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Xie X, Meesapyodsuk D, Qiu X. Enhancing oil production in Arabidopsis through expression of a ketoacyl-ACP synthase domain of the PUFA synthase from Thraustochytrium. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:172. [PMID: 31297160 PMCID: PMC6599236 DOI: 10.1186/s13068-019-1514-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 06/21/2019] [Indexed: 06/01/2023]
Abstract
BACKGROUND Plant seed oil is an important bioresource for human food and animal feed, as well as industrial bioproducts. Therefore, increasing oil content in seeds has been one of the primary targets in the breeding programs of oilseed crops. Thraustochytrium is a marine protist that can produce a high level of very long-chain polyunsaturated fatty acids (VLCPUFAs) using a PUFA synthase, a polyketide synthase-like fatty acid synthase with multiple catalytic domains. Our previous study showed that a KS domain from the synthase could complement an Escherichia coli mutant defective in β-ketoacyl-ACP synthase I (FabB) and increase the total fatty acid production. In this study, this KS domain from the PUFA synthase was further functionally analyzed in Arabidopsis thaliana for the capacity of oil production. RESULTS The plastidial expression of the KS domain could complement the defective phenotypes of a KASI knockout mutant generated by CRISPR/Cas9. Seed-specific expression of the domain in wild-type Arabidopsis significantly increased seed weight and seed oil, and altered the unsaturation level of fatty acids in seeds, as well as promoted seed germination and early seedling growth. CONCLUSIONS The condensation process of fatty acid biosynthesis in plants is a limiting step, and overexpression of the KS domain from a PUFA synthase of microbial origin offers a new strategy to increase oil production in oilseed plants.
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Affiliation(s)
- Xi Xie
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8 Canada
| | - Dauenpen Meesapyodsuk
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8 Canada
| | - Xiao Qiu
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8 Canada
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33
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Chen L, Wang X, Wang L, Fang Y, Pan X, Gao X, Zhang W. Functional characterization of chloroplast transit peptide in the small subunit of Rubisco in maize. JOURNAL OF PLANT PHYSIOLOGY 2019; 237:12-20. [PMID: 30999073 DOI: 10.1016/j.jplph.2019.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 06/09/2023]
Abstract
Functions of domains or motifs, which are encoded by the transit peptide (TP) of the precursor of the small subunit of Rubisco (prSSU), have been investigated intensively in dicots. Functional characterization of the prSSU TP, however, is still understudied in maize. In this study, we found that the TP of maize prSSU1 did not function fully in chloroplast targeting in Arabidopsis or vice versa, indicating the divergent function of TPs in chloroplast targeting between maize and Arabidopsis. Through deletion or substitution assays, we found that the N-terminal region of maize or Arabidopsis prSSU1 was necessary and sufficient for importing specifically the fused-green fluorescent protein (GFP) into each corresponding chloroplast. Finally, we found that the first-five amino acids and MM motif in the N-terminal domain of the maize TP played an essential role in maize chloroplast targeting. Thus, our analyses demonstrate that the N-terminal domain of the prSSU1 TP is the key determinant in chloroplast targeting between maize and Arabidopsis. Our study highlights the unique properties of the maize prSSU1 TP in chloroplast targeting, thus helping to understand the role of N-terminal domain in chloroplast targeting across species. It will help to manipulate chloroplast transit peptides (cTPs) for crop bioengineering.
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Affiliation(s)
- Lifen Chen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Ximeng Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Lei Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Yuan Fang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Xiucai Pan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Xiquan Gao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Wenli Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, China.
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Chen ZF, Kang XP, Nie HM, Zheng SW, Zhang TL, Zhou D, Xing GM, Sun S. Introduction of Exogenous Glycolate Catabolic Pathway Can Strongly Enhances Photosynthesis and Biomass Yield of Cucumber Grown in a Low-CO 2 Environment. FRONTIERS IN PLANT SCIENCE 2019; 10:702. [PMID: 31191593 PMCID: PMC6549358 DOI: 10.3389/fpls.2019.00702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/13/2019] [Indexed: 05/24/2023]
Abstract
Carbon dioxide (CO2) is very important for photosynthesis of green plants. CO2 concentration in the atmosphere is relatively stable, but it drops sharply after sunrise due to the tightness of the greenhouse and the absorption of CO2 by vegetable crops. Vegetables in greenhouses are chronically CO2 starved. To investigate the feasibility of using genetic engineering to improve the photosynthesis and yield of greenhouse cucumber in a low CO2 environment, five genes encoding glyoxylate carboligase (GCL), tartronic semialdehyde reductase (TSR), and glycolate dehydrogenase (GlcDH) in the glycolate catabolic pathway of Escherichia coli were partially or completely introduced into cucumber chloroplast. Both partial pathway by introducing GlcDH and full pathway expressing lines exhibited higher photosynthetic efficiency and biomass yield than wild-type (WT) controls in low CO2 environments. Expression of partial pathway by introducing GlcDH increased net photosynthesis by 14.9% and biomass yield by 44.9%, whereas the expression of the full pathway increased seed yield by 33.4% and biomass yield by 59.0%. Photosynthesis, fluorescence parameters, and enzymatic measurements confirmed that the introduction of glycolate catabolic pathway increased the activity of photosynthetic carbon assimilation-related enzymes and reduced the activity of photorespiration-related enzymes in cucumber, thereby promoting the operation of Calvin cycle and resulting in higher net photosynthetic rate even in low CO2 environments. This increase shows an improvement in the efficiency of the operation of the photosynthetic loop. However, the utilization of cucumber of low concentration CO2 was not alleviated. This study demonstrated the feasibility of introducing the pathway of exogenous glycolate catabolic pathway to improve the photosynthetic and bio-yield of cucumber in a low CO2 environment. These findings are of great significance for high photosynthetic efficiency breeding of greenhouse cucumber.
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Affiliation(s)
- Zhi-feng Chen
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
- Collaborative Innovation Center for improving the Quality and Efficiency of Greenhouse Vegetable in Shanxi Province, Taigu County, China
| | - Xiu-ping Kang
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
- Collaborative Innovation Center for improving the Quality and Efficiency of Greenhouse Vegetable in Shanxi Province, Taigu County, China
| | - Hong-mei Nie
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
- Collaborative Innovation Center for improving the Quality and Efficiency of Greenhouse Vegetable in Shanxi Province, Taigu County, China
| | - Shao-wen Zheng
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
- Collaborative Innovation Center for improving the Quality and Efficiency of Greenhouse Vegetable in Shanxi Province, Taigu County, China
| | - Tian-li Zhang
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
| | - Dan Zhou
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
| | - Guo-ming Xing
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
- Collaborative Innovation Center for improving the Quality and Efficiency of Greenhouse Vegetable in Shanxi Province, Taigu County, China
| | - Sheng Sun
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
- Collaborative Innovation Center for improving the Quality and Efficiency of Greenhouse Vegetable in Shanxi Province, Taigu County, China
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Pérez Di Giorgio JA, Lepage É, Tremblay-Belzile S, Truche S, Loubert-Hudon A, Brisson N. Transcription is a major driving force for plastid genome instability in Arabidopsis. PLoS One 2019; 14:e0214552. [PMID: 30943245 PMCID: PMC6447228 DOI: 10.1371/journal.pone.0214552] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/15/2019] [Indexed: 12/14/2022] Open
Abstract
Though it is an essential process, transcription can be a source of genomic instability. For instance, it may generate RNA:DNA hybrids as the nascent transcript hybridizes with the complementary DNA template. These hybrids, called R-loops, act as a major cause of replication fork stalling and DNA breaks. In this study, we show that lowering transcription and R-loop levels in plastids of Arabidopsis thaliana reduces DNA rearrangements and mitigates plastid genome instability phenotypes. This effect can be observed on a genome-wide scale, as the loss of the plastid sigma transcription factor SIG6 prevents DNA rearrangements by favoring conservative repair in the presence of ciprofloxacin-induced DNA damage or in the absence of plastid genome maintenance actors such as WHY1/WHY3, RECA1 and POLIB. Additionally, resolving R-loops by the expression of a plastid-targeted exogenous RNAse H1 produces similar results. We also show that highly-transcribed genes are more susceptible to DNA rearrangements, as increased transcription of the psbD operon by SIG5 correlates with more locus-specific rearrangements. The effect of transcription is not specific to Sigma factors, as decreased global transcription levels by mutation of heat-stress-induced factor HSP21, mutation of nuclear-encoded polymerase RPOTp, or treatment with transcription-inhibitor rifampicin all prevent the formation of plastid genome rearrangements, especially under induced DNA damage conditions.
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Affiliation(s)
| | - Étienne Lepage
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Samuel Tremblay-Belzile
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Sébastien Truche
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Audrey Loubert-Hudon
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Normand Brisson
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
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Shen BR, Wang LM, Lin XL, Yao Z, Xu HW, Zhu CH, Teng HY, Cui LL, Liu EE, Zhang JJ, He ZH, Peng XX. Engineering a New Chloroplastic Photorespiratory Bypass to Increase Photosynthetic Efficiency and Productivity in Rice. MOLECULAR PLANT 2019; 12:199-214. [PMID: 30639120 DOI: 10.1016/j.molp.2018.11.013] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 10/29/2018] [Accepted: 11/29/2018] [Indexed: 05/18/2023]
Abstract
Over the past few years, three photorespiratory bypasses have been introduced into plants, two of which led to observable increases in photosynthesis and biomass yield. However, most of the experiments were carried out using Arabidopsis under controlled environmental conditions, and the increases were only observed under low-light and short-day conditions. In this study, we designed a new photorespiratory bypass (called GOC bypass), characterized by no reducing equivalents being produced during a complete oxidation of glycolate into CO2 catalyzed by three rice-self-originating enzymes, i.e., glycolate oxidase, oxalate oxidase, and catalase. We successfully established this bypass in rice chloroplasts using a multi-gene assembly and transformation system. Transgenic rice plants carrying GOC bypass (GOC plants) showed significant increases in photosynthesis efficiency, biomass yield, and nitrogen content, as well as several other CO2-enriched phenotypes under both greenhouse and field conditions. Grain yield of GOC plants varied depending on seeding season and was increased significantly in the spring. We further demonstrated that GOC plants had significant advantages under high-light conditions and that the improvements in GOC plants resulted primarily from a photosynthetic CO2-concentrating effect rather than from improved energy balance. Taken together, our results reveal that engineering a newly designed chloroplastic photorespiratory bypass could increase photosynthetic efficiency and yield of rice plants grown in field conditions, particularly under high light.
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Affiliation(s)
- Bo-Ran Shen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Li-Min Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Xiu-Ling Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Zhen Yao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Hua-Wei Xu
- College of Agricultural, Henan University of Science and Technology, Luoyang, Henan, China
| | - Cheng-Hua Zhu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Hai-Yan Teng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Li-Li Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - E-E Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Jian-Jun Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Zheng-Hui He
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Xin-Xiang Peng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
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Kempinski C, Chappell J. Engineering triterpene metabolism in the oilseed of Arabidopsis thaliana. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:386-396. [PMID: 29979486 PMCID: PMC6335079 DOI: 10.1111/pbi.12984] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/21/2018] [Accepted: 06/27/2018] [Indexed: 05/13/2023]
Abstract
Squalene and botryococcene are linear, hydrocarbon triterpenes that have industrial and medicinal values. While natural sources for these compounds exist, there is a pressing need for robust, renewable production platforms. Oilseeds are an excellent target for heterologous production because of their roles as natural storage repositories and their capacity to produce precursors from photosynthetically-derived carbon. We generated transgenic Arabidopsis thaliana plants using a variety of engineering strategies (subcellular targeting and gene stacking) to assess the potential for oilseeds to produce these two compounds. Constructs used seed-specific promoters and evaluated expression of a triterpene synthase alone and in conjunction with a farnesyl diphosphate synthase (FPS) plus 1-deoxyxylulose 5-phosphate synthase (DXS). Constructs directing biosynthesis to the cytosol to harness isoprenoid precursors from the mevalonic acid (MVA) pathway were compared to those directing biosynthesis to the plastid compartment diverting precursors from the methylerythritol phosphate (MEP) pathway. On average, the highest accumulation for both compounds was achieved by targeting the triterpene synthase, FPS and DXS to the plastid (526.84 μg/g seed for botryococcene and 227.30 μg/g seed for squalene). Interestingly, a higher level accumulation of botryococcene (a non-native compound) was observed when the biosynthetic enzymes were targeted to the cytosol (>1000 μg/g seed in one line), but not squalene (natively produced in the cytosol). Not only do these results indicate the potential of engineering triterpene accumulation in oilseeds, but they also uncover some the unique regulatory mechanisms controlling triterpene metabolism in different cellular compartments of seeds.
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Affiliation(s)
- Chase Kempinski
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Joe Chappell
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
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38
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Yin JL, Wong WS. Production of santalenes and bergamotene in Nicotiana tabacum plants. PLoS One 2019; 14:e0203249. [PMID: 30608920 PMCID: PMC6319812 DOI: 10.1371/journal.pone.0203249] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 12/20/2018] [Indexed: 11/19/2022] Open
Abstract
Terpenes play an important role in plant-insect relationships, and these relationships can potentially be modified by altering the profile of terpenes emitted from plants using metabolic engineering methods. Transgenic plants generated by employing such methods offer the prospect of low-cost sustainable pest management; in this regard, we used chloroplast targeting and cytosolic mevalonic acid pathway enhancement in this study to investigate the interaction of santalenes and bergamotene with insects. The santalene- and bergamotene-emitting transgenic tobacco plants thus generated were utilized to study host preference in the green peach aphid (Myzus persicae (Sulzer)). The results showed that co-expression of either 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) or truncated HMGR with santalene synthase led to the production of higher amounts of santalenes and bergamotene in transgenic tobacco plants, and that these santalene- and bergamotene-emitting plants were attractive to green peach aphids. We accordingly propose that such transgenic plants may have potential application in pest management as a trap crop to prevent green peach aphid infestation of wild-type tobacco plants.
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Affiliation(s)
- Jun-Lin Yin
- YMU-HKBU Joint Laboratory of Traditional Natural Medicine, Yunnan Minzu University, Kunming, China
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore, Singapore
| | - Woon-Seng Wong
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore, Singapore
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39
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Richardson LGL, Small EL, Inoue H, Schnell DJ. Molecular Topology of the Transit Peptide during Chloroplast Protein Import. THE PLANT CELL 2018; 30:1789-1806. [PMID: 29991536 PMCID: PMC6139696 DOI: 10.1105/tpc.18.00172] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/26/2018] [Accepted: 07/06/2018] [Indexed: 05/04/2023]
Abstract
Chloroplast protein import is directed by the interaction of the targeting signal (transit peptide) of nucleus-encoded preproteins with translocons at the outer (TOC) and inner (TIC) chloroplast envelope membranes. Studies of the energetics and determinants of transit peptide binding have led to the hypothesis that import occurs through sequential recognition of transit peptides by components of TOC and TIC during protein import. To test this hypothesis, we employed a site-specific cross-linking approach to map transit peptide topology in relation to TOC-TIC components at specific stages of import in Arabidopsis thaliana and pea (Pisum sativum). We demonstrate that the transit peptide is in contact with Tic20 at the inner envelope in addition to TOC complex components at the earliest stages of chloroplast binding. Low levels of ATP hydrolysis catalyze the commitment of the preprotein to import by promoting further penetration across the envelope membranes and stabilizing the association of the preprotein with TOC-TIC. GTP hydrolysis at the TOC receptors serves as a checkpoint to regulate the ATP-dependent commitment of the preprotein to import and is not essential to drive preprotein import. Our results demonstrate the close cooperativity of the TOC and TIC machinery at each stage of transit peptide recognition and membrane translocation during protein import.
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Affiliation(s)
- Lynn G L Richardson
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Eliana L Small
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Hitoshi Inoue
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Danny J Schnell
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
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40
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Zhang B, Zhang C, Liu C, Jing Y, Wang Y, Jin L, Yang L, Fu A, Shi J, Zhao F, Lan W, Luan S. Inner Envelope CHLOROPLAST MANGANESE TRANSPORTER 1 Supports Manganese Homeostasis and Phototrophic Growth in Arabidopsis. MOLECULAR PLANT 2018; 11:943-954. [PMID: 29734003 DOI: 10.1016/j.molp.2018.04.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 05/18/2023]
Abstract
Manganese (Mn) is an essential catalytic metal in the Mn-cluster that oxidizes water to produce oxygen during photosynthesis. However, the transport protein(s) responsible for Mn2+ import into the chloroplast remains unknown. Here, we report the characterization of Arabidopsis CMT1 (Chloroplast Manganese Transporter 1), an evolutionarily conserved protein in the Uncharacterized Protein Family 0016 (UPF0016), that is required for manganese accumulation into the chloroplast. CMT1 is expressed primarily in green tissues, and its encoded product is localized in the inner envelope membrane of the chloroplast. Disruption of CMT1 in the T-DNA insertional mutant cmt1-1 resulted in stunted plant growth, defective thylakoid stacking, and severe reduction of photosystem II complexes and photosynthetic activity. Consistent with reduced oxygen evolution capacity, the mutant chloroplasts contained less manganese than the wild-type ones. In support of its function as a Mn transporter, CMT1 protein supported the growth and enabled Mn2+ accumulation in the yeast cells of Mn2+-uptake deficient mutant (Δsmf1). Taken together, our results indicate that CMT1 functions as an inner envelope Mn transporter responsible for chloroplast Mn2+ uptake.
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Affiliation(s)
- Bin Zhang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China; The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an, China
| | - Chi Zhang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China; The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an, China
| | - Congge Liu
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Yanping Jing
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Yuan Wang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Ling Jin
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Lei Yang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Aigen Fu
- The Key Laboratory of Western Resources Biology and Biological Technology, College of Life Sciences, Northwest University, Xi'an, China
| | - Jisen Shi
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, Key Laboratory of Forest Genetics and Biotechnology, Nanjing Forestry University, Nanjing 210037, China
| | - Fugeng Zhao
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Wenzhi Lan
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China.
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
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41
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Jiang Z, Kempinski C, Kumar S, Kinison S, Linscott K, Nybo E, Janze S, Wood C, Chappell J. Agronomic and chemical performance of field-grown tobacco engineered for triterpene and methylated triterpene metabolism. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:1110-1124. [PMID: 29069530 PMCID: PMC5978867 DOI: 10.1111/pbi.12855] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/08/2017] [Indexed: 05/13/2023]
Abstract
Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO2 levels) and triterpene content of select lines grown under field conditions were evaluated for three consecutive growing seasons. We observed that transgenic lines targeting enzymes to the chloroplasts accumulated 50-150 times more squalene than the lines targeting the enzymes to the cytoplasm, without compromising growth or photosynthesis. We also found that the transgenic lines directing botryococcene metabolism to the chloroplast accumulated 10- to 33-fold greater levels than the lines where the same enzymes were targeted to in the cytoplasm. However, growth of these high botryococcene accumulators was highly compromised, yet their photosynthesis rates remained unaffected. In addition, in the transgenic lines targeting a triterpene methyltransferase (TMT) to the chloroplasts of high squalene accumulators, 55%-65% of total squalene was methylated, whereas in the lines expressing a TMT in the cytoplasm, only 6%-13% of squalene was methylated. The growth of these methylated triterpene-accumulating lines was more compromised than that of nonmethylated squalene lines.
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Affiliation(s)
- Zuodong Jiang
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Chase Kempinski
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Santosh Kumar
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Scott Kinison
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Kristin Linscott
- Molecular and Cellular BiochemistryUniversity of KentuckyLexingtonKYUSA
| | - Eric Nybo
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Sarah Janze
- Department of StatisticsUniversity of KentuckyLexingtonKYUSA
| | - Connie Wood
- Department of StatisticsUniversity of KentuckyLexingtonKYUSA
| | - Joe Chappell
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
- Molecular and Cellular BiochemistryUniversity of KentuckyLexingtonKYUSA
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42
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Lee DW, Hwang I. Evolution and Design Principles of the Diverse Chloroplast Transit Peptides. Mol Cells 2018; 41:161-167. [PMID: 29487274 PMCID: PMC5881089 DOI: 10.14348/molcells.2018.0033] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 02/06/2018] [Indexed: 11/27/2022] Open
Abstract
Chloroplasts are present in organisms belonging to the kingdom Plantae. These organelles are thought to have originated from photosynthetic cyanobacteria through endosymbiosis. During endosymbiosis, most cyanobacterial genes were transferred to the host nucleus. Therefore, most chloroplast proteins became encoded in the nuclear genome and must return to the chloroplast after translation. The N-terminal cleavable transit peptide (TP) is necessary and sufficient for the import of nucleus-encoded interior chloroplast proteins. Over the past decade, extensive research on the TP has revealed many important characteristic features of TPs. These studies have also shed light on the question of how the many diverse TPs could have evolved to target specific proteins to the chloroplast. In this review, we summarize the characteristic features of TPs. We also highlight recent advances in our understanding of TP evolution and provide future perspectives about this important research area.
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Affiliation(s)
- Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673,
Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
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43
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Lee DW, Yoo YJ, Razzak MA, Hwang I. Prolines in Transit Peptides Are Crucial for Efficient Preprotein Translocation into Chloroplasts. PLANT PHYSIOLOGY 2018; 176:663-677. [PMID: 29158328 PMCID: PMC5761803 DOI: 10.1104/pp.17.01553] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/17/2017] [Indexed: 05/20/2023]
Abstract
Chloroplasts import many preproteins that can be classified based on their physicochemical properties. The cleavable N-terminal transit peptide (TP) of chloroplast preproteins contains all the information required for import into chloroplasts through Toc/Tic translocons. The question of whether and how the physicochemical properties of preproteins affect TP-mediated import into chloroplasts has not been elucidated. Here, we present evidence that Pro residues in TP mediate efficient translocation through the chloroplast envelope membranes for proteins containing transmembrane domains (TMDs) or proteins prone to aggregation. By contrast, the translocation of soluble proteins through the chloroplast envelope membranes is less dependent on TP prolines. Proless TPs failed to mediate protein translocation into chloroplasts; instead, these mutant TPs led to protein mistargeting to the chloroplast envelope membranes or nonspecific protein aggregation during import into chloroplasts. The mistargeting of TMD-containing proteins caused by Pro-less TPs in wild-type protoplasts was mimicked by wild-type TPs in hsp93-V protoplasts, in which preprotein translocation is compromised. We propose that the physicochemical properties of chloroplast proteins affect protein translocation through the chloroplast envelope, and prolines in TP have a crucial role in the efficient translocation of TMD-containing proteins.
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Affiliation(s)
- Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, and Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Yun-Joo Yoo
- Division of Integrative Biosciences and Biotechnology, and Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Md Abdur Razzak
- Division of Integrative Biosciences and Biotechnology, and Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, and Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Korea
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44
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Law YS, Ngan L, Yan J, Kwok LY, Sun Y, Cheng S, Schwenkert S, Lim BL. Multiple Kinases Can Phosphorylate the N-Terminal Sequences of Mitochondrial Proteins in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2018; 9:982. [PMID: 30042778 PMCID: PMC6048449 DOI: 10.3389/fpls.2018.00982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 06/18/2018] [Indexed: 05/06/2023]
Abstract
Phosphorylation of the transit peptides of nuclear-encoded preprotein is a well-known regulatory process of protein import in plant chloroplasts. In the Arabidopsis Protein Phosphorylation Site Database, 103 out of 802 mitochondrial proteins were found to contain one or more experimentally proven phosphorylation sites in their first 60 amino acid residues. Analysis of the N-terminal sequences of selected mitochondrial preproteins and their homologs from 64 plant species showed high conservation among phosphorylation sites. The ability of kinases from various sources including leaf extract (LE), root extract (RE), wheat germ lysate (WGL), and STY kinases to phosphorylate N-terminal sequences of several respiratory chain proteins were examined by in vitro kinase assays. The three STY kinases were shown to phosphorylate the N-terminal sequences of some proteins we tested but exhibited different specificities. Interestingly, the N-terminal sequences of two mitochondrial ATP synthase beta subunit 1/3 (pF1β-1/3) could be phosphorylated by LE and RE but not by STY kinases, suggesting that there are uncharacterized presequence-phosphorylating kinases other than STY kinases present in RE and LE. Mitochondrial import studies showed that the import of RRL-synthesized pF1βs was impeded by the treatment of LE, and the addition of a short SSU transit peptide containing a phosphorylatable 14-3-3 binding site could enhance the import of LE-treated pF1βs. Our results suggested that the transit peptide of pSSU can compete with the presequences of pF1βs for an uncharacterized kinase(s) in leaf. Altogether, our data showed that phosphorylation of transit peptides/presequences are not uncommon for chloroplast-targeted and mitochondria-targeted proteins, albeit possibly differentially regulated.
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Affiliation(s)
- Yee-Song Law
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Ling Ngan
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Junran Yan
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Lok Y. Kwok
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Yuzhe Sun
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Shifeng Cheng
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Serena Schwenkert
- Department of Biology I, Botany, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Boon L. Lim
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong
- *Correspondence: Boon L. Lim,
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Lee DW, Lee J, Hwang I. Sorting of nuclear-encoded chloroplast membrane proteins. CURRENT OPINION IN PLANT BIOLOGY 2017; 40:1-7. [PMID: 28668581 DOI: 10.1016/j.pbi.2017.06.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/07/2017] [Accepted: 06/14/2017] [Indexed: 05/11/2023]
Abstract
Among the many organelles in eukaryotic cells, chloroplasts have the most complex structure, with multiple suborganellar membranes, making protein targeting to chloroplasts, particularly to various suborganellar membranes, highly challenging. Multiple mechanisms function in the biogenesis of chloroplast membrane proteins. Nuclear-encoded nascent proteins can be targeted to the outer envelope membrane directly from the cytosol after translation, but their targeting to the inner envelope and thylakoid membranes requires multiple steps, including cytosolic sorting, translocation across the envelope membranes, sorting in the stroma, and insertion into their target membranes. In this review, we discuss the current knowledge about the sorting mechanisms of proteins to the two envelope membranes and the thylakoid membrane, along with perspectives for future research.
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Affiliation(s)
- Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Junho Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Republic of Korea; Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
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Razzak MA, Lee DW, Yoo YJ, Hwang I. Evolution of rubisco complex small subunit transit peptides from algae to plants. Sci Rep 2017; 7:9279. [PMID: 28839179 PMCID: PMC5571161 DOI: 10.1038/s41598-017-09473-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 07/26/2017] [Indexed: 11/09/2022] Open
Abstract
Chloroplasts evolved from a free-living cyanobacterium acquired by the ancestor of all photosynthetic eukaryotes, including algae and plants, through a single endosymbiotic event. During endosymbiotic conversion, the majority of genes in the endosymbiont were transferred to the host nucleus and many of the proteins encoded by these genes must therefore be transported into the chloroplast after translation in the cytosol. Chloroplast-targeted proteins contain a targeting signal, named the transit peptide (TP), at the N-terminus. However, the evolution of TPs is not well understood. In this study, TPs from RbcS (rubisco small subunit) were compared between lower and higher eukaryotes. Chlamydomonas reinhardtii RbcS (CrRbcS) TP was non-functional in Arabidopsis. However, inclusion of a critical sequence motif, FP-RK, from Arabidopsis thaliana RbcS (AtRbcS) TP allowed CrRbcS TP to deliver proteins into plant chloroplasts. The position of the FP-RK motif in CrRbcS TP was critical for function. The QMMVW sequence motif in CrRbcS TP was crucial for its transport activity in plants. CrRbcS TPs containing additional plant motifs remained functional in C. reinhardtii. These results suggest that TPs evolved by acquiring additional sequence motifs to support protein targeting to chloroplasts during evolution of land plants from algae.
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Affiliation(s)
- Md Abdur Razzak
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Yun-Joo Yoo
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea.
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An optimized transit peptide for effective targeting of diverse foreign proteins into chloroplasts in rice. Sci Rep 2017; 7:46231. [PMID: 28397859 PMCID: PMC5387683 DOI: 10.1038/srep46231] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/14/2017] [Indexed: 11/29/2022] Open
Abstract
Various chloroplast transit peptides (CTP) have been used to successfully target some foreign proteins into chloroplasts, but for other proteins these same CTPs have reduced localization efficiencies or fail completely. The underlying cause of the failures remains an open question, and more effective CTPs are needed. In this study, we initially observed that two E.coli enzymes, EcTSR and EcGCL, failed to be targeted into rice chloroplasts by the commonly-used rice rbcS transit peptide (rCTP) and were subsequently degraded. Further analyses revealed that the N-terminal unfolded region of cargo proteins is critical for their localization capability, and that a length of about 20 amino acids is required to attain the maximum localization efficiency. We considered that the unfolded region may alleviate the steric hindrance produced by the cargo protein, by functioning as a spacer to which cytosolic translocators can bind. Based on this inference, an optimized CTP, named RC2, was constructed. Analyses showed that RC2 can more effectively target diverse proteins, including EcTSR and EcGCL, into rice chloroplasts. Collectively, our results provide further insight into the mechanism of CTP-mediated chloroplastic localization, and more importantly, RC2 can be widely applied in future chloroplastic metabolic engineering, particularly for crop plants.
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Wimmer D, Bohnhorst P, Shekhar V, Hwang I, Offermann S. Transit peptide elements mediate selective protein targeting to two different types of chloroplasts in the single-cell C4 species Bienertia sinuspersici. Sci Rep 2017; 7:41187. [PMID: 28112241 PMCID: PMC5253730 DOI: 10.1038/srep41187] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/16/2016] [Indexed: 01/23/2023] Open
Abstract
Bienertia sinuspersici is a terrestrial plant that performs C4 photosynthesis within individual cells through operating a carbon concentrating mechanism between different subcellular domains including two types of chloroplasts. It is currently unknown how differentiation of two highly specialized chloroplasts within the same cell occurs as no similar cases have been reported. Here we show that this differentiation in photosynthetic cells of B. sinuspersici is enabled by a transit peptide (TP) mediated selective protein targeting mechanism. Mutations in the TPs cause loss of selectivity but not general loss of chloroplast import, indicating the mechanism operates by specifically blocking protein accumulation in one chloroplast type. Hybrid studies indicate that this selectivity is transferable to transit peptides of plants which perform C4 by cooperative function of chloroplasts between two photosynthetic cells. Codon swap experiments as well as introducing an artificial bait mRNA show that RNA affects are not crucial for the sorting process. In summary, our analysis shows how the mechanism of subcellular targeting to form two types of chloroplast within the same cell can be achieved. This information is not only crucial for understanding single-cell C4 photosynthesis; it provides new insights in control of subcellular protein targeting in cell biology.
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Affiliation(s)
- Diana Wimmer
- Institute for Botany, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| | - Philipp Bohnhorst
- Institute for Botany, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| | - Vinay Shekhar
- Faculty of Biology, Department Biology I – Botany, Ludwig-Maximilians-University Muenchen, Grosshaderner Strasse 2-4, 82152 Planegg-Martinsried, Germany
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790–784, Korea
| | - Sascha Offermann
- Institute for Botany, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover 30419, Germany
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Lee DW, Kim SJ, Oh YJ, Choi B, Lee J, Hwang I. Arabidopsis BAG1 Functions as a Cofactor in Hsc70-Mediated Proteasomal Degradation of Unimported Plastid Proteins. MOLECULAR PLANT 2016; 9:1428-1431. [PMID: 27343446 DOI: 10.1016/j.molp.2016.06.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/22/2016] [Accepted: 06/14/2016] [Indexed: 05/24/2023]
Affiliation(s)
- Dong Wook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Su Jin Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Young Jun Oh
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Bongsoo Choi
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Juhun Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea.
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