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Decker D, Aubert J, Wilczynska M, Kleczkowski LA. Exploring Redox Modulation of Plant UDP-Glucose Pyrophosphorylase. Int J Mol Sci 2023; 24:ijms24108914. [PMID: 37240260 DOI: 10.3390/ijms24108914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
UDP-glucose (UDPG) pyrophosphorylase (UGPase) catalyzes a reversible reaction, producing UDPG, which serves as an essential precursor for hundreds of glycosyltransferases in all organisms. In this study, activities of purified UGPases from sugarcane and barley were found to be reversibly redox modulated in vitro through oxidation by hydrogen peroxide or oxidized glutathione (GSSG) and through reduction by dithiothreitol or glutathione. Generally, while oxidative treatment decreased UGPase activity, a subsequent reduction restored the activity. The oxidized enzyme had increased Km values with substrates, especially pyrophosphate. The increased Km values were also observed, regardless of redox status, for UGPase cysteine mutants (Cys102Ser and Cys99Ser for sugarcane and barley UGPases, respectively). However, activities and substrate affinities (Kms) of sugarcane Cys102Ser mutant, but not barley Cys99Ser, were still prone to redox modulation. The data suggest that plant UGPase is subject to redox control primarily via changes in the redox status of a single cysteine. Other cysteines may also, to some extent, contribute to UGPase redox status, as seen for sugarcane enzymes. The results are discussed with respect to earlier reported details of redox modulation of eukaryotic UGPases and regarding the structure/function properties of these proteins.
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Affiliation(s)
- Daniel Decker
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90187 Umeå, Sweden
| | - Juliette Aubert
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90187 Umeå, Sweden
| | | | - Leszek A Kleczkowski
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90187 Umeå, Sweden
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Dolan JP, Cosgrove SC, Miller GJ. Biocatalytic Approaches to Building Blocks for Enzymatic and Chemical Glycan Synthesis. JACS AU 2023; 3:47-61. [PMID: 36711082 PMCID: PMC9875253 DOI: 10.1021/jacsau.2c00529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
While the field of biocatalysis has bloomed over the past 20-30 years, advances in the understanding and improvement of carbohydrate-active enzymes, in particular, the sugar nucleotides involved in glycan building block biosynthesis, have progressed relatively more slowly. This perspective highlights the need for further insight into substrate promiscuity and the use of biocatalysis fundamentals (rational design, directed evolution, immobilization) to expand substrate scopes toward such carbohydrate building block syntheses and/or to improve enzyme stability, kinetics, or turnover. Further, it explores the growing premise of using biocatalysis to provide simple, cost-effective access to stereochemically defined carbohydrate materials, which can undergo late-stage chemical functionalization or automated glycan synthesis/polymerization.
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Effects of Magnesium, Pyrophosphate and Phosphonates on Pyrophosphorolytic Reaction of UDP-Glucose Pyrophosphorylase. PLANTS 2022; 11:plants11121611. [PMID: 35736762 PMCID: PMC9230926 DOI: 10.3390/plants11121611] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/05/2022] [Accepted: 06/14/2022] [Indexed: 12/03/2022]
Abstract
UDP-glucose pyrophosphorylase (UGPase) carries a freely reversible reaction, using glucose-1-P and UTP to produce UDP-glucose (UDPG) and pyrophosphate (PPi), with UDPG being essential for glycosylation reactions in all organisms including, e.g., synthesis of sucrose, cellulose and glycoproteins. In the present study, we found that free magnesium (Mg2+) had profound effects on the reverse reaction of purified barley UGPase, and was absolutely required for its activity, with an apparent Km of 0.13 mM. More detailed analyses with varied concentrations of MgPPi allowed us to conclude that it is the MgPPi complex which serves as true substrate for UGPase in its reverse reaction, with an apparent Km of 0.06 mM. Free PPi was an inhibitor in this reaction. Given the key role of PPi in the UGPase reaction, we have also tested possible effects of phosphonates, which are analogs of PPi and phosphate (Pi). Clodronate and etidronate (PPi analogs) had little or no effect on UGPase activity, whereas fosetyl-Al (Pi analog), a known fungicide, acted as effective near-competitive inhibitor versus PPi, with Ki of 0.15 mM. The data are discussed with respect to the role of magnesium in the UGPase reaction and elucidating the use of inhibitors in studies on cellular function of UGPase and related enzymes.
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Liu S, Zhong H, Wang Q, Liu C, Li T, Peng Z, Li Y, Zhang H, Liao J, Huang Y, Wang Z. Global Analysis of UDP Glucose Pyrophosphorylase (UDPGP) Gene Family in Plants: Conserved Evolution Involved in Cell Death. FRONTIERS IN PLANT SCIENCE 2021; 12:681719. [PMID: 34177996 PMCID: PMC8222925 DOI: 10.3389/fpls.2021.681719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/26/2021] [Indexed: 05/28/2023]
Abstract
UDP glucose pyrophosphorylase (UDPGP) family genes have been reported to play essential roles in cell death or individual survival. However, a systematic analysis on UDPGP gene family has not been performed yet. In this study, a total of 454 UDPGP proteins from 76 different species were analyzed. The analyses of the phylogenetic tree and orthogroups divided UDPGPs into three clades, including UDP-N-acetylglucosamine pyrophosphorylase (UAP), UDP-glucose pyrophosphorylase (UGP, containing UGP-A and UGP-B), and UDP-sugar pyrophosphorylase (USP). The evolutionary history of the UDPGPs indicated that the members of UAP, USP, and UGP-B were relatively conserved while varied in UGP-A. Homologous sequences of UGP-B and USP were found only in plants. The expression profile of UDPGP genes in Oryza sativa was mainly motivated under jasmonic acid (JA), abscisic acid (ABA), cadmium, and cold treatments, indicating that UDPGPs may play an important role in plant development and environment endurance. The key amino acids regulating the activity of UDPGPs were analyzed, and almost all of them were located in the NB-loop, SB-loop, or conserved motifs. Analysis of the natural variants of UDPGPs in rice revealed that only a few missense mutants existed in coding sequences (CDSs), and most of the resulting variations were located in the non-motif sites, indicating the conserved structure and function of UDPGPs in the evolution. Furthermore, alternative splicing may play a key role in regulating the activity of UDPGPs. The spatial structure prediction, enzymatic analysis, and transgenic verification of UAP isoforms illustrated that the loss of N- and C-terminal sequences did not affect the overall 3D structures, but the N- and C-terminal sequences are important for UAP genes to maintain their enzymatic activity. These results revealed a conserved UDPGP gene family and provided valuable information for further deep functional investigation of the UDPGP gene family in plants.
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Affiliation(s)
- Shuai Liu
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Hua Zhong
- State Key Laboratory of Hybrid Rice, Key Laboratory for Research and Utilization of Heterosis in Indica Rice, Ministry of Agriculture, College of Life Sciences, Wuhan University, Wuhan, China
| | - Qiang Wang
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education of the People’s Republic of China, Jiangxi Agricultural University, Nanchang, China
- Key Laboratory of Agriculture Responding to Climate Change, Jiangxi Agricultural University, Nanchang, China
| | - Caixiang Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy of Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, China
| | - Ting Li
- Youth League Committee, Jiangxi Agricultural University, Nanchang, China
| | - Zhaohua Peng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Yangsheng Li
- State Key Laboratory of Hybrid Rice, Key Laboratory for Research and Utilization of Heterosis in Indica Rice, Ministry of Agriculture, College of Life Sciences, Wuhan University, Wuhan, China
| | - Hongyu Zhang
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education of the People’s Republic of China, Jiangxi Agricultural University, Nanchang, China
- Key Laboratory of Agriculture Responding to Climate Change, Jiangxi Agricultural University, Nanchang, China
| | - Jianglin Liao
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education of the People’s Republic of China, Jiangxi Agricultural University, Nanchang, China
- Key Laboratory of Agriculture Responding to Climate Change, Jiangxi Agricultural University, Nanchang, China
| | - Yingjin Huang
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education of the People’s Republic of China, Jiangxi Agricultural University, Nanchang, China
- Key Laboratory of Agriculture Responding to Climate Change, Jiangxi Agricultural University, Nanchang, China
| | - Zhaohai Wang
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education of the People’s Republic of China, Jiangxi Agricultural University, Nanchang, China
- Key Laboratory of Agriculture Responding to Climate Change, Jiangxi Agricultural University, Nanchang, China
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Muhseen ZT, Ahmad S, Li G. Structural basis of UDP-N-acetylglucosamine pyrophosphorylase and identification of promising terpenes to control Aedes aegypti. Colloids Surf B Biointerfaces 2021; 204:111820. [PMID: 33964525 DOI: 10.1016/j.colsurfb.2021.111820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 10/21/2022]
Abstract
According to the world health organization (WHO) 2020 report, vector borne diseases account for 17 % of all infections with reported 700 thousand death each year. They are of considerable importance to health professionals as they are posing a serious health threat and include dengue fever, Zika fever, chikungunya, yellow fever, and other disease agents. Aedes aegypti serve as a vector for transmitting several of these tropical fevers. In the present study, UDP-N-acetylglucosamine pyrophosphorylase enzyme (Aa-UAP) of A. aegypti which plays a significant contribution in chitin metabolism is targeted with natural terpenes to propose an eco-friendly and novel candidates for the development of new insecticides. The three dimensional Aa-UAP structure was constructed via a comparative homology approach and validated, followed by structure-based virtual screening against 1000 terpenes collected from natural MDP3 and NPACT databases. Top hits were subjected to molecular dynamics (MD) simulations and binding free energies analysis to elucidate complex intermolecular stability and affinity over simulated time. The results demonstrated that Aa-UAP possesses a homodimer state and its active site residues are well conserved. Three compounds (NPACT00138, NPACT00452, and NPACT00839) were prioritized as they are establishing conserved and stable interactions with the active binding-site residues of Aa-UAP. Conclusively, the reported Aa-UAP specific terpenes could serve as promising leads in order to develop potential insecticides. Importantly, the FDA approved drug NPACT00839 (Paclitaxel) could be used further in the fast-track experimental testing pipeline for biological optimization.
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Affiliation(s)
- Ziyad Tariq Muhseen
- Key Laboratory of Ministry of Education for Medicinal Plant Resource and Natural Pharmaceutical Chemistry, Shaanxi Normal University, Xi'an, China; School of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Sajjad Ahmad
- Department of Health and Biological Sciences, Abasyn University, Peshawar, Pakistan
| | - Guanglin Li
- Key Laboratory of Ministry of Education for Medicinal Plant Resource and Natural Pharmaceutical Chemistry, Shaanxi Normal University, Xi'an, China; School of Life Sciences, Shaanxi Normal University, Xi'an, China.
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6
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Zhang W, Qin W, Li H, Wu AM. Biosynthesis and Transport of Nucleotide Sugars for Plant Hemicellulose. FRONTIERS IN PLANT SCIENCE 2021; 12:723128. [PMID: 34868108 PMCID: PMC8636097 DOI: 10.3389/fpls.2021.723128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 10/22/2021] [Indexed: 05/13/2023]
Abstract
Hemicellulose is entangled with cellulose through hydrogen bonds and meanwhile acts as a bridge for the deposition of lignin monomer in the secondary wall. Therefore, hemicellulose plays a vital role in the utilization of cell wall biomass. Many advances in hemicellulose research have recently been made, and a large number of genes and their functions have been identified and verified. However, due to the diversity and complexity of hemicellulose, the biosynthesis and regulatory mechanisms are yet unknown. In this review, we summarized the types of plant hemicellulose, hemicellulose-specific nucleotide sugar substrates, key transporters, and biosynthesis pathways. This review will contribute to a better understanding of substrate-level regulation of hemicellulose synthesis.
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Affiliation(s)
- Wenjuan Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
| | - Wenqi Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
| | - Huiling Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
| | - Ai-min Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory of Lingnan Modern Agriculture, Guangzhou, China
- *Correspondence: Ai-min Wu,
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7
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Minen RI, Martinez MP, Iglesias AA, Figueroa CM. Biochemical characterization of recombinant UDP-sugar pyrophosphorylase and galactinol synthase from Brachypodium distachyon. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 155:780-788. [PMID: 32866791 DOI: 10.1016/j.plaphy.2020.08.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Raffinose (Raf) protects plant cells during seed desiccation and under different abiotic stress conditions. The biosynthesis of Raf starts with the production of UDP-galactose by UDP-sugar pyrophosphorylase (USPPase) and continues with the synthesis of galactinol by galactinol synthase (GolSase). Galactinol is then used by Raf synthase to produce Raf. In this work, we report the biochemical characterization of USPPase (BdiUSPPase) and GolSase 1 (BdiGolSase1) from Brachypodium distachyon. The catalytic efficiency of BdiUSPPase was similar with galactose 1-phosphate and glucose 1-phosphate, but 5- to 17-fold lower with other sugar 1-phosphates. The catalytic efficiency of BdiGolSase1 with UDP-galactose was three orders of magnitude higher than with UDP-glucose. A structural model of BdiGolSase1 allowed us to determine the residues putatively involved in the binding of substrates. Among these, we found that Cys261 lies within the putative catalytic pocket. BdiGolSase1 was inactivated by oxidation with diamide and H2O2. The activity of the diamide-oxidized enzyme was recovered by reduction with dithiothreitol or E. coli thioredoxin, suggesting that BdiGolSase1 is redox-regulated.
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Affiliation(s)
- Romina I Minen
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, Santa Fe, Argentina
| | - María P Martinez
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, Santa Fe, Argentina
| | - Alberto A Iglesias
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, Santa Fe, Argentina
| | - Carlos M Figueroa
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, Santa Fe, Argentina.
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8
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Gogoi P, Mordina P, Kanaujia SP. Exploiting the rationale behind substrate recognition by promiscuous thermophilic NDP-sugar pyrophosphorylase for expanding glycorandomization: an in silico study. J Biomol Struct Dyn 2020; 39:6099-6111. [PMID: 32692307 DOI: 10.1080/07391102.2020.1796795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The fundamental substrates for protein glycosylation are provided by a group of enzymes known as NDP-sugar pyrophosphorylases (NSPases) which utilize nucleotide triphosphate (NTP) and sugar 1-phosphate to catalyze the formation of nucleotide diphospho-sugar (NDP-sugar). The promiscuous nature of NSPases is often exploited during chemoenzymatic glycorandomization in the pursuit of novel therapeutics. However, till date, the number of inherently promiscuous NSPases reported and the rationale behind their promiscuity is meager. In this study, we have identified a set of NSPases from a hyperthermophilic archaeon Pyrococcus horikoshii OT3 to identify probable candidates for glycorandomization. We identified a set of NSPases that include both substrate-specific and substrate-promiscuous NSPases with a visible predominance of the latter group. The rationale behind the promiscuity (or specificity) vividly lies in the repertoire of amino acid residues that assemble the active site for recognition of the substrate moiety. Furthermore, the absence of a function-specific auxiliary domain promotes substrate promiscuity in NSPases. This study, thus, provides a novel set of thermophilic NSPases that can be employed for chemoenzymatic glycorandomization. More importantly, identification of the residues that render substrate promiscuity (or specificity) would assist in sequence-based rational engineering of NSPases for enhanced glycorandomization. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Prerana Gogoi
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Prerana Mordina
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Shankar Prasad Kanaujia
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
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9
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Optimization of nucleotide sugar supply for polysaccharide formation via thermodynamic buffering. Biochem J 2020; 477:341-356. [PMID: 31967651 DOI: 10.1042/bcj20190807] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023]
Abstract
Plant polysaccharides (cellulose, hemicellulose, pectin, starch) are either direct (i.e. leaf starch) or indirect products of photosynthesis, and they belong to the most abundant organic compounds in nature. Although each of these polymers is made by a specific enzymatic machinery, frequently in different cell locations, details of their synthesis share certain common features. Thus, the production of these polysaccharides is preceded by the formation of nucleotide sugars catalyzed by fully reversible reactions of various enzymes, mostly pyrophosphorylases. These 'buffering' enzymes are, generally, quite active and operate close to equilibrium. The nucleotide sugars are then used as substrates for irreversible reactions of various polysaccharide-synthesizing glycosyltransferases ('engine' enzymes), e.g. plastidial starch synthases, or plasma membrane-bound cellulose synthase and callose synthase, or ER/Golgi-located variety of glycosyltransferases forming hemicellulose and pectin backbones. Alternatively, the irreversible step might also be provided by a carrier transporting a given immediate precursor across a membrane. Here, we argue that local equilibria, established within metabolic pathways and cycles resulting in polysaccharide production, bring stability to the system via the arrangement of a flexible supply of nucleotide sugars. This metabolic system is itself under control of adenylate kinase and nucleoside-diphosphate kinase, which determine the availability of nucleotides (adenylates, uridylates, guanylates and cytidylates) and Mg2+, the latter serving as a feedback signal from the nucleotide metabolome. Under these conditions, the supply of nucleotide sugars to engine enzymes is stable and constant, and the metabolic process becomes optimized in its load and consumption, making the system steady and self-regulated.
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Decker D, Kleczkowski LA. UDP-Sugar Producing Pyrophosphorylases: Distinct and Essential Enzymes With Overlapping Substrate Specificities, Providing de novo Precursors for Glycosylation Reactions. FRONTIERS IN PLANT SCIENCE 2019; 9:1822. [PMID: 30662444 PMCID: PMC6329318 DOI: 10.3389/fpls.2018.01822] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/23/2018] [Indexed: 05/02/2023]
Abstract
Nucleotide sugars are the key precursors for all glycosylation reactions and are required both for oligo- and polysaccharides synthesis and protein and lipid glycosylation. Among all nucleotide sugars, UDP-sugars are the most important precursors for biomass production in nature (e.g., synthesis of cellulose, hemicellulose, and pectins for cell wall production). Several recent studies have already suggested a potential role for UDP-Glc in plant growth and development, and UDP-Glc has also been suggested as a signaling molecule, in addition to its precursor function. In this review, we will cover primary mechanisms of formation of UDP-sugars, by focusing on UDP-sugar metabolizing pyrophosphorylases. The pyrophosphorylases can be divided into three families: UDP-Glc pyrophosphorylase (UGPase), UDP-sugar pyrophosphorylase (USPase), and UDP-N-acetyl glucosamine pyrophosphorylase (UAGPase), which can be distinguished both by their amino acid sequences and by differences in substrate specificity. Substrate specificities of these enzymes are discussed, along with structure-function relationships, based on their crystal structures and homology modeling. Earlier studies with transgenic plants have revealed that each of the pyrophosphorylases is essential for plant survival, and their loss or a decrease in activity results in reproductive impairment. This constitutes a problem when studying exact in vivo roles of the enzymes using classical reverse genetics approaches. Thus, strategies involving the use of specific inhibitors (reverse chemical genetics) are also discussed. Further characterization of the properties/roles of pyrophosphorylases should address fundamental questions dealing with mechanisms and control of carbohydrate synthesis and may allow to identify targets for manipulation of biomass production in plants.
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Affiliation(s)
| | - Leszek A. Kleczkowski
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå, Sweden
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11
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Enzyme and microbial technology for synthesis of bioactive oligosaccharides: an update. Appl Microbiol Biotechnol 2018; 102:3017-3026. [PMID: 29476402 DOI: 10.1007/s00253-018-8839-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 02/02/2018] [Accepted: 02/05/2018] [Indexed: 12/28/2022]
Abstract
Oligosaccharides, in either free or bound forms, play crucial roles in a wide range of biological processes. Increasing appreciation of their roles in cellular communication, interaction, pathogenesis, and prebiotic functions has stimulated tremendous interests in their synthesis. Pure and structurally defined oligosaccharides are essential for fundamental studies. On the other hand, for those with near term medical and nutraceutical applications, their large-scale synthesis is necessary. Unfortunately, oligosaccharides are notoriously difficult in their synthesis, and their enormous diverse structures leave a vast gap between what have been synthesized in laboratory and those present in various biological systems. While enzymes and microbes are nature's catalysts for oligosaccharides, their effective use is not without challenges. Using examples of galactose-containing oligosaccharides, this review analyzes the pros and cons of these two forms of biocatalysts and provides an updated view on the status of biocatalysis in this important field. Over the past few years, a large number of novel galactosidases were discovered and/or engineered for improved synthesis via transglycosylation. The use of salvage pathway for regeneration of uridine diphosphate (UDP)-galactose has made the use of Leloir glycosyltransferases simpler and more efficient. The recent success of large-scale synthesis of 2' fucosyllactose heralded the power of whole-cell biocatalysis as a scalable technology. While it still lags behind enzyme catalysis in terms of the number of oligosaccharides synthesized, an acceleration in the use of this form of biocatalyst is expected as rapid advances in synthetic biology have made the engineering of whole cell biocatalysts less arduous and less time consuming.
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12
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Decker D, Öberg C, Kleczkowski LA. The structure-activity relationship of the salicylimide derived inhibitors of UDP-sugar producing pyrophosphorylases. PLANT SIGNALING & BEHAVIOR 2018; 13:e1507406. [PMID: 30125142 PMCID: PMC6149491 DOI: 10.1080/15592324.2018.1507406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 07/31/2018] [Indexed: 05/18/2023]
Abstract
UDP-sugars are key precursors for biomass production in nature (synthesis of cellulose, hemicellulose, etc.). They are produced de novo by distinct UDP-sugar producing pyrophosphorylases. Studies on the roles of these enzymes using genetic knockouts were hampered by sterility of the mutants and by functional-complementation from related enzyme(s), hindering clear interpretation of the results. In an attempt to override these difficulties, we turned to the reverse chemical genetics approaches to identify compounds which interfere with the activity of those enzymes in vivo. Hit expansion on one of such compounds, a salicylimide derivative, allowed us to identify several inhibitors with a range of activities. The present study provides a structure-activity relationship for these compounds.
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Affiliation(s)
- Daniel Decker
- Department of Plant Physiology, Umeå Plant Science Center, Umeå University, Umeå, Sweden
- CONTACT Leszek A. Kleczkowski Department of Plant Physiology, Umeå Plant Science Center, Umeå University, 90187 Umeå, Sweden
| | - Christopher Öberg
- Laboratories for Chemical Biology Umeå, Department of Chemistry, Umeå University, Umeå, Sweden
| | - Leszek A. Kleczkowski
- Department of Plant Physiology, Umeå Plant Science Center, Umeå University, Umeå, Sweden
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Janse van Rensburg HC, Van den Ende W. UDP-Glucose: A Potential Signaling Molecule in Plants? FRONTIERS IN PLANT SCIENCE 2017; 8:2230. [PMID: 29375604 PMCID: PMC5767297 DOI: 10.3389/fpls.2017.02230] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 12/19/2017] [Indexed: 05/07/2023]
Abstract
This perspective paper focuses on the most recent results suggesting a potential role for UDP-Glucose as a signaling molecule in plants. In animals, UDP-Glucose is well-established as an extracellular signaling molecule that is sensed by G-protein coupled receptors, activating several downstream defense mechanisms. Recent studies have shown that abnormal growth occurred in both vegetative and reproductive tissue of plants with reduced UDP-Glucose levels, and this could be rescued by exogenous UDP-Glucose. In plants with increased biomass accumulation, the genes involved in UDP-Glucose production were up-regulated. However, excessive endogenous accumulation of UDP-Glucose induced programmed cell death (PCD), and this could also be obtained by exogenous UDP-Glucose application. Plants with decreased UDP-glucose were insensitive to pathogen induced PCD. We speculate that UDP-Glucose acts as an extracellular signaling molecule in plants, and that it may be perceived as a damage-associated molecular pattern.
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