1
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Maeda HA, de Oliveira MVV. VAS1-mediated nitrogen reshuffling in aromatic amino acid homeostasis. Trends Plant Sci 2024; 29:507-509. [PMID: 38480091 DOI: 10.1016/j.tplants.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 05/04/2024]
Abstract
Aromatic amino acids (AAAs) are essential for synthesis of proteins and numerous plant natural products, yet how plants maintain AAA homeostasis remains poorly understood. Wu et al. reported that the aminotransferase VAS1 plays a role in AAA homeostasis by transferring nitrogen from AAAs to non-proteinogenic amino acids, 3-carboxytyrosine and 3-carboxyphenylalanine.
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Affiliation(s)
- Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA.
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2
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Jung S, Maeda HA. Debottlenecking the DOPA 4,5-dioxygenase step with enhanced tyrosine supply boosts betalain production in Nicotiana benthamiana. Plant Physiol 2024:kiae166. [PMID: 38498597 DOI: 10.1093/plphys/kiae166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/26/2024] [Accepted: 02/26/2024] [Indexed: 03/20/2024]
Abstract
Synthetic biology provides emerging tools to produce valuable compounds in plant hosts as sustainable chemical production platforms. However, little is known about how supply and utilization of precursors is coordinated at the interface of plant primary and specialized metabolism, limiting our ability to efficiently produce high levels of target specialized metabolites in plants. L-Tyrosine is an aromatic amino acid precursor of diverse plant natural products including betalain pigments, which are used as the major natural food red colorants and more recently a visual marker for plant transformation. Here, we studied the impact of enhanced L-tyrosine supply on the production of betalain pigments by expressing arogenate dehydrogenase (TyrA) from table beet (Beta vulgaris, BvTyrAα), which has relaxed feedback inhibition by L-tyrosine. Unexpectedly, betalain levels were reduced when BvTyrAα was co-expressed with the betalain pathway genes in Nicotiana benthamiana leaves; L-tyrosine and 3,4-dihydroxy-L-phenylalanine (L-DOPA) levels were drastically elevated but not efficiently converted to betalains. An additional expression of L-DOPA 4,5-dioxygenase (DODA), but not CYP76AD1 or cyclo-DOPA 5-O-glucosyltransferase, together with BvTyrAα and the betalain pathway, drastically enhanced betalain production, indicating that DODA is a major rate-limiting step of betalain biosynthesis in this system. Learning from this initial test and further debottlenecking the DODA step maximized betalain yield to an equivalent or higher level than that in table beet. Our data suggest that balancing between enhanced supply ("push") and effective utilization ("pull") of precursor by alleviating a bottleneck step is critical in successful plant synthetic biology to produce high levels of target compounds.
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Affiliation(s)
- Soyoung Jung
- Department of Botany, University of Wisconsin-Madison, WI 53706 USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, WI 53706 USA
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3
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El-Azaz J, Moore B, Takeda-Kimura Y, Yokoyama R, Wijesingha Ahchige M, Chen X, Schneider M, Maeda HA. Coordinated regulation of the entry and exit steps of aromatic amino acid biosynthesis supports the dual lignin pathway in grasses. Nat Commun 2023; 14:7242. [PMID: 37945591 PMCID: PMC10636026 DOI: 10.1038/s41467-023-42587-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 10/16/2023] [Indexed: 11/12/2023] Open
Abstract
Vascular plants direct large amounts of carbon to produce the aromatic amino acid phenylalanine to support the production of lignin and other phenylpropanoids. Uniquely, grasses, which include many major crops, can synthesize lignin and phenylpropanoids from both phenylalanine and tyrosine. However, how grasses regulate aromatic amino acid biosynthesis to feed this dual lignin pathway is unknown. Here we show, by stable-isotope labeling, that grasses produce tyrosine >10-times faster than Arabidopsis without compromising phenylalanine biosynthesis. Detailed in vitro enzyme characterization and combinatorial in planta expression uncovered that coordinated expression of specific enzyme isoforms at the entry and exit steps of the aromatic amino acid pathway enables grasses to maintain high production of both tyrosine and phenylalanine, the precursors of the dual lignin pathway. These findings highlight the complex regulation of plant aromatic amino acid biosynthesis and provide novel genetic tools to engineer the interface of primary and specialized metabolism in plants.
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Affiliation(s)
- Jorge El-Azaz
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
| | - Bethany Moore
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
- Morgridge Institute for Research, Madison, WI, USA
| | - Yuri Takeda-Kimura
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
- Faculty of Agriculture, Yamagata University, Yamagata-shi, Japan
| | - Ryo Yokoyama
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Micha Wijesingha Ahchige
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Xuan Chen
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
- International Institute of Tea Industry Innovation for "one Belt, one Road", Nanjing Agricultural University, Nanjing, Jiangsu, PR China
| | - Matthew Schneider
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
- Cell Culture Company, Minneapolis, MN, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA.
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4
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Abstract
Aromatic aminotransferases (Aro ATs) are pyridoxal-5-phosphate (PLP)-dependent enzymes that catalyze the transamination reactions of an aromatic amino acid (AAA) or a keto acid. Aro ATs are involved in biosynthesis or degradation of AAAs and play important functions in controlling the production of plant hormones and secondary metabolites, such as auxin, tocopherols, flavonoids, and lignin. Most Aro ATs show substrate promiscuity and can accept multiple aromatic and non-aromatic amino and keto acid substrates, which complicates and limits our understanding of their in planta functions. Considering the critical roles Aro ATs play in plant primary and secondary metabolism, it is important to accurately determine substrate specificity and kinetic properties of Aro ATs. This chapter describes various methodologies of protein expression, purification and enzymatic assays, which can be used for biochemical characterization of Aro ATs.
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Affiliation(s)
- Kaan Koper
- Department of Botany, University of Wisconsin-Madison, Madison, WI, United States.
| | - Shogo Hataya
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Andrew G Hall
- Department of Botany, University of Wisconsin-Madison, Madison, WI, United States
| | - Taichi E Takasuka
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, United States.
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5
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de Raad M, Koper K, Deng K, Bowen BP, Maeda HA, Northen TR. Mass spectrometry imaging-based assays for aminotransferase activity reveal a broad substrate spectrum for a previously uncharacterized enzyme. J Biol Chem 2023; 299:102939. [PMID: 36702250 PMCID: PMC9957770 DOI: 10.1016/j.jbc.2023.102939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/25/2023] Open
Abstract
Aminotransferases (ATs) catalyze pyridoxal 5'-phosphate-dependent transamination reactions between amino donor and keto acceptor substrates and play central roles in nitrogen metabolism of all organisms. ATs are involved in the biosynthesis and degradation of both proteinogenic and nonproteinogenic amino acids and also carry out a wide variety of functions in photorespiration, detoxification, and secondary metabolism. Despite the importance of ATs, their functionality is poorly understood as only a small fraction of putative ATs, predicted from DNA sequences, are associated with experimental data. Even for characterized ATs, the full spectrum of substrate specificity, among many potential substrates, has not been explored in most cases. This is largely due to the lack of suitable high-throughput assays that can screen for AT activity and specificity at scale. Here we present a new high-throughput platform for screening AT activity using bioconjugate chemistry and mass spectrometry imaging-based analysis. Detection of AT reaction products is achieved by forming an oxime linkage between the ketone groups of transaminated amino donors and a probe molecule that facilitates mass spectrometry-based analysis using nanostructure-initiator mass spectrometry or MALDI-mass spectrometry. As a proof-of-principle, we applied the newly established method and found that a previously uncharacterized Arabidopsis thaliana tryptophan AT-related protein 1 is a highly promiscuous enzyme that can utilize 13 amino acid donors and three keto acid acceptors. These results demonstrate that this oxime-mass spectrometry imaging AT assay enables high-throughput discovery and comprehensive characterization of AT enzymes, leading to an accurate understanding of the nitrogen metabolic network.
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Affiliation(s)
- Markus de Raad
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.
| | - Kaan Koper
- Department of Botany, University of Wisconsin-Madison; Madison, Wisconsin, USA
| | - Kai Deng
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, California, USA; Sandia National Laboratories, Livermore, California, USA
| | - Benjamin P Bowen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison; Madison, Wisconsin, USA
| | - Trent R Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, California, USA; Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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Aharoni A, Maeda HA. Editorial overview: Plant metabolism without a border: The interface of primary and specialised metabolism. Curr Opin Plant Biol 2022; 69:102296. [PMID: 36108498 DOI: 10.1016/j.pbi.2022.102296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Asaph Aharoni
- Department of Plant & Environmental Sciences, Faculty of Biochemistry, Weizmann Institute of Science, P.O.B. 26, Rehovot, 7610001, Israel.
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA.
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7
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Huß S, Judd RS, Koper K, Maeda HA, Nikoloski Z. An automated workflow that generates atom mappings for large-scale metabolic models and its application to Arabidopsis thaliana. Plant J 2022; 111:1486-1500. [PMID: 35819300 DOI: 10.1111/tpj.15903] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Quantification of reaction fluxes of metabolic networks can help us understand how the integration of different metabolic pathways determines cellular functions. Yet, intracellular fluxes cannot be measured directly but are estimated with metabolic flux analysis (MFA), which relies on the patterns of isotope labeling of metabolites in the network. The application of MFA also requires a stoichiometric model with atom mappings that are currently not available for the majority of large-scale metabolic network models, particularly of plants. While automated approaches such as the Reaction Decoder Toolkit (RDT) can produce atom mappings for individual reactions, tracing the flow of individual atoms of the entire reactions across a metabolic model remains challenging. Here we establish an automated workflow to obtain reliable atom mappings for large-scale metabolic models by refining the outcome of RDT, and apply the workflow to metabolic models of Arabidopsis thaliana. We demonstrate the accuracy of RDT through a comparative analysis with atom mappings from a large database of biochemical reactions, MetaCyc. We further show the utility of our automated workflow by simulating 15 N isotope enrichment and identifying nitrogen (N)-containing metabolites which show enrichment patterns that are informative for flux estimation in future 15 N-MFA studies of A. thaliana. The automated workflow established in this study can be readily expanded to other species for which metabolic models have been established and the resulting atom mappings will facilitate MFA and graph-theoretic structural analyses with large-scale metabolic networks.
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Affiliation(s)
- Sebastian Huß
- Systems Biology and Mathematical Modelling Group, Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24- 25, 14476, Potsdam, Germany
| | - Rika Siedah Judd
- Department of Botany, University of Wisconsin-Madison, 430, Lincoln, Dr. Madison, Wisconsin, 53706, USA
| | - Kaan Koper
- Department of Botany, University of Wisconsin-Madison, 430, Lincoln, Dr. Madison, Wisconsin, 53706, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, 430, Lincoln, Dr. Madison, Wisconsin, 53706, USA
| | - Zoran Nikoloski
- Systems Biology and Mathematical Modelling Group, Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24- 25, 14476, Potsdam, Germany
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8
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Yokoyama R, de Oliveira MVV, Takeda-Kimura Y, Ishihara H, Alseekh S, Arrivault S, Kukshal V, Jez JM, Stitt M, Fernie AR, Maeda HA. Point mutations that boost aromatic amino acid production and CO 2 assimilation in plants. Sci Adv 2022; 8:eabo3416. [PMID: 35675400 PMCID: PMC9176744 DOI: 10.1126/sciadv.abo3416] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
Aromatic compounds having unusual stability provide high-value chemicals and considerable promise for carbon storage. Terrestrial plants can convert atmospheric CO2 into diverse and abundant aromatic compounds. However, it is unclear how plants control the shikimate pathway that connects the photosynthetic carbon fixation with the biosynthesis of aromatic amino acids, the major precursors of plant aromatic natural products. This study identified suppressor of tyra2 (sota) mutations that deregulate the first step in the plant shikimate pathway by alleviating multiple effector-mediated feedback regulation in Arabidopsis thaliana. The sota mutant plants showed hyperaccumulation of aromatic amino acids accompanied by up to a 30% increase in net CO2 assimilation. The identified mutations can be used to enhance plant-based, sustainable conversion of atmospheric CO2 to high-energy and high-value aromatic compounds.
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Affiliation(s)
- Ryo Yokoyama
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
| | | | | | - Hirofumi Ishihara
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Saleh Alseekh
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Stéphanie Arrivault
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Vandna Kukshal
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Joseph M. Jez
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Mark Stitt
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Alisdair R. Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Hiroshi A. Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
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9
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Koper K, Han SW, Pastor DC, Yoshikuni Y, Maeda HA. Evolutionary Origin and Functional Diversification of Aminotransferases. J Biol Chem 2022; 298:102122. [PMID: 35697072 PMCID: PMC9309667 DOI: 10.1016/j.jbc.2022.102122] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/30/2022] Open
Abstract
Aminotransferases (ATs) are pyridoxal 5′-phosphate–dependent enzymes that catalyze the transamination reactions between amino acid donor and keto acid acceptor substrates. Modern AT enzymes constitute ∼2% of all classified enzymatic activities, play central roles in nitrogen metabolism, and generate multitude of primary and secondary metabolites. ATs likely diverged into four distinct AT classes before the appearance of the last universal common ancestor and further expanded to a large and diverse enzyme family. Although the AT family underwent an extensive functional specialization, many AT enzymes retained considerable substrate promiscuity and multifunctionality because of their inherent mechanistic, structural, and functional constraints. This review summarizes the evolutionary history, diverse metabolic roles, reaction mechanisms, and structure–function relationships of the AT family enzymes, with a special emphasis on their substrate promiscuity and multifunctionality. Comprehensive characterization of AT substrate specificity is still needed to reveal their true metabolic functions in interconnecting various branches of the nitrogen metabolic network in different organisms.
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Affiliation(s)
- Kaan Koper
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Sang-Woo Han
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Yasuo Yoshikuni
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Global Center for Food, Land, and Water Resources, Research Faculty of Agriculture, Hokkaido University, Hokkaido 060-8589, Japan
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
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10
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Yokoyama R, Kleven B, Gupta A, Wang Y, Maeda HA. 3-Deoxy-D-arabino-heptulosonate 7-phosphate synthase as the gatekeeper of plant aromatic natural product biosynthesis. Curr Opin Plant Biol 2022; 67:102219. [PMID: 35550985 DOI: 10.1016/j.pbi.2022.102219] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/23/2022] [Accepted: 03/21/2022] [Indexed: 06/15/2023]
Abstract
The shikimate pathway connects the central carbon metabolism with the biosynthesis of aromatic amino acids-l-tyrosine, l-phenylalanine, and l-tryptophan-which play indispensable roles as precursors of numerous aromatic phytochemicals. Despite the importance of the shikimate pathway-derived products for both plant physiology and human society, the regulatory mechanism of the shikimate pathway remains elusive. This review summarizes the recent progress and current understanding on the plant 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHP synthase or DHS) enzymes that catalyze the committed reaction of the shikimate pathway. We particularly focus on how the DHS activity is regulated in plants in comparison to those of microbes and discuss potential roles of DHS as the critical gatekeeper for the production of plant aromatic compounds.
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Affiliation(s)
- Ryo Yokoyama
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA.
| | - Bailey Kleven
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Anika Gupta
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Yuer Wang
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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11
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Lopez-Nieves S, El-Azaz J, Men Y, Holland CK, Feng T, Brockington SF, Jez JM, Maeda HA. Two independently evolved natural mutations additively deregulate TyrA enzymes and boost tyrosine production in planta. Plant J 2022; 109:844-855. [PMID: 34807484 DOI: 10.1111/tpj.15597] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/29/2021] [Accepted: 11/15/2021] [Indexed: 06/13/2023]
Abstract
l-Tyrosine is an essential amino acid for protein synthesis and is also used in plants to synthesize diverse natural products. Plants primarily synthesize tyrosine via TyrA arogenate dehydrogenase (TyrAa or ADH), which are typically strongly feedback inhibited by tyrosine. However, two plant lineages, Fabaceae (legumes) and Caryophyllales, have TyrA enzymes that exhibit relaxed sensitivity to tyrosine inhibition and are associated with elevated production of tyrosine-derived compounds, such as betalain pigments uniquely produced in core Caryophyllales. Although we previously showed that a single D222N substitution is primarily responsible for the deregulation of legume TyrAs, it is unknown when and how the deregulated Caryophyllales TyrA emerged. Here, through phylogeny-guided TyrA structure-function analysis, we found that functionally deregulated TyrAs evolved early in the core Caryophyllales before the origin of betalains, where the E208D amino acid substitution in the active site, which is at a different and opposite location from D222N found in legume TyrAs, played a key role in the TyrA functionalization. Unlike legumes, however, additional substitutions on non-active site residues further contributed to the deregulation of TyrAs in Caryophyllales. The introduction of a mutation analogous to E208D partially deregulated tyrosine-sensitive TyrAs, such as Arabidopsis TyrA2 (AtTyrA2). Moreover, the combined introduction of D222N and E208D additively deregulated AtTyrA2, for which the expression in Nicotiana benthamiana led to highly elevated accumulation of tyrosine in planta. The present study demonstrates that phylogeny-guided characterization of key residues underlying primary metabolic innovations can provide powerful tools to boost the production of essential plant natural products.
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Affiliation(s)
- Samuel Lopez-Nieves
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Jorge El-Azaz
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Yusen Men
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Cynthia K Holland
- Department of Biology, Williams College, Williamstown, MA, 01267, USA
| | - Tao Feng
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | | | - Joseph M Jez
- Department of Biology, Washington University in St Louis, St Louis, MO, 63130, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
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12
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Yoo H, Shrivastava S, Lynch JH, Huang XQ, Widhalm JR, Guo L, Carter BC, Qian Y, Maeda HA, Ogas JP, Morgan JA, Marshall-Colón A, Dudareva N. Overexpression of arogenate dehydratase reveals an upstream point of metabolic control in phenylalanine biosynthesis. Plant J 2021; 108:737-751. [PMID: 34403557 DOI: 10.1111/tpj.15467] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Out of the three aromatic amino acids, the highest flux in plants is directed towards phenylalanine, which is utilized to synthesize proteins and thousands of phenolic metabolites contributing to plant fitness. Phenylalanine is produced predominantly in plastids via the shikimate pathway and subsequent arogenate pathway, both of which are subject to complex transcriptional and post-transcriptional regulation. Previously, it was shown that allosteric feedback inhibition of arogenate dehydratase (ADT), which catalyzes the final step of the arogenate pathway, restricts flux through phenylalanine biosynthesis. Here, we show that in petunia (Petunia hybrida) flowers, which typically produce high phenylalanine levels, ADT regulation is relaxed, but not eliminated. Moderate expression of a feedback-insensitive ADT increased flux towards phenylalanine, while high overexpression paradoxically reduced phenylalanine formation. This reduction could be partially, but not fully, recovered by bypassing other known metabolic flux control points in the aromatic amino acid network. Using comparative transcriptomics, reverse genetics, and metabolic flux analysis, we discovered that transcriptional regulation of the d-ribulose-5-phosphate 3-epimerase gene in the pentose phosphate pathway controls flux into the shikimate pathway. Taken together, our findings reveal that regulation within and upstream of the shikimate pathway shares control over phenylalanine biosynthesis in the plant cell.
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Affiliation(s)
- Heejin Yoo
- Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Dr, West Lafayette, IN, 47907-2010, USA
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
| | - Stuti Shrivastava
- Department of Plant Biology, University of Illinois Urbana-Champaign, 265 Morrill Hall, MC-116, Urbana, IL, 61801, USA
| | - Joseph H Lynch
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
| | - Xing-Qi Huang
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
| | - Joshua R Widhalm
- Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Dr, West Lafayette, IN, 47907-2010, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Longyun Guo
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
| | - Benjamin C Carter
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
| | - Yichun Qian
- Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Dr, West Lafayette, IN, 47907-2010, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Dr., Madison, WI, 53706, USA
| | - Joseph P Ogas
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - John A Morgan
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Dr., West Lafayette, IN, 47907-2100, USA
| | - Amy Marshall-Colón
- Department of Plant Biology, University of Illinois Urbana-Champaign, 265 Morrill Hall, MC-116, Urbana, IL, 61801, USA
| | - Natalia Dudareva
- Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Dr, West Lafayette, IN, 47907-2010, USA
- Department of Biochemistry, Purdue University, 175 South University St., West Lafayette, IN, 47907-2063, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
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13
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Gibbs NM, Su S, Lopez‐Nieves S, Mann S, Alban C, Maeda HA, Masson PH. Cadaverine regulates biotin synthesis to modulate primary root growth in Arabidopsis. Plant J 2021; 107:1283-1298. [PMID: 34250670 PMCID: PMC8518694 DOI: 10.1111/tpj.15417] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/23/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Cadaverine, a polyamine, has been linked to modification of root growth architecture and response to environmental stresses in plants. However, the molecular mechanisms that govern the regulation of root growth by cadaverine are largely unexplored. Here we conducted a forward genetic screen and isolated a mutation, cadaverine hypersensitive 3 (cdh3), which resulted in increased root-growth sensitivity to cadaverine, but not other polyamines. This mutation affects the BIO3-BIO1 biotin biosynthesis gene. Exogenous supply of biotin and a pathway intermediate downstream of BIO1, 7,8-diaminopelargonic acid, suppressed this cadaverine sensitivity phenotype. An in vitro enzyme assay showed cadaverine inhibits the BIO3-BIO1 activity. Furthermore, cadaverine-treated seedlings displayed reduced biotinylation of Biotin Carboxyl Carrier Protein 1 of the acetyl-coenzyme A carboxylase complex involved in de novo fatty acid biosynthesis, resulting in decreased accumulation of triacylglycerides. Taken together, these results revealed an unexpected role of cadaverine in the regulation of biotin biosynthesis, which leads to modulation of primary root growth of plants.
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Affiliation(s)
- Nicole M. Gibbs
- Laboratory of GeneticsUniversity of Wisconsin‐MadisonMadisonWI53706USA
- Present address:
Plant Molecular and Cellular Biology LaboratorySalk Institute for Biological StudiesLa JollaCA92037USA
| | - Shih‐Heng Su
- Laboratory of GeneticsUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | | | - Stéphane Mann
- Muséum National d'Histoire NaturelleUMR 7245CNRSMNHNMolécules de Communication et Adaptation des Micro‐organismesCP 5457 Rue CuvierParis75005France
| | - Claude Alban
- Université Grenoble AlpesINRAECEACNRSIRIGLPCVGrenoble38000France
| | - Hiroshi A. Maeda
- Department of BotanyUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | - Patrick H. Masson
- Laboratory of GeneticsUniversity of Wisconsin‐MadisonMadisonWI53706USA
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14
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Abstract
Tremendous chemical diversity is the hallmark of plants and is supported by highly complex biochemical machinery. Plant metabolic enzymes originated and were transferred from eukaryotic and prokaryotic ancestors and further diversified by the unprecedented rates of gene duplication and functionalization experienced in land plants. Unlike microbes, which have frequent horizontal gene transfer events and multiple inputs of energy and organic carbon, land plants predominantly rely on organic carbon generated from CO2 and have experienced very few, if any, gene transfers during their recent evolutionary history. As such, plant metabolic networks have evolved in a stepwise manner and on existing networks under various evolutionary constraints. This review aims to take a broader view of plant metabolic evolution and lay a framework to further explore evolutionary mechanisms of the complex metabolic network. Understanding the underlying metabolic and genetic constraints is also an empirical prerequisite for rational engineering and redesigning of plant metabolic pathways.
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Affiliation(s)
- Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA;
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany;
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15
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Yokoyama R, de Oliveira MVV, Kleven B, Maeda HA. The entry reaction of the plant shikimate pathway is subjected to highly complex metabolite-mediated regulation. Plant Cell 2021; 33:671-696. [PMID: 33955484 PMCID: PMC8136874 DOI: 10.1093/plcell/koaa042] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/19/2020] [Indexed: 05/22/2023]
Abstract
The plant shikimate pathway directs bulk carbon flow toward biosynthesis of aromatic amino acids (AAAs, i.e. tyrosine, phenylalanine, and tryptophan) and numerous aromatic phytochemicals. The microbial shikimate pathway is feedback inhibited by AAAs at the first enzyme, 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DHS). However, AAAs generally do not inhibit DHS activities from plant extracts and how plants regulate the shikimate pathway remains elusive. Here, we characterized recombinant Arabidopsis thaliana DHSs (AthDHSs) and found that tyrosine and tryptophan inhibit AthDHS2, but not AthDHS1 or AthDHS3. Mixing AthDHS2 with AthDHS1 or 3 attenuated its inhibition. The AAA and phenylpropanoid pathway intermediates chorismate and caffeate, respectively, strongly inhibited all AthDHSs, while the arogenate intermediate counteracted the AthDHS1 or 3 inhibition by chorismate. AAAs inhibited DHS activity in young seedlings, where AthDHS2 is highly expressed, but not in mature leaves, where AthDHS1 is predominantly expressed. Arabidopsis dhs1 and dhs3 knockout mutants were hypersensitive to tyrosine and tryptophan, respectively, while dhs2 was resistant to tyrosine-mediated growth inhibition. dhs1 and dhs3 also had reduced anthocyanin accumulation under high light stress. These findings reveal the highly complex regulation of the entry reaction of the plant shikimate pathway and lay the foundation for efforts to control the production of AAAs and diverse aromatic natural products in plants.
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Affiliation(s)
- Ryo Yokoyama
- Department of Botany, University of Wisconsin–Madison, 430 Lincoln Dr. Madison, WI 53706, USA
| | - Marcos V V de Oliveira
- Department of Botany, University of Wisconsin–Madison, 430 Lincoln Dr. Madison, WI 53706, USA
| | - Bailey Kleven
- Department of Botany, University of Wisconsin–Madison, 430 Lincoln Dr. Madison, WI 53706, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin–Madison, 430 Lincoln Dr. Madison, WI 53706, USA
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16
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Naake T, Maeda HA, Proost S, Tohge T, Fernie AR. Kingdom-wide analysis of the evolution of the plant type III polyketide synthase superfamily. Plant Physiol 2021; 185:857-875. [PMID: 33793871 PMCID: PMC8133574 DOI: 10.1093/plphys/kiaa086] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 12/07/2020] [Indexed: 05/19/2023]
Abstract
The emergence of type III polyketide synthases (PKSs) was a prerequisite for the conquest of land by the green lineage. Within the PKS superfamily, chalcone synthases (CHSs) provide the entry point reaction to the flavonoid pathway, while LESS ADHESIVE POLLEN 5 and 6 (LAP5/6) provide constituents of the outer exine pollen wall. To study the deep evolutionary history of this key family, we conducted phylogenomic synteny network and phylogenetic analyses of whole-genome data from 126 species spanning the green lineage including Arabidopsis thaliana, tomato (Solanum lycopersicum), and maize (Zea mays). This study thereby combined study of genomic location and context with changes in gene sequences. We found that the two major clades, CHS and LAP5/6 homologs, evolved early by a segmental duplication event prior to the divergence of Bryophytes and Tracheophytes. We propose that the macroevolution of the type III PKS superfamily is governed by whole-genome duplications and triplications. The combined phylogenetic and synteny analyses in this study provide insights into changes in the genomic location and context that are retained for a longer time scale with more recent functional divergence captured by gene sequence alterations.
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Affiliation(s)
- Thomas Naake
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin–Madison, 430 Lincoln Drive, Madison, WI 53706, USA
| | - Sebastian Proost
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Herestraat, 3000 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Campus Gasthuisberg, Rega Instituut, Herestraat, 3000 Leuven, Belgium
| | - Takayuki Tohge
- Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany
- Author for communication:
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17
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Schenck CA, Westphal J, Jayaraman D, Garcia K, Wen J, Mysore KS, Ané J, Sumner LW, Maeda HA. Role of cytosolic, tyrosine-insensitive prephenate dehydrogenase in Medicago truncatula. Plant Direct 2020; 4:e00218. [PMID: 32368714 PMCID: PMC7196213 DOI: 10.1002/pld3.218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/21/2020] [Accepted: 03/25/2020] [Indexed: 05/26/2023]
Abstract
l-Tyrosine (Tyr) is an aromatic amino acid synthesized de novo in plants and microbes downstream of the shikimate pathway. In plants, Tyr and a Tyr pathway intermediate, 4-hydroxyphenylpyruvate (HPP), are precursors to numerous specialized metabolites, which are crucial for plant and human health. Tyr is synthesized in the plastids by a TyrA family enzyme, arogenate dehydrogenase (ADH/TyrAa), which is feedback inhibited by Tyr. Additionally, many legumes possess prephenate dehydrogenases (PDH/TyrAp), which are insensitive to Tyr and localized to the cytosol. Yet the role of PDH enzymes in legumes is currently unknown. This study isolated and characterized Tnt1-transposon mutants of MtPDH1 (pdh1) in Medicago truncatula to investigate PDH function. The pdh1 mutants lacked PDH transcript and PDH activity, and displayed little aberrant morphological phenotypes under standard growth conditions, providing genetic evidence that MtPDH1 is responsible for the PDH activity detected in M. truncatula. Though plant PDH enzymes and activity have been specifically found in legumes, nodule number and nitrogenase activity of pdh1 mutants were not significantly reduced compared with wild-type (Wt) during symbiosis with nitrogen-fixing bacteria. Although Tyr levels were not significantly different between Wt and mutants under standard conditions, when carbon flux was increased by shikimate precursor feeding, mutants accumulated significantly less Tyr than Wt. These data suggest that MtPDH1 is involved in Tyr biosynthesis when the shikimate pathway is stimulated and possibly linked to unidentified legume-specific specialized metabolism.
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Affiliation(s)
- Craig A. Schenck
- Department of BotanyUniversity of Wisconsin‐MadisonMadisonWIUSA
- Present address:
Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMIUSA
| | - Josh Westphal
- Department of BotanyUniversity of Wisconsin‐MadisonMadisonWIUSA
| | | | - Kevin Garcia
- Department of BacteriologyUniversity of Wisconsin‐MadisonMadisonWIUSA
- Department of Crop and Soil SciencesNorth Carolina State UniversityRaleighNCUSA
| | | | | | - Jean‐Michel Ané
- Department of BacteriologyUniversity of Wisconsin‐MadisonMadisonWIUSA
- Department of AgronomyUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Lloyd W. Sumner
- Department of BiochemistryUniversity of MissouriColumbiaMOUSA
- Metabolomics and Bond Life Sciences CentersUniversity of MissouriColumbiaMOUSA
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18
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Abstract
Plants produce numerous natural products that are essential to both plant and human physiology. Recent identification of genes and enzymes involved in their biosynthesis now provides exciting opportunities to reconstruct plant natural product pathways in heterologous systems through synthetic biology. The use of plant chassis, although still in infancy, can take advantage of plant cells' inherent capacity to synthesize and store various phytochemicals. Also, large-scale plant biomass production systems, driven by photosynthetic energy production and carbon fixation, could be harnessed for industrial-scale production of natural products. However, little is known about which plants could serve as ideal hosts and how to optimize plant primary metabolism to efficiently provide precursors for the synthesis of desirable downstream natural products or specialized (secondary) metabolites. Although primary metabolism is generally assumed to be conserved, unlike the highly-diversified specialized metabolism, primary metabolic pathways and enzymes can differ between microbes and plants and also among different plants, especially at the interface between primary and specialized metabolisms. This review highlights examples of the diversity in plant primary metabolism and discusses how we can utilize these variations in plant synthetic biology. I propose that understanding the evolutionary, biochemical, genetic, and molecular bases of primary metabolic diversity could provide rational strategies for identifying suitable plant hosts and for further optimizing primary metabolism for sizable production of natural and bio-based products in plants.
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Affiliation(s)
- Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
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19
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Wang M, Toda K, Block A, Maeda HA. TAT1 and TAT2 tyrosine aminotransferases have both distinct and shared functions in tyrosine metabolism and degradation in Arabidopsis thaliana. J Biol Chem 2019; 294:3563-3576. [PMID: 30630953 PMCID: PMC6416433 DOI: 10.1074/jbc.ra118.006539] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/08/2019] [Indexed: 12/18/2022] Open
Abstract
Plants produce various l-tyrosine (Tyr)-derived compounds that are critical for plant adaptation and have pharmaceutical or nutritional importance for human health. Tyrosine aminotransferases (TATs) catalyze the reversible reaction between Tyr and 4-hydroxyphenylpyruvate (HPP), representing the entry point in plants for both biosynthesis of various natural products and Tyr degradation in the recycling of energy and nutrients. To better understand the roles of TATs and how Tyr is metabolized in planta, here we characterized single and double loss-of-function mutants of TAT1 (At5g53970) and TAT2 (At5g36160) in the model plant Arabidopsis thaliana As reported previously, tat1 mutants exhibited elevated and decreased levels of Tyr and tocopherols, respectively. The tat2 mutation alone had no impact on Tyr and tocopherol levels, but a tat1 tat2 double mutant had increased Tyr accumulation and decreased tocopherol levels under high-light stress compared with the tat1 mutant. Relative to WT and the tat2 mutant, the tat1 mutant displayed increased vulnerability to continuous dark treatment, associated with an early drop in respiratory activity and sucrose depletion. During isotope-labeled Tyr feeding in the dark, we observed that the tat1 mutant exhibits much slower 13C incorporation into tocopherols, fumarate, and other tricarboxylic acid (TCA) cycle intermediates than WT and the tat2 mutant. These results indicate that TAT1 and TAT2 function together in tocopherol biosynthesis, with TAT2 having a lesser role, and that TAT1 plays the major role in Tyr degradation in planta Our study also highlights the importance of Tyr degradation under carbon starvation conditions during dark-induced senescence in plants.
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Affiliation(s)
- Minmin Wang
- From the Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
- the Department of Biochemistry, University of Missouri, Columbia, Missouri 65211
| | - Kyoko Toda
- From the Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
- the Institute of Crop Science, National Agriculture and Food Research Organization (NARO), 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8518, Japan
| | - Anna Block
- the Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, Florida 32608, and
| | - Hiroshi A Maeda
- From the Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706,
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20
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de Oliveira MVV, Jin X, Chen X, Griffith D, Batchu S, Maeda HA. Imbalance of tyrosine by modulating TyrA arogenate dehydrogenases impacts growth and development of Arabidopsis thaliana. Plant J 2019; 97:901-922. [PMID: 30457178 DOI: 10.1111/tpj.14169] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 11/09/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
l-Tyrosine is an essential aromatic amino acid required for the synthesis of proteins and a diverse array of plant natural products; however, little is known on how the levels of tyrosine are controlled in planta and linked to overall growth and development. Most plants synthesize tyrosine by TyrA arogenate dehydrogenases, which are strongly feedback-inhibited by tyrosine and encoded by TyrA1 and TyrA2 genes in Arabidopsis thaliana. While TyrA enzymes have been extensively characterized at biochemical levels, their in planta functions remain uncertain. Here we found that TyrA1 suppression reduces seed yield due to impaired anther dehiscence, whereas TyrA2 knockout leads to slow growth with reticulate leaves. The tyra2 mutant phenotypes were exacerbated by TyrA1 suppression and rescued by the expression of TyrA2, TyrA1 or tyrosine feeding. Low-light conditions synchronized the tyra2 and wild-type growth, and ameliorated the tyra2 leaf reticulation. After shifting to normal light, tyra2 transiently decreased tyrosine and subsequently increased aspartate before the appearance of the leaf phenotypes. Overexpression of the deregulated TyrA enzymes led to hyper-accumulation of tyrosine, which was also accompanied by elevated aspartate and reticulate leaves. These results revealed that TyrA1 and TyrA2 have distinct and overlapping functions in flower and leaf development, respectively, and that imbalance of tyrosine, caused by altered TyrA activity and regulation, impacts growth and development of Arabidopsis. The findings provide critical bases for improving the production of tyrosine and its derived natural products, and further elucidating the coordinated metabolic and physiological processes to maintain tyrosine levels in plants.
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Affiliation(s)
- Marcos V V de Oliveira
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
| | - Xing Jin
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
| | - Xuan Chen
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
| | - Daniel Griffith
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
| | - Sai Batchu
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
- Department of Biology, The College of New Jersey, Biology Building, 2000 Pennington Road, Ewing, NJ, 08628, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
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21
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Lopez-Nieves S, Pringle A, Maeda HA. Biochemical characterization of TyrA dehydrogenases from Saccharomyces cerevisiae (Ascomycota) and Pleurotus ostreatus (Basidiomycota). Arch Biochem Biophys 2019; 665:12-19. [PMID: 30771296 DOI: 10.1016/j.abb.2019.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/06/2019] [Accepted: 02/12/2019] [Indexed: 12/30/2022]
Abstract
L-Tyrosine is an aromatic amino acid necessary for protein synthesis in all living organisms and a precursor of secondary (specialized) metabolites. In fungi, tyrosine-derived compounds are associated with virulence and defense (i.e. melanin production). However, how tyrosine is produced in fungi is not fully understood. Generally, tyrosine can be synthesized via two pathways: by prephenate dehydrogenase (TyrAp/PDH), a pathway found in most bacteria, or by arogenate dehydrogenase (TyrAa/ADH), a pathway found mainly in plants. Both enzymes require the cofactor NAD+ or NADP+ and typically are strongly feedback inhibited by tyrosine. Here, we biochemically characterized two TyrA enzymes from two distantly related fungi in the Ascomycota and Basidiomycota, Saccharomyces cerevisiae (ScTyrA/TYR1) and Pleurotus ostreatus (PoTyrA), respectively. We found that both enzymes favor the prephenate substrate and NAD+ cofactor in vitro. Interestingly, while PoTyrA was strongly inhibited by tyrosine, ScTyrA exhibited relaxed sensitivity to tyrosine inhibition. We further mutated ScTyrA at the amino acid residue that was previously shown to be involved in the substrate specificity of plant TyrAs; however, no changes in its substrate specificity were observed, suggesting that a different mechanism is involved in the TyrA substrate specificity of fungal TyrAs. The current findings provide foundational knowledge to further understand and engineer tyrosine-derived specialized pathways in fungi.
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Affiliation(s)
- Samuel Lopez-Nieves
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Anne Pringle
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
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22
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Smith SD, Angelovici R, Heyduk K, Maeda HA, Moghe GD, Pires JC, Widhalm JR, Wisecaver JH. The renaissance of comparative biochemistry. Am J Bot 2019; 106:3-13. [PMID: 30629738 DOI: 10.1002/ajb2.1216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Affiliation(s)
- Stacey D Smith
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Ruthie Angelovici
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
| | - Karolina Heyduk
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
| | - Gaurav D Moghe
- Plant Biology Section, School of Integrative Plant Sciences, Cornell University, Ithaca, NY, USA
| | - J Chris Pires
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
| | - Joshua R Widhalm
- Department of Horticulture and Landscape Architecture and Center for Plant Biology, Purdue University, West Lafayette, IN, USA
| | - Jennifer H Wisecaver
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, USA
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23
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Maeda HA. Evolutionary Diversification of Primary Metabolism and Its Contribution to Plant Chemical Diversity. Front Plant Sci 2019; 10:881. [PMID: 31354760 PMCID: PMC6635470 DOI: 10.3389/fpls.2019.00881] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/20/2019] [Indexed: 05/05/2023]
Abstract
Plants produce a diverse array of lineage-specific specialized (secondary) metabolites, which are synthesized from primary metabolites. Plant specialized metabolites play crucial roles in plant adaptation as well as in human nutrition and medicine. Unlike well-documented diversification of plant specialized metabolic enzymes, primary metabolism that provides essential compounds for cellular homeostasis is under strong selection pressure and generally assumed to be conserved across the plant kingdom. Yet, some alterations in primary metabolic pathways have been reported in plants. The biosynthetic pathways of certain amino acids and lipids have been altered in specific plant lineages. Also, two alternative pathways exist in plants for synthesizing primary precursors of the two major classes of plant specialized metabolites, terpenoids and phenylpropanoids. Such primary metabolic diversities likely underlie major evolutionary changes in plant metabolism and chemical diversity by acting as enabling or associated traits for the evolution of specialized metabolic pathways.
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24
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Timoneda A, Sheehan H, Feng T, Lopez-Nieves S, Maeda HA, Brockington S. Redirecting Primary Metabolism to Boost Production of Tyrosine-Derived Specialised Metabolites in Planta. Sci Rep 2018; 8:17256. [PMID: 30467357 PMCID: PMC6250739 DOI: 10.1038/s41598-018-33742-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 10/05/2018] [Indexed: 11/13/2022] Open
Abstract
L-Tyrosine-derived specialized metabolites perform many important functions in plants, and have valuable applications in human health and nutrition. A necessary step in the overproduction of specialised tyrosine-derived metabolites in planta is the manipulation of primary metabolism to enhance the availability of tyrosine. Here, we utilise a naturally occurring de-regulated isoform of the key enzyme, arogenate dehydrogenase, to re-engineer the interface of primary and specialised metabolism, to boost the production of tyrosine-derived pigments in a heterologous plant host. Through manipulation of tyrosine availability, we report a 7-fold increase in the production of tyrosine-derived betalain pigments, with an upper range of 855 mg·kg-1·FW, which compare favourably to many in vitro and commercial sources of betalain pigments. Since the most common plant pathway for tyrosine synthesis occurs via arogenate, the de-regulated arogenate dehydrogenase isoform is a promising route for enhanced production of tyrosine-derived pharmaceuticals in diverse plant hosts.
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Affiliation(s)
- Alfonso Timoneda
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Hester Sheehan
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Tao Feng
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Samuel Lopez-Nieves
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
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25
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Schenck CA, Maeda HA. Tyrosine biosynthesis, metabolism, and catabolism in plants. Phytochemistry 2018; 149:82-102. [PMID: 29477627 DOI: 10.1016/j.phytochem.2018.02.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/26/2018] [Accepted: 02/02/2018] [Indexed: 05/22/2023]
Abstract
L-Tyrosine (Tyr) is an aromatic amino acid (AAA) required for protein synthesis in all organisms, but synthesized de novo only in plants and microorganisms. In plants, Tyr also serves as a precursor of numerous specialized metabolites that have diverse physiological roles as electron carriers, antioxidants, attractants, and defense compounds. Some of these Tyr-derived plant natural products are also used in human medicine and nutrition (e.g. morphine and vitamin E). While the Tyr biosynthesis and catabolic pathways have been extensively studied in microbes and animals, respectively, those of plants have received much less attention until recently. Accumulating evidence suggest that the Tyr biosynthetic pathways differ between microbes and plants and even within the plant kingdom, likely to support the production of lineage-specific plant specialized metabolites derived from Tyr. The interspecies variations of plant Tyr pathway enzymes can now be used to enhance the production of Tyr and Tyr-derived compounds in plants and other synthetic biology platforms.
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Affiliation(s)
- Craig A Schenck
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA.
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26
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Lopez-Nieves S, Yang Y, Timoneda A, Wang M, Feng T, Smith SA, Brockington SF, Maeda HA. Relaxation of tyrosine pathway regulation underlies the evolution of betalain pigmentation in Caryophyllales. New Phytol 2018; 217:896-908. [PMID: 28990194 DOI: 10.1111/nph.14822] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/25/2017] [Indexed: 05/19/2023]
Abstract
Diverse natural products are synthesized in plants by specialized metabolic enzymes, which are often lineage-specific and derived from gene duplication followed by functional divergence. However, little is known about the contribution of primary metabolism to the evolution of specialized metabolic pathways. Betalain pigments, uniquely found in the plant order Caryophyllales, are synthesized from the aromatic amino acid l-tyrosine (Tyr) and replaced the otherwise ubiquitous phenylalanine-derived anthocyanins. This study combined biochemical, molecular and phylogenetic analyses, and uncovered coordinated evolution of Tyr and betalain biosynthetic pathways in Caryophyllales. We found that Beta vulgaris, which produces high concentrations of betalains, synthesizes Tyr via plastidic arogenate dehydrogenases (TyrAa /ADH) encoded by two ADH genes (BvADHα and BvADHβ). Unlike BvADHβ and other plant ADHs that are strongly inhibited by Tyr, BvADHα exhibited relaxed sensitivity to Tyr. Also, Tyr-insensitive BvADHα orthologs arose during the evolution of betalain pigmentation in the core Caryophyllales and later experienced relaxed selection and gene loss in lineages that reverted from betalain to anthocyanin pigmentation, such as Caryophyllaceae. These results suggest that relaxation of Tyr pathway regulation increased Tyr production and contributed to the evolution of betalain pigmentation, highlighting the significance of upstream primary metabolic regulation for the diversification of specialized plant metabolism.
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Affiliation(s)
- Samuel Lopez-Nieves
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ya Yang
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Plant and Microbial Biology, University of Minnesota-Twin Cities, St Paul, MN, USA
| | - Alfonso Timoneda
- Department of Plant and Microbial Biology, University of Minnesota-Twin Cities, St Paul, MN, USA
| | - Minmin Wang
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Tao Feng
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Stephen A Smith
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | | | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
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Schenck CA, Men Y, Maeda HA. Conserved Molecular Mechanism of TyrA Dehydrogenase Substrate Specificity Underlying Alternative Tyrosine Biosynthetic Pathways in Plants and Microbes. Front Mol Biosci 2017; 4:73. [PMID: 29164132 PMCID: PMC5681985 DOI: 10.3389/fmolb.2017.00073] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 10/24/2017] [Indexed: 12/03/2022] Open
Abstract
L-Tyrosine (Tyr) is an aromatic amino acid synthesized de novo in plants and microbes. In animals, Tyr must be obtained through their diet or synthesized from L-phenylalanine. In addition to protein synthesis, Tyr serves as the precursor of neurotransmitters (e.g., dopamine and epinephrine) in animals and of numerous plant natural products, which serve essential functions in both plants and humans (e.g., vitamin E and morphine). Tyr is synthesized via two alternative routes mediated by a TyrA family enzyme, prephenate, or arogenate dehydrogenase (PDH/TyrAp or ADH/TyrAa), typically found in microbes and plants, respectively. Although ADH activity is also found in some bacteria, the origin of arogenate-specific TyrAa enzymes is unknown. We recently identified an acidic Asp222 residue that confers ADH activity in plant TyrAs. In this study, structure-guided phylogenetic analyses identified bacterial homologs, closely-related to plant TyrAs, that also have an acidic 222 residue and ADH activity. A more distant archaeon TyrA that preferred PDH activity had a non-acidic Gln, whose substitution to Glu introduced ADH activity. These results indicate that the conserved molecular mechanism operated during the evolution of arogenate-specific TyrAa in both plants and microbes.
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Affiliation(s)
- Craig A Schenck
- Department of Botany, University of Wisconsin-Madison, Madison, WI, United States
| | - Yusen Men
- Department of Botany, University of Wisconsin-Madison, Madison, WI, United States
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, United States
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Schenck CA, Holland CK, Schneider MR, Men Y, Lee SG, Jez JM, Maeda HA. Molecular basis of the evolution of alternative tyrosine biosynthetic routes in plants. Nat Chem Biol 2017; 13:1029-1035. [PMID: 28671678 DOI: 10.1038/nchembio.2414] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/11/2017] [Indexed: 11/09/2022]
Abstract
L-Tyrosine (Tyr) is essential for protein synthesis and is a precursor of numerous specialized metabolites crucial for plant and human health. Tyr can be synthesized via two alternative routes by different key regulatory TyrA family enzymes, prephenate dehydrogenase (PDH, also known as TyrAp) or arogenate dehydrogenase (ADH, also known as TyrAa), representing a unique divergence of primary metabolic pathways. The molecular foundation underlying the evolution of these alternative Tyr pathways is currently unknown. Here we characterized recently diverged plant PDH and ADH enzymes, obtained the X-ray crystal structure of soybean PDH, and identified a single amino acid residue that defines TyrA substrate specificity and regulation. Structures of mutated PDHs co-crystallized with Tyr indicate that substitutions of Asn222 confer ADH activity and Tyr sensitivity. Reciprocal mutagenesis of the corresponding residue in divergent plant ADHs further introduced PDH activity and relaxed Tyr sensitivity, highlighting the critical role of this residue in TyrA substrate specificity that underlies the evolution of alternative Tyr biosynthetic pathways in plants.
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Affiliation(s)
- Craig A Schenck
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Cynthia K Holland
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Matthew R Schneider
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Yusen Men
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Soon Goo Lee
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
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29
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Wang M, Toda K, Maeda HA. Biochemical properties and subcellular localization of tyrosine aminotransferases in Arabidopsis thaliana. Phytochemistry 2016; 132:16-25. [PMID: 27726859 DOI: 10.1016/j.phytochem.2016.09.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/02/2016] [Accepted: 09/12/2016] [Indexed: 05/05/2023]
Abstract
Plants produce various L-tyrosine (Tyr)-derived compounds that are of pharmaceutical or nutritional importance to humans. Tyr aminotransferase (TAT) catalyzes the reversible transamination between Tyr and 4-hydroxyphenylpyruvate (HPP), the initial step in the biosynthesis of many Tyr-derived plant natural products. Herein reported is the biochemical characterization and subcellular localization of TAT enzymes from the model plant Arabidopsis thaliana. Phylogenetic analysis showed that Arabidopsis has at least two homologous TAT genes, At5g53970 (AtTAT1) and At5g36160 (AtTAT2). Their recombinant enzymes showed distinct biochemical properties: AtTAT1 had the highest activity towards Tyr, while AtTAT2 exhibited a broad substrate specificity for both amino and keto acid substrates. Also, AtTAT1 favored the direction of Tyr deamination to HPP, whereas AtTAT2 preferred transamination of HPP to Tyr. Subcellular localization analysis using GFP-fusion proteins and confocal microscopy showed that AtTAT1, AtTAT2, and HPP dioxygenase (HPPD), which catalyzes the subsequent step of TAT, are localized in the cytosol, unlike plastid-localized Tyr and tocopherol biosynthetic enzymes. Furthermore, subcellular fractionation indicated that, while HPPD activity is restricted to the cytosol, TAT activity is detected in both cytosolic and plastidic fractions of Arabidopsis leaf tissue, suggesting that an unknown aminotransferase(s) having TAT activity is also present in the plastids. Biochemical and cellular analyses of Arabidopsis TATs provide a fundamental basis for future in vivo studies and metabolic engineering for enhanced production of Tyr-derived phytochemicals in plants.
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Affiliation(s)
- Minmin Wang
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Kyoko Toda
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA; Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki, 305-8518, Japan.
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA.
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30
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Affiliation(s)
- Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, Wisconsin 53706, USA
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Schenck CA, Chen S, Siehl DL, Maeda HA. Non-plastidic, tyrosine-insensitive prephenate dehydrogenases from legumes. Nat Chem Biol 2015; 11:52-7. [PMID: 25402771 DOI: 10.1038/nchembio.1693] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 09/19/2014] [Indexed: 11/09/2022]
Abstract
L-Tyrosine (Tyr) and its plant-derived natural products are essential in both plants and humans. In plants, Tyr is generally assumed to be synthesized in the plastids via arogenate dehydrogenase (TyrA(a), also known also ADH), which is strictly inhibited by L-Tyr. Using phylogenetic and expression analyses, together with recombinant enzyme and endogenous activity assays, we identified prephenate dehydrogenases (TyrA(p)s, also known as PDHs) from two legumes, Glycine max (soybean) and Medicago truncatula. The identified PDHs were phylogenetically distinct from canonical plant ADH enzymes, preferred prephenate to arogenate substrate, localized outside of the plastids and were not inhibited by L-Tyr. The results provide molecular evidence for the diversification of primary metabolic Tyr pathway via an alternative cytosolic PDH pathway in plants.
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Affiliation(s)
- Craig A Schenck
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Siyu Chen
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, USA
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32
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Dornfeld C, Weisberg AJ, K C R, Dudareva N, Jelesko JG, Maeda HA. Phylobiochemical characterization of class-Ib aspartate/prephenate aminotransferases reveals evolution of the plant arogenate phenylalanine pathway. Plant Cell 2014; 26:3101-14. [PMID: 25070637 PMCID: PMC4145135 DOI: 10.1105/tpc.114.127407] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/21/2014] [Accepted: 07/03/2014] [Indexed: 05/22/2023]
Abstract
The aromatic amino acid Phe is required for protein synthesis and serves as the precursor of abundant phenylpropanoid plant natural products. While Phe is synthesized from prephenate exclusively via a phenylpyruvate intermediate in model microbes, the alternative pathway via arogenate is predominant in plant Phe biosynthesis. However, the molecular and biochemical evolution of the plant arogenate pathway is currently unknown. Here, we conducted phylogenetically informed biochemical characterization of prephenate aminotransferases (PPA-ATs) that belong to class-Ib aspartate aminotransferases (AspAT Ibs) and catalyze the first committed step of the arogenate pathway in plants. Plant PPA-ATs and succeeding arogenate dehydratases (ADTs) were found to be most closely related to homologs from Chlorobi/Bacteroidetes bacteria. The Chlorobium tepidum PPA-AT and ADT homologs indeed efficiently converted prephenate and arogenate into arogenate and Phe, respectively. A subset of AspAT Ib enzymes exhibiting PPA-AT activity was further identified from both Plantae and prokaryotes and, together with site-directed mutagenesis, showed that Thr-84 and Lys-169 play key roles in specific recognition of dicarboxylic keto (prephenate) and amino (aspartate) acid substrates. The results suggest that, along with ADT, a gene encoding prephenate-specific PPA-AT was transferred from a Chlorobi/Bacteroidetes ancestor to a eukaryotic ancestor of Plantae, allowing efficient Phe and phenylpropanoid production via arogenate in plants today.
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Affiliation(s)
- Camilla Dornfeld
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Alexandra J Weisberg
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Ritesh K C
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Natalia Dudareva
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - John G Jelesko
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
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Luby CH, Maeda HA, Goldman IL. Genetic and phenological variation of tocochromanol (vitamin E) content in wild (Daucus carota L. var. carota) and domesticated carrot (D. carota L. var. sativa). Hortic Res 2014; 1:14015. [PMID: 26504534 PMCID: PMC4596321 DOI: 10.1038/hortres.2014.15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/10/2014] [Accepted: 02/12/2014] [Indexed: 05/22/2023]
Abstract
Carrot roots (Daucus carota L. var. sativa) produce tocochromanol compounds, collectively known as vitamin E. However, little is known about their types and amounts. Here we determined the range and variation in types and amounts of tocochromanols in a variety of cultivated carrot accessions throughout carrot postharvest storage and reproductive stages and in wild-type roots (Daucus carota L. var. carota). Of eight possible tocochromanol compounds, we detected and quantified α-, and the combined peak for β- and γ- forms of tocopherols and tocotrienols. Significant variation in amounts of tocochromanol compounds was observed across accessions and over time. Large increases in α-tocopherol were noted during both reproductive growth and the postharvest stages. The variation of tocochromanols in carrot root tissue provides useful information for future research seeking to understand the role of these compounds in carrot root tissue or to breed varieties with increased levels of these compounds.
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Affiliation(s)
- Claire H Luby
- Department of Horticulture, University of Wisconsin-Madison, Madison WI 53706, USA
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison WI 53706, USA
| | - Irwin L Goldman
- Department of Horticulture, University of Wisconsin-Madison, Madison WI 53706, USA
- mailto:
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