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Vadlamani G, Sukhoverkov KV, Haywood J, Breese KJ, Fisher MF, Stubbs KA, Bond CS, Mylne JS. Crystal structure of Arabidopsis thaliana HPPK/DHPS, a bifunctional enzyme and target of the herbicide asulam. PLANT COMMUNICATIONS 2022; 3:100322. [PMID: 35605193 PMCID: PMC9284294 DOI: 10.1016/j.xplc.2022.100322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/21/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Herbicides are vital for modern agriculture, but their utility is threatened by genetic or metabolic resistance in weeds, as well as regulatory barriers. Of the known herbicide modes of action, 7,8-dihydropterin synthase (DHPS), which is involved in folate biosynthesis, is targeted by just one commercial herbicide, asulam. A mimic of the substrate para-aminobenzoic acid, asulam is chemically similar to sulfonamide antibiotics, and although it is still in widespread use, asulam has faced regulatory scrutiny. With an entire mode of action represented by just one commercial agrochemical, we sought to improve the understanding of its plant target. Here we solve a 2.3 Å resolution crystal structure for Arabidopsis thaliana DHPS that is conjoined to 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), and we reveal a strong structural conservation with bacterial counterparts at the sulfonamide-binding pocket of DHPS. We demonstrate that asulam and the antibiotic sulfamethoxazole have herbicidal as well as antibacterial activity, and we explore the structural basis of their potency by modeling these compounds in mitochondrial HPPK/DHPS. Our findings suggest limited opportunity for the rational design of plant selectivity from asulam and indicate that pharmacokinetic or delivery differences between plants and microbes might be the best ways to safeguard this mode of action.
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Affiliation(s)
- Grishma Vadlamani
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Kirill V Sukhoverkov
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Joel Haywood
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Karen J Breese
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Mark F Fisher
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Keith A Stubbs
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Joshua S Mylne
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia.
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Lian T, Wang X, Li S, Jiang H, Zhang C, Wang H, Jiang L. Comparative Transcriptome Analysis Reveals Mechanisms of Folate Accumulation in Maize Grains. Int J Mol Sci 2022; 23:ijms23031708. [PMID: 35163628 PMCID: PMC8836222 DOI: 10.3390/ijms23031708] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 02/05/2023] Open
Abstract
Previously, the complexity of folate accumulation in the early stages of maize kernel development has been reported, but the mechanisms of folate accumulation are unclear. Two maize inbred lines, DAN3130 and JI63, with different patterns of folate accumulation and different total folate contents in mature kernels were used to investigate the transcriptional regulation of folate metabolism during late stages of kernel formation by comparative transcriptome analysis. The folate accumulation during DAP 24 to mature kernels could be controlled by circumjacent pathways of folate biosynthesis, such as pyruvate metabolism, glutamate metabolism, and serine/glycine metabolism. In addition, the folate variation between these two inbred lines was related to those genes among folate metabolism, such as genes in the pteridine branch, para-aminobenzoate branch, serine/tetrahydrofolate (THF)/5-methyltetrahydrofolate cycle, and the conversion of THF monoglutamate to THF polyglutamate. The findings provided insight into folate accumulation mechanisms during maize kernel formation to promote folate biofortification.
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Affiliation(s)
- Tong Lian
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (T.L.); (S.L.); (C.Z.)
- Plant Genetics, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
- Sanya Institute, Hainan Academy of Agricultural Sciences, Sanya 572000, China
| | - Xuxia Wang
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; (X.W.); (H.J.)
| | - Sha Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (T.L.); (S.L.); (C.Z.)
| | - Haiyang Jiang
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; (X.W.); (H.J.)
| | - Chunyi Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (T.L.); (S.L.); (C.Z.)
- Sanya Institute, Hainan Academy of Agricultural Sciences, Sanya 572000, China
| | - Huan Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (T.L.); (S.L.); (C.Z.)
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; (X.W.); (H.J.)
- National Agricultural Science and Technology Center, Chengdu 610213, China
- Correspondence: (H.W.); (L.J.)
| | - Ling Jiang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (T.L.); (S.L.); (C.Z.)
- Correspondence: (H.W.); (L.J.)
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Shohag MJI, Wei Y, Zhang J, Feng Y, Rychlik M, He Z, Yang X. Genetic and physiological regulation of folate in pak choi (Brassica rapa subsp. Chinensis) germplasm. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4914-4929. [PMID: 32639001 PMCID: PMC7410185 DOI: 10.1093/jxb/eraa218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 07/07/2020] [Indexed: 05/21/2023]
Abstract
Folates are one of the essential micronutrients for all living organisms. Due to inadequate dietary intake, folate deficiency remains prevalent in humans. Genetically diverse germplasms can potentially be used as parents in breeding programs and also for understanding the folate regulatory network. Therefore, we investigated the natural genetic diversity of folates and their physiological regulation in pak choi (Brassica rapa subsp. Chinensis) germplasm. The total folate concentration ranged from 52.7 μg 100 gFW-1 to 166.9 μg 100 gFW-1, with 3.2-fold variation. The main folate vitamer was represented by 5-CH3-H4folate, with 4.5-fold variation. The activities of GTP cyclohydrolase I and aminodeoxy chorismate synthase, the first step of folate synthesis, were high in high folate accessions and low in low folate accessions. Analysis of the transcription levels of 11 genes associated with folate metabolism demonstrated that the difference in folate concentrations may be primarily controlled at the post-transcriptional level. A general correlation between total folate and their precursors was observed. Folate diversity and chlorophyll content were tightly regulated through the methyl cycle. The diverse genetic variation in pak choi germplasm indicated the great genetic potential to integrate breeding programs for folate biofortification and unravel the physiological basis of folate homeostasis in planta.
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Affiliation(s)
- M J I Shohag
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, China
- Department of Agriculture, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, Bangladesh
- Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL, USA
| | - Yanyan Wei
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, China
- Cultivation Base of Guangxi Key Laboratory for Agro-Environment and Agro-Products Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Jie Zhang
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, China
- International Research Center for Environmental Membrane Biology, Department of Horticulture, Foshan University, Guangdong, China
| | - Ying Feng
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, China
| | - Michael Rychlik
- Chair of Analytical Food Chemistry, Technische Universitat Munchen, Lise-Meitner-Str. 34, Freising, Germany
| | - Zhenli He
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, China
- Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL, USA
| | - Xiaoe Yang
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, China
- Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL, USA
- Correspondence:
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Cheong MS, Seo KH, Chohra H, Yoon YE, Choe H, Kantharaj V, Lee YB. Influence of Sulfonamide Contamination Derived from Veterinary Antibiotics on Plant Growth and Development. Antibiotics (Basel) 2020; 9:antibiotics9080456. [PMID: 32731577 PMCID: PMC7460019 DOI: 10.3390/antibiotics9080456] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/25/2020] [Accepted: 07/27/2020] [Indexed: 11/16/2022] Open
Abstract
Veterinary antibiotics such as sulfonamides are widely used to increase feed efficiency and to protect against disease in livestock production. The sulfonamide antimicrobial mechanism involves the blocking of folate biosynthesis by inhibiting bacterial dihydropteroate synthase (DHPS) activity competitively. Interestingly, most treatment antibiotics can be released into the environment via manure and result in significant diffuse pollution in the environment. However, the physiological effects of sulfonamide during plant growth and development remain elusive because the plant response is dependent on folate biosynthesis and the concentration of antibiotics. Here, we present a chemical interaction docking model between Napa cabbage (Brassica campestris) DHPS and sulfamethoxazole and sulfamethazine, which are the most abundant sulfonamides detected in the environment. Furthermore, seedling growth inhibition was observed in lentil bean (Lens culinaris), rice (Oryza sativa), and Napa cabbage plants upon sulfonamide exposure. The results revealed that sulfonamide antibiotics target plant DHPS in a module similar to bacterial DHPS and affect early growth and the development of crop seedlings. Taking these results together, we suggest that sulfonamides act as pollutants in crop fields.
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Affiliation(s)
- Mi Sun Cheong
- Division of Applied Life Science (BK 21 Plus Program), Gyeongsang National University, Jinju 52828, Korea; (M.S.C.); (H.C.); (Y.E.Y.); (H.C.); (V.K.)
- Institute of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju 52828, Korea
| | - Kyung Hye Seo
- Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, RDA, Eumsung 27709, Korea;
| | - Hadjer Chohra
- Division of Applied Life Science (BK 21 Plus Program), Gyeongsang National University, Jinju 52828, Korea; (M.S.C.); (H.C.); (Y.E.Y.); (H.C.); (V.K.)
| | - Young Eun Yoon
- Division of Applied Life Science (BK 21 Plus Program), Gyeongsang National University, Jinju 52828, Korea; (M.S.C.); (H.C.); (Y.E.Y.); (H.C.); (V.K.)
| | - Hyeonji Choe
- Division of Applied Life Science (BK 21 Plus Program), Gyeongsang National University, Jinju 52828, Korea; (M.S.C.); (H.C.); (Y.E.Y.); (H.C.); (V.K.)
| | - Vimalraj Kantharaj
- Division of Applied Life Science (BK 21 Plus Program), Gyeongsang National University, Jinju 52828, Korea; (M.S.C.); (H.C.); (Y.E.Y.); (H.C.); (V.K.)
| | - Yong Bok Lee
- Division of Applied Life Science (BK 21 Plus Program), Gyeongsang National University, Jinju 52828, Korea; (M.S.C.); (H.C.); (Y.E.Y.); (H.C.); (V.K.)
- Institute of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju 52828, Korea
- Correspondence: ; Tel.: +82-557-721-967
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Gorelova V, Bastien O, De Clerck O, Lespinats S, Rébeillé F, Van Der Straeten D. Evolution of folate biosynthesis and metabolism across algae and land plant lineages. Sci Rep 2019; 9:5731. [PMID: 30952916 PMCID: PMC6451014 DOI: 10.1038/s41598-019-42146-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 03/25/2019] [Indexed: 11/09/2022] Open
Abstract
Tetrahydrofolate and its derivatives, commonly known as folates, are essential for almost all living organisms. Besides acting as one-carbon donors and acceptors in reactions producing various important biomolecules such as nucleic and amino acids, as well as pantothenate, they also supply one-carbon units for methylation reactions. Plants along with bacteria, yeast and fungi synthesize folates de novo and therefore constitute a very important dietary source of folates for animals. All the major steps of folate biosynthesis and metabolism have been identified but only few have been genetically characterized in a handful of model plant species. The possible differences in the folate pathway between various plant and algal species have never been explored. In this study we present a comprehensive comparative study of folate biosynthesis and metabolism of all major land plant lineages as well as green and red algae. The study identifies new features of plant folate metabolism that might open new directions to folate research in plants.
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Affiliation(s)
- V Gorelova
- Department of Biology, Laboratory of Functional Plant Biology, Ghent University, K.L Ledeganckstraat 35, 9000, Ghent, Belgium.,Department of Botany and Plant Biology, Laboratory of Plant Biochemistry and Physiology, University of Geneva, Quai E. Ansermet 30, 1211, Geneva, Switzerland
| | - O Bastien
- Laboratoire de Physiologie Cellulaire Vegetale, UMR168 CNRS-CEA-INRA-Universite Joseph Fourier Grenoble I, Bioscience and Biotechnologies Institute of Grenoble, CEA-Grenoble, 17 rue des Martyrs, 38054, Grenoble, Cedex 9, France
| | - O De Clerck
- Department of Biology, Phycology Research Group, Ghent University, Krijgslaan 281, 9000, Gent, Belgium
| | - S Lespinats
- Laboratoire de Physiologie Cellulaire Vegetale, UMR168 CNRS-CEA-INRA-Universite Joseph Fourier Grenoble I, Bioscience and Biotechnologies Institute of Grenoble, CEA-Grenoble, 17 rue des Martyrs, 38054, Grenoble, Cedex 9, France
| | - F Rébeillé
- Laboratoire de Physiologie Cellulaire Vegetale, UMR168 CNRS-CEA-INRA-Universite Joseph Fourier Grenoble I, Bioscience and Biotechnologies Institute of Grenoble, CEA-Grenoble, 17 rue des Martyrs, 38054, Grenoble, Cedex 9, France
| | - D Van Der Straeten
- Department of Biology, Laboratory of Functional Plant Biology, Ghent University, K.L Ledeganckstraat 35, 9000, Ghent, Belgium.
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Gorelova V, Ambach L, Rébeillé F, Stove C, Van Der Straeten D. Folates in Plants: Research Advances and Progress in Crop Biofortification. Front Chem 2017; 5:21. [PMID: 28424769 PMCID: PMC5372827 DOI: 10.3389/fchem.2017.00021] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/09/2017] [Indexed: 11/13/2022] Open
Abstract
Folates, also known as B9 vitamins, serve as donors and acceptors in one-carbon (C1) transfer reactions. The latter are involved in synthesis of many important biomolecules, such as amino acids, nucleic acids and vitamin B5. Folates also play a central role in the methyl cycle that provides one-carbon groups for methylation reactions. The important functions fulfilled by folates make them essential in all living organisms. Plants, being able to synthesize folates de novo, serve as an excellent dietary source of folates for animals that lack the respective biosynthetic pathway. Unfortunately, the most important staple crops such as rice, potato and maize are rather poor sources of folates. Insufficient folate consumption is known to cause severe developmental disorders in humans. Two approaches are employed to fight folate deficiency: pharmacological supplementation in the form of folate pills and biofortification of staple crops. As the former approach is considered rather costly for the major part of the world population, biofortification of staple crops is viewed as a decent alternative in the struggle against folate deficiency. Therefore, strategies, challenges and recent progress of folate enhancement in plants will be addressed in this review. Apart from the ever-growing need for the enhancement of nutritional quality of crops, the world population faces climate change catastrophes or environmental stresses, such as elevated temperatures, drought, salinity that severely affect growth and productivity of crops. Due to immense diversity of their biochemical functions, folates take part in virtually every aspect of plant physiology. Any disturbance to the plant folate metabolism leads to severe growth inhibition and, as a consequence, to a lower productivity. Whereas today's knowledge of folate biochemistry can be considered very profound, evidence on the physiological roles of folates in plants only starts to emerge. In the current review we will discuss the implication of folates in various aspects of plant physiology and development.
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Affiliation(s)
- Vera Gorelova
- Laboratory of Functional Plant Biology, Department of Biology, Ghent UniversityGhent, Belgium
| | - Lars Ambach
- Laboratory of Toxicology, Department of Bioanalysis, Ghent UniversityGhent, Belgium
| | - Fabrice Rébeillé
- Laboratoire de Physiologie Cellulaire Végétale, Bioscience and Biotechnologies Institute of Grenoble, CEA-GrenobleGrenoble, France
| | - Christophe Stove
- Laboratory of Toxicology, Department of Bioanalysis, Ghent UniversityGhent, Belgium
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Thiaville JJ, Frelin O, García-Salinas C, Harrison K, Hasnain G, Horenstein NA, Díaz de la Garza RI, Henry CS, Hanson AD, de Crécy-Lagard V. Experimental and Metabolic Modeling Evidence for a Folate-Cleaving Side-Activity of Ketopantoate Hydroxymethyltransferase (PanB). Front Microbiol 2016; 7:431. [PMID: 27065985 PMCID: PMC4814558 DOI: 10.3389/fmicb.2016.00431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 03/17/2016] [Indexed: 01/07/2023] Open
Abstract
Tetrahydrofolate (THF) and its one-carbon derivatives, collectively termed folates, are essential cofactors, but are inherently unstable. While it is clear that chemical oxidation can cleave folates or damage their pterin precursors, very little is known about enzymatic damage to these molecules or about whether the folate biosynthesis pathway responds adaptively to damage to its end-products. The presence of a duplication of the gene encoding the folate biosynthesis enzyme 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (FolK) in many sequenced bacterial genomes combined with a strong chromosomal clustering of the folK gene with panB, encoding the 5,10-methylene-THF-dependent enzyme ketopantoate hydroxymethyltransferase, led us to infer that PanB has a side activity that cleaves 5,10-methylene-THF, yielding a pterin product that is recycled by FolK. Genetic and metabolic analyses of Escherichia coli strains showed that overexpression of PanB leads to accumulation of the likely folate cleavage product 6-hydroxymethylpterin and other pterins in cells and medium, and—unexpectedly—to a 46% increase in total folate content. In silico modeling of the folate biosynthesis pathway showed that these observations are consistent with the in vivo cleavage of 5,10-methylene-THF by a side-activity of PanB, with FolK-mediated recycling of the pterin cleavage product, and with regulation of folate biosynthesis by folates or their damage products.
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Affiliation(s)
- Jennifer J Thiaville
- Department of Microbiology and Cell Science, University of Florida Gainesville, FL, USA
| | - Océane Frelin
- Horticultural Sciences Department, University of Florida Gainesville, FL, USA
| | | | - Katherine Harrison
- Department of Microbiology and Cell Science, University of Florida Gainesville, FL, USA
| | - Ghulam Hasnain
- Horticultural Sciences Department, University of Florida Gainesville, FL, USA
| | | | | | - Christopher S Henry
- Mathematics and Computer Science Division, Argonne National LaboratoryArgonne, IL, USA; Computation Institute, The University of ChicagoChicago, IL, USA
| | - Andrew D Hanson
- Horticultural Sciences Department, University of Florida Gainesville, FL, USA
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of FloridaGainesville, FL, USA; Genetics Institute, University of FloridaGainesville, FL, USA
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Dong W, Cheng ZJ, Lei CL, Wang XL, Wang JL, Wang J, Wu FQ, Zhang X, Guo XP, Zhai HQ, Wan JM. Overexpression of folate biosynthesis genes in rice (Oryza sativa L.) and evaluation of their impact on seed folate content. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2014; 69:379-85. [PMID: 25432789 DOI: 10.1007/s11130-014-0450-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Folate (vitamin B9) deficiency is a global health problem especially in developing countries where the major staple foods such as rice contain extremely low folates. Biofortification of rice could be an alternative complement way to fight folate deficiency. In this study, we evaluated the availability of the genes in each step of folate biosynthesis pathway for rice folate enhancement in the japonica variety kitaake genetic background. The first enzymes GTP cyclohydrolase I (GTPCHI) and aminodeoxychorismate synthase (ADCS) in the pterin and para-aminobenzoate branches resulted in significant increase in seed folate content, respectively (P < 0.01). Overexpression of two closely related enzymes dihydrofolate synthase (DHFS) and folypolyglutamate synthase (FPGS), which perform the first and further additions of glutamates, produced slightly increase in seed folate content separately. The GTPCHI transgene was combined with each of the other transgenes except ADCS to investigate the effects of gene stacking on seed folate accumulation. Seed folate contents in the gene-stacked plants were higher than the individual low-folate transgenic parents, but lower than the high-folate GTPCHI transgenic lines, pointing to an inadequate supply of para-aminobenzoic acid (PABA) precursor initiated by ADCS in constraining folate overproduction in gene-stacked plants.
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Affiliation(s)
- Wei Dong
- National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
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9
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Araújo WL, Nunes-Nesi A, Nikoloski Z, Sweetlove LJ, Fernie AR. Metabolic control and regulation of the tricarboxylic acid cycle in photosynthetic and heterotrophic plant tissues. PLANT, CELL & ENVIRONMENT 2012; 35:1-21. [PMID: 21477125 DOI: 10.1111/j.1365-3040.2011.02332.x] [Citation(s) in RCA: 191] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The tricarboxylic acid (TCA) cycle is a crucial component of respiratory metabolism in both photosynthetic and heterotrophic plant organs. All of the major genes of the tomato TCA cycle have been cloned recently, allowing the generation of a suite of transgenic plants in which the majority of the enzymes in the pathway are progressively decreased. Investigations of these plants have provided an almost complete view of the distribution of control in this important pathway. Our studies suggest that citrate synthase, aconitase, isocitrate dehydrogenase, succinyl CoA ligase, succinate dehydrogenase, fumarase and malate dehydrogenase have control coefficients flux for respiration of -0.4, 0.964, -0.123, 0.0008, 0.289, 0.601 and 1.76, respectively; while 2-oxoglutarate dehydrogenase is estimated to have a control coefficient of 0.786 in potato tubers. These results thus indicate that the control of this pathway is distributed among malate dehydrogenase, aconitase, fumarase, succinate dehydrogenase and 2-oxoglutarate dehydrogenase. The unusual distribution of control estimated here is consistent with specific non-cyclic flux mode and cytosolic bypasses that operate in illuminated leaves. These observations are discussed in the context of known regulatory properties of the enzymes and some illustrative examples of how the pathway responds to environmental change are given.
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Affiliation(s)
- Wagner L Araújo
- Max-Planck Institute for Molecular Plant Physiology, Am Mühlenberg 1, Germany
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Hanson AD, Gregory JF. Folate biosynthesis, turnover, and transport in plants. ANNUAL REVIEW OF PLANT BIOLOGY 2011; 62:105-25. [PMID: 21275646 DOI: 10.1146/annurev-arplant-042110-103819] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Folates are essential cofactors for one-carbon transfer reactions and are needed in the diets of humans and animals. Because plants are major sources of dietary folate, plant folate biochemistry has long been of interest but progressed slowly until the genome era. Since then, genome-enabled approaches have brought rapid advances: We now know (a) all the plant folate synthesis genes and some genes of folate turnover and transport, (b) certain mechanisms governing folate synthesis, and (c) the subcellular locations of folate synthesis enzymes and of folates themselves. Some of this knowledge has been applied, simply and successfully, to engineer folate-enriched food crops (i.e., biofortification). Much remains to be discovered about folates, however, particularly in relation to homeostasis, catabolism, membrane transport, and vacuolar storage. Understanding these processes, which will require both biochemical and -omics research, should lead to improved biofortification strategies based on transgenic or conventional approaches.
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Affiliation(s)
- Andrew D Hanson
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32611, USA
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11
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Pemble CW, Mehta PK, Mehra S, Li Z, Nourse A, Lee RE, White SW. Crystal structure of the 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase•dihydropteroate synthase bifunctional enzyme from Francisella tularensis. PLoS One 2010; 5:e14165. [PMID: 21152407 PMCID: PMC2994781 DOI: 10.1371/journal.pone.0014165] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 11/09/2010] [Indexed: 11/30/2022] Open
Abstract
The 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) and dihydropteroate synthase (DHPS) enzymes catalyze sequential metabolic reactions in the folate biosynthetic pathway of bacteria and lower eukaryotes. Both enzymes represent validated targets for the development of novel anti-microbial therapies. We report herein that the genes which encode FtHPPK and FtDHPS from the biowarfare agent Francisella tularensis are fused into a single polypeptide. The potential of simultaneously targeting both modules with pterin binding inhibitors prompted us to characterize the molecular details of the multifunctional complex. Our high resolution crystallographic analyses reveal the structural organization between FtHPPK and FtDHPS which are tethered together by a short linker. Additional structural analyses of substrate complexes reveal that the active sites of each module are virtually indistinguishable from those of the monofunctional enzymes. The fused bifunctional enzyme therefore represents an excellent vehicle for finding inhibitors that engage the pterin binding pockets of both modules that have entirely different architectures. To demonstrate that this approach has the potential of producing novel two-hit inhibitors of the folate pathway, we identify and structurally characterize a fragment-like molecule that simultaneously engages both active sites. Our study provides a molecular framework to study the enzyme mechanisms of HPPK and DHPS, and to design novel and much needed therapeutic compounds to treat infectious diseases.
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Affiliation(s)
- Charles W. Pemble
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Perdeep K. Mehta
- Department of Information Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Smriti Mehra
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Zhenmei Li
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Amanda Nourse
- The Hartwell Center, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Richard E. Lee
- Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
- * E-mail: (SWW); (REL)
| | - Stephen W. White
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
- * E-mail: (SWW); (REL)
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12
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Probing the roles of non-homologous insertions in the N-terminal domain of Plasmodium falciparum hydroxymethylpterin pyrophosphokinase–dihydropteroate synthase. Mol Biochem Parasitol 2009; 168:135-42. [DOI: 10.1016/j.molbiopara.2009.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 06/29/2009] [Accepted: 07/09/2009] [Indexed: 11/19/2022]
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13
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Van Wilder V, De Brouwer V, Loizeau K, Gambonnet B, Albrieux C, Van Der Straeten D, Lambert WE, Douce R, Block MA, Rebeille F, Ravanel S. C1 metabolism and chlorophyll synthesis: the Mg-protoporphyrin IX methyltransferase activity is dependent on the folate status. THE NEW PHYTOLOGIST 2008; 182:137-145. [PMID: 19076298 DOI: 10.1111/j.1469-8137.2008.02707.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
* Tetrahydrofolate derivatives are central cofactors of C1 metabolism. Using methotrexate as a specific inhibitor of folate biosynthesis, we altered the folate status in 10-d-old etiolated pea (Pisum sativum) leaves and followed the rate of chlorophyll synthesis upon illumination. * In our conditions, the folate concentration decreased only from 5.7 to 4.2 nmol g(-1) FW, but the amount of chlorophyll after 24 h of illumination was reduced 2.5 times. Folate status and rate of chlorophyll synthesis were apparently correlated through the methyl cycle. * Indeed, we observed that methyl-tetrahydrofolate was the folate derivative most affected by the treatment; the decrease of methyl-tetrahydrofolate was associated with a sharp rise in homocysteine and S-adenosylhomocysteine concentrations, which are normally maintained at very low values, shifting the methylation index (S-adenosylmethionine/S-adenosylhomocysteine ratio) from 7 to 1; the decrease of the methylation index reduced by a factor of 3 the activity of the Mg-protoporphyrin IX methyltransferase (CHLM), an essential enzyme for chlorophyll synthesis. CHLM gene expression and protein concentration remained unchanged, suggesting that this inhibition relied essentially on metabolic regulation. * These results point out that an even moderate change in the folate status may affect plant development and adaptation.
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Affiliation(s)
- Valérie Van Wilder
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Veerle De Brouwer
- Laboratory of Toxicology, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium
| | - Karen Loizeau
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Bernadette Gambonnet
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Catherine Albrieux
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Dominique Van Der Straeten
- Unit Plant Hormone Signaling and Bioimaging, Department of Molecular Genetics, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium
| | - Willy E Lambert
- Laboratory of Toxicology, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium
| | - Roland Douce
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Maryse A Block
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Fabrice Rebeille
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Stéphane Ravanel
- Laboratoire de Physiologie Cellulaire Végétale, UMR5168 CNRS-CEA-INRA-Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
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14
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Rébeillé F, Alban C, Bourguignon J, Ravanel S, Douce R. The role of plant mitochondria in the biosynthesis of coenzymes. PHOTOSYNTHESIS RESEARCH 2007; 92:149-62. [PMID: 17464574 DOI: 10.1007/s11120-007-9167-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 04/05/2007] [Indexed: 05/15/2023]
Abstract
This last decade, many efforts were undertaken to understand how coenzymes, including vitamins, are synthesized in plants. Surprisingly, these metabolic pathways were often "quartered" between different compartments of the plant cell. Among these compartments, mitochondria often appear to have a key role, catalyzing one or several steps in these pathways. In the present review we will illustrate these new and important biosynthetic functions found in plant mitochondria by describing the most recent findings about the synthesis of two vitamins (folate and biotin) and one non-vitamin coenzyme (lipoate). The complexity of these metabolic routes raise intriguing questions, such as how the intermediate metabolites and the end-product coenzymes are exchanged between the various cellular territories, or what are the physiological reasons, if any, for such compartmentalization.
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Affiliation(s)
- Fabrice Rébeillé
- Institut de Recherches en Technologies et Sciences pour le Vivant, UMR5168 CEA/CNRS/INRA/Université Joseph Fourier Grenoble, CEA-Grenoble, 17 rue des Martyrs, Grenoble Cedex 9, 38054, France,
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15
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Díaz de la Garza RI, Gregory JF, Hanson AD. Folate biofortification of tomato fruit. Proc Natl Acad Sci U S A 2007; 104:4218-22. [PMID: 17360503 PMCID: PMC1810332 DOI: 10.1073/pnas.0700409104] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Folate deficiency leads to neural tube defects and other human diseases, and is a global health problem. Because plants are major folate sources for humans, we have sought to enhance plant folate levels (biofortification). Folates are synthesized from pteridine, p-aminobenzoate (PABA), and glutamate precursors. Previously, we increased pteridine production in tomato fruit up to 140-fold by overexpressing GTP cyclohydrolase I, the first enzyme of pteridine synthesis. This strategy increased folate levels 2-fold, but engineered fruit were PABA-depleted. We report here the engineering of fruit-specific overexpression of aminodeoxychorismate synthase, which catalyzes the first step of PABA synthesis. The resulting fruit contained an average of 19-fold more PABA than controls. When transgenic PABA- and pteridine-overproduction traits were combined by crossing, vine-ripened fruit accumulated up to 25-fold more folate than controls. Folate accumulation was almost as high (up to 15-fold) in fruit harvested green and ripened by ethylene-gassing, as occurs in commerce. The accumulated folates showed normal proportions of one-carbon forms, with 5-methyltetrahydrofolate the most abundant, but were less extensively polyglutamylated than controls. Folate concentrations in developing fruit did not change in controls, but increased continuously throughout ripening in transgenic fruit. Pteridine and PABA levels in transgenic fruit were >20-fold higher than in controls, but the pathway intermediates dihydropteroate and dihydrofolate did not accumulate, pointing to a flux constraint at the dihydropteroate synthesis step. The folate levels we achieved provide the complete adult daily requirement in less than one standard serving.
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Affiliation(s)
| | - Jesse F. Gregory
- Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611
| | - Andrew D. Hanson
- Departments of *Horticultural Sciences and
- To whom correspondence should be addressed. E-mail:
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16
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Rébeillé F, Jabrin S, Bligny R, Loizeau K, Gambonnet B, Van Wilder V, Douce R, Ravanel S. Methionine catabolism in Arabidopsis cells is initiated by a gamma-cleavage process and leads to S-methylcysteine and isoleucine syntheses. Proc Natl Acad Sci U S A 2006; 103:15687-92. [PMID: 17030798 PMCID: PMC1622882 DOI: 10.1073/pnas.0606195103] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite recent progress in elucidating the regulation of methionine (Met) synthesis, little is known about the catabolism of this amino acid in plants. In this article, we present several lines of evidence indicating that the cleavage of Met catalyzed by Met gamma-lyase is the first step in this process. First, we cloned an Arabidopsis cDNA coding a functional Met gamma-lyase (AtMGL), a cytosolic enzyme catalyzing the conversion of Met into methanethiol, alpha-ketobutyrate, and ammonia. AtMGL is present in all of the Arabidopsis organs and tissues analyzed, except in quiescent dry mature seeds, thus suggesting that AtMGL is involved in the regulation of Met homeostasis in various situations. Also, we demonstrated that the expression of AtMGL was induced in Arabidopsis cells in response to high Met levels, probably to bypass the elevated Km of the enzyme for Met. Second, [13C]-NMR profiling of Arabidopsis cells fed with [13C]Met allowed us to identify labeled S-adenosylmethionine, S-methylmethionine, S-methylcysteine (SMC), and isoleucine (Ile). The unexpected production of SMC and Ile was directly associated to the function of Met gamma-lyase. Indeed, we showed that part of the methanethiol produced during Met cleavage could react with an activated form of serine to produce SMC. The second product of Met cleavage, alpha-ketobutyrate, entered the pathway of Ile synthesis in plastids. Together, these data indicate that Met catabolism in Arabidopsis cells is initiated by a gamma-cleavage process and can result in the formation of the essential amino acid Ile and a potential storage form for sulfide or methyl groups, SMC.
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Affiliation(s)
- Fabrice Rébeillé
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Samuel Jabrin
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Richard Bligny
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Karen Loizeau
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Bernadette Gambonnet
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Valérie Van Wilder
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
| | - Roland Douce
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique–Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, Commissariat à l'Energie Atomique, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9, France
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Orsomando G, Bozzo GG, de la Garza RD, Basset GJ, Quinlivan EP, Naponelli V, Rébeillé F, Ravanel S, Gregory JF, Hanson AD. Evidence for folate-salvage reactions in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 46:426-35. [PMID: 16623903 DOI: 10.1111/j.1365-313x.2006.02685.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Folates in vivo undergo oxidative cleavage, giving pterin and p-aminobenzoylglutamate (pABAGlu) moieties. These breakdown products are excreted in animals, but their fate is unclear in microorganisms and unknown in plants. As indirect evidence from this and previous studies strongly suggests that plants can have high folate-breakdown rates (approximately 10% per day), salvage of the cleavage products seems likely. Four sets of observations support this possibility. First, cleavage products do not normally accumulate: pools of pABAGlu (including its polyglutamyl forms) are equivalent to, at most, 4-14% of typical total folate pools in Arabidopsis thaliana, Lycopersicon esculentum and Pisum sativum tissues. Pools of the pterin oxidation end-product pterin-6-carboxylate are, likewise, fairly small (3-37%) relative to total folate pools. Second, little pABAGlu built up in A. thaliana plantlets when net folate breakdown was induced by blocking folate synthesis with sulfanilamide. Third, A. thaliana and L. esculentum tissues readily converted supplied breakdown products to folate synthesis precursors: pABAGlu was hydrolysed to p-aminobenzoate and glutamate, and dihydropterin-6-aldehyde was reduced to 6-hydroxymethyldihydropterin. Fourth, both these reactions were detected in vitro; the reduction used NADPH as cofactor. An alternative salvage route for pABAGlu, direct reincorporation into dihydrofolate via the action of dihydropteroate synthase, appears implausible from the properties of this enzyme. We conclude that plants are excellent organisms in which to explore the biochemistry of folate salvage.
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Affiliation(s)
- Giuseppe Orsomando
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
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18
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Berglez J, Pilling P, Macreadie I, Fernley RT. Purification, properties, and crystallization of Saccharomyces cerevisiae dihydropterin pyrophosphokinase-dihydropteroate synthase. Protein Expr Purif 2005; 41:355-62. [PMID: 15866722 DOI: 10.1016/j.pep.2005.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Revised: 02/02/2005] [Indexed: 11/29/2022]
Abstract
The tri-functional enzyme of Saccharomyces cerevisiae dihydroneopterin aldolase (DHNA)-dihydropterin pyrophosphokinase (PPPK)-dihydropteroate synthase (DHPS) catalyzes three sequential steps in folate biosynthesis. A cDNA encoding the PPPK and DHPS domains of the tri-functional enzyme has been cloned. This bi-functional enzyme was expressed as a His(6) fusion protein in Escherichia coli and the protein was purified to apparent homogeneity. The purified protein possesses both PPPK and DHPS activities as measured by the incorporation of [(3)H]p-ABA into the appropriate substrate. The pH optimum of the DHPS activity was determined to be 8.5. Gel filtration measurement indicates that the protein exists as a dimer in solution. A robotic screening method was used to identify crystallization conditions. Bi-pyramidal crystals of the enzyme formed with the protein in the presence of a pterin substrate analog in phosphate buffer (pH 6.3) and these diffracted to 2.3A. Structural information from these crystals could be used to design novel drugs to inhibit folate biosynthesis.
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Yang M, Brazier M, Edwards R, Davis BG. High-throughput mass-spectrometry monitoring for multisubstrate enzymes: determining the kinetic parameters and catalytic activities of glycosyltransferases. Chembiochem 2005; 6:346-57. [PMID: 15678424 DOI: 10.1002/cbic.200400100] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A novel high-throughput screening (HTS) method with electrospray time-of-flight (ESI-TOF) mass spectrometry allows i) rapid and broad screening of multisubstrate enzyme catalytic activity towards a range of donor and acceptor substrates; ii) determination of full multisubstrate kinetic parameters and the binding order of substrates. Two representative glycosyltransferases (GTs, one common, one recently isolated, one O-glycosyltransferase (O-GT), one N-glycosyltransferase (N-GT)) have been used to validate this system: the widely used bovine beta-1,4-galactosyltransferase (EC 2.4.1.22), and the recently isolated Arabidopsis thaliana GT UGT72B1 (EC 2.4.1.-). The GAR (green/amber/red) broad-substrate-specificity screen, which is based on the mass ion abundance of product, provides a fast, high-throughput method for finding potential donors and acceptors from substrate libraries. This was evaluated by using six natural and non-natural donors (alpha-UDP-D-Glucose (UDPGlc), alpha-UDP-N-Acetyl-D-glucosamine (UDPGlcNAc), alpha-UDP-D-5-thioglucose (UDP5SGlc), alpha-GDP-L-fucose (GDPFuc), alpha-GDP-D-mannose (GDPMan), alpha,beta-UDP-D-mannose (UDPMan)) and 32 broad-ranging acceptors (sugars, plant hormones, antibiotics, flavonoids, coumarins, phenylpropanoids and benzoic acids). By using the fast-equilibrium assumption, KM, kcat and KIA were determined for representative substrates, and these values were used to determine substrate binding orders. These screening methods applied to the two very different enzymes revealed some unusual substrate specificities, thus highlighting the utility of broad-ranging substrate screening. For UGT72B1, it was shown that the donor specificity is determined largely by the nucleotide moiety. The method is therefore capable of identifying GT enzymes with usefully broad carbohydrate-transfer ability.
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Affiliation(s)
- Min Yang
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
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20
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Mustafa NR, Verpoorte R. Chorismate derived C6C1 compounds in plants. PLANTA 2005; 222:1-5. [PMID: 16049673 DOI: 10.1007/s00425-005-1554-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Accepted: 03/24/2005] [Indexed: 05/03/2023]
Affiliation(s)
- Natali Rianika Mustafa
- Section of Metabolomics, Institute of Biology, Leiden University, Einsteinweg 55, P.O. Box 9502, 2300 Leiden, The Netherlands
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21
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Lawrence MC, Iliades P, Fernley RT, Berglez J, Pilling PA, Macreadie IG. The three-dimensional structure of the bifunctional 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase/dihydropteroate synthase of Saccharomyces cerevisiae. J Mol Biol 2005; 348:655-70. [PMID: 15826662 DOI: 10.1016/j.jmb.2005.03.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 03/03/2005] [Accepted: 03/04/2005] [Indexed: 11/16/2022]
Abstract
In Saccharomyces cerevisiae and other fungi, the enzymes dihydroneopterin aldolase, 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) and dihydropteroate synthase (DHPS) are encoded by a polycistronic gene that is translated into a single polypeptide having all three functions. These enzymatic functions are essential to both prokaryotes and lower eukaryotes, and catalyse sequential reactions in folate biosynthesis. Deletion or disruption of either function leads to cell death. These enzymes are absent from mammals and thus make ideal antimicrobial targets. DHPS is currently the target of antifolate therapy for a number of infectious diseases, and its activity is inhibited by sulfonamides and sulfones. These drugs are typically used as part of a synergistic cocktail with the 2,4-diaminopyrimidines that inhibit dihydrofolate reductase. A gene encoding the S.cerevisiae HPPK and DHPS enzymes has been cloned and expressed in Escherichia coli. A complex of the purified bifunctional polypeptide with a pterin monophosphate substrate analogue has been crystallized, and its structure solved by molecular replacement and refined to 2.3A resolution. The polypeptide consists of two structural domains, each of which closely resembles its respective monofunctional bacterial HPPK and DHPS counterpart. The mode of ligand binding is similar to that observed in the bacterial enzymes. The association between the domains within the polypeptide as well as the quaternary association of the polypeptide via its constituent DHPS domains provide insight into the assembly of the trifunctional enzyme in S.cerevisiae and probably other fungal species.
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Affiliation(s)
- Michael C Lawrence
- CSIRO Health Sciences and Nutrition, 343 Royal Parade, Parkville, Victoria 3052, Australia.
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22
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Storozhenko S, Ravanel S, Zhang GF, Rébeillé F, Lambert W, Van Der Straeten D. Folate enhancement in staple crops by metabolic engineering. Trends Food Sci Technol 2005. [DOI: 10.1016/j.tifs.2005.03.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Jouhet J, Maréchal E, Baldan B, Bligny R, Joyard J, Block MA. Phosphate deprivation induces transfer of DGDG galactolipid from chloroplast to mitochondria. ACTA ACUST UNITED AC 2004; 167:863-74. [PMID: 15569715 PMCID: PMC2172463 DOI: 10.1083/jcb.200407022] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In many soils plants have to grow in a shortage of phosphate, leading to development of phosphate-saving mechanisms. At the cellular level, these mechanisms include conversion of phospholipids into glycolipids, mainly digalactosyldiacylglycerol (DGDG). The lipid changes are not restricted to plastid membranes where DGDG is synthesized and resides under normal conditions. In plant cells deprived of phosphate, mitochondria contain a high concentration of DGDG, whereas mitochondria have no glycolipids in control cells. Mitochondria do not synthesize this pool of DGDG, which structure is shown to be characteristic of a DGD type enzyme present in plastid envelope. The transfer of DGDG between plastid and mitochondria is investigated and detected between mitochondria-closely associated envelope vesicles and mitochondria. This transfer does not apparently involve the endomembrane system and would rather be dependent upon contacts between plastids and mitochondria. Contacts sites are favored at early stages of phosphate deprivation when DGDG cell content is just starting to respond to phosphate deprivation.
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Affiliation(s)
- Juliette Jouhet
- Laboratoire de Physiologie Cellulaire Végétale, UMR 5168 (CNRS/CEA/Université Jseph Fourier/INRA), DRDC-PCV, CEA-Grenoble, Grenoble, France
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Moore BD. Bifunctional and moonlighting enzymes: lighting the way to regulatory control. TRENDS IN PLANT SCIENCE 2004; 9:221-8. [PMID: 15130547 DOI: 10.1016/j.tplants.2004.03.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Affiliation(s)
- Brandon d Moore
- Department of Genetics, Biochemistry, and Life Science Studies, Clemson University, Clemson, SC 29634, USA.
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Giegé P, Heazlewood JL, Roessner-Tunali U, Millar AH, Fernie AR, Leaver CJ, Sweetlove LJ. Enzymes of glycolysis are functionally associated with the mitochondrion in Arabidopsis cells. THE PLANT CELL 2003; 15:2140-51. [PMID: 12953116 PMCID: PMC181336 DOI: 10.1105/tpc.012500] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2003] [Accepted: 06/24/2003] [Indexed: 05/17/2023]
Abstract
Mitochondria fulfill a wide range of metabolic functions in addition to the synthesis of ATP and contain a diverse array of proteins to perform these functions. Here, we present the unexpected discovery of the presence of the enzymes of glycolysis in a mitochondrial fraction of Arabidopsis cells. Proteomic analyses of this mitochondrial fraction revealed the presence of 7 of the 10 enzymes that constitute the glycolytic pathway. Four of these enzymes (glyceraldehyde-3-P dehydrogenase, aldolase, phosphoglycerate mutase, and enolase) were also identified in an intermembrane space/outer mitochondrial membrane fraction. Enzyme activity assays confirmed that the entire glycolytic pathway was present in preparations of isolated Arabidopsis mitochondria, and the sensitivity of these activities to protease treatments indicated that the glycolytic enzymes are present on the outside of the mitochondrion. The association of glycolytic enzymes with mitochondria was confirmed in vivo by the expression of enolase- and aldolase-yellow fluorescent protein fusions in Arabidopsis protoplasts. The yellow fluorescent protein fluorescence signal showed that these two fusion proteins are present throughout the cytosol but are also concentrated in punctate regions that colocalized with the mitochondrion-specific probe Mitotracker Red. Furthermore, when supplied with appropriate cofactors, isolated, intact mitochondria were capable of the metabolism of (13)C-glucose to (13)C-labeled intermediates of the trichloroacetic acid cycle, suggesting that the complete glycolytic sequence is present and active in this subcellular fraction. On the basis of these data, we propose that the entire glycolytic pathway is associated with plant mitochondria by attachment to the cytosolic face of the outer mitochondrial membrane and that this microcompartmentation of glycolysis allows pyruvate to be provided directly to the mitochondrion, where it is used as a respiratory substrate.
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Affiliation(s)
- Philippe Giegé
- Institut de Biologie Moléculaire des Plantes, Strasbourg 67084, France
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Jabrin S, Ravanel S, Gambonnet B, Douce R, Rébeillé F. One-carbon metabolism in plants. Regulation of tetrahydrofolate synthesis during germination and seedling development. PLANT PHYSIOLOGY 2003; 131:1431-9. [PMID: 12644692 PMCID: PMC166902 DOI: 10.1104/pp.016915] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2002] [Revised: 11/19/2002] [Accepted: 11/26/2002] [Indexed: 05/18/2023]
Abstract
Tetrahydrofolate (THF) is a central cofactor for one-carbon transfer reactions in all living organisms. In this study, we analyzed the expression of dihydropterin pyrophosphokinase-dihydropteroate synthase (HPPK-DHPS) in pea (Pisum sativum) organs during development, and so the capacity to synthesize dihydropteroate, an intermediate in the de novo THF biosynthetic pathway. During seedling development, all of the examined organs/tissues contain THF coenzymes, collectively termed folate, and express the HPPK-DHPS enzyme. This suggests that each organ/tissue is autonomous for the synthesis of THF. During germination, folate accumulates in cotyledons and embryos, but high amounts of HPPK-DHPS are only observed in embryos. During organ differentiation, folate is synthesized preferentially in highly dividing tissues and in photosynthetic leaves. This is associated with high levels of the HPPK-DHPS mRNA and protein, and a pool of folate 3- to 5-fold higher than in the rest of the plant. In germinating embryos and in meristematic tissues, the high capacity to synthesize and accumulate folate correlates with the general resumption of cell metabolism and the high requirement for nucleotide synthesis, major cellular processes involving folate coenzymes. The particular status of folate synthesis in leaves is related to light. Thus, when illuminated, etiolated leaves gradually accumulate the HPPK-DHPS enzyme and folate. This suggests that folate synthesis plays an important role in the transition from heterotrophic to photoautotrophic growth. Analysis of the intracellular distribution of folate in green and etiolated leaves indicates that the coenzymes accumulate mainly in the cytosol, where they can supply the high demand for methyl groups.
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Affiliation(s)
- Samuel Jabrin
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5019 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Joseph Fourier Grenoble I, Département Réponse et Dynamique Cellulaires, France
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