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Han S, Lin Y, Meng Y, Si C. Genome-Wide Identification and Analysis of SUS and AGPase Family Members in Sweet Potato: Response to Excessive Nitrogen Stress during Storage Root Formation. Int J Mol Sci 2024; 25:8236. [PMID: 39125807 PMCID: PMC11311812 DOI: 10.3390/ijms25158236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 08/12/2024] Open
Abstract
(1) The development of sweet potato storage roots is impacted by nitrogen (N) levels, with excessive nitrogen often impeding development. Starch synthesis enzymes such as sucrose synthase (SUS) and ADP-glucose pyrophosphorylase (AGPase) are pivotal in this context. Although the effects of excessive nitrogen on the formation of sweet potato storage roots are well documented, the specific responses of IbSUSs and IbAGPases have not been extensively reported on. (2) Pot experiments were conducted using the sweet potato cultivar "Pushu 32" at moderate (MN, 120 kg N ha-1) and excessive nitrogen levels (EN, 240 kg N ha-1). (3) Nine IbSUS and nine IbAGPase genes were categorized into three and two distinct subgroups based on phylogenetic analysis. Excessive nitrogen significantly (p < 0.05) suppressed the expression of IbAGPL1, IbAGPL2, IbAGPL4, IbAGPL5, IbAGPL6, IbAGPS1, and IbAGPS2 in fibrous roots and IbSUS2, IbSUS6, IbSUS7, IbSUS8, IbSUS9, IbAGPL2, and IbAGPL4 in storage roots, and then significantly (p < 0.05) decreased the SUS and AGPase activities and starch content of fibrous root and storage root, ultimately reducing the storage root formation of sweet potato. Excessive nitrogen extremely significantly (p < 0.01) enhanced the expression of IbAGPL3, which was strongly negatively correlated with the number and weight of storage roots per plant. (4) IbAGPL3 may be a key gene in the response to excessive nitrogen stress and modifying starch synthesis in sweet potato.
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Affiliation(s)
- Shaoxuan Han
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural, School of Rural Revitalization), Hainan University, Danzhou 571700, China; (S.H.); (Y.M.)
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572025, China
| | - Yanhui Lin
- Hainan Key Laboratory of Crop Genetics and Breeding, Institute of Food Crops, Hainan Academy of Agricultural Sciences, Haikou 571100, China;
| | - Yayi Meng
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural, School of Rural Revitalization), Hainan University, Danzhou 571700, China; (S.H.); (Y.M.)
| | - Chengcheng Si
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural, School of Rural Revitalization), Hainan University, Danzhou 571700, China; (S.H.); (Y.M.)
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572025, China
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2
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Characterization of Various Subunit Combinations of ADP-Glucose Pyrophosphorylase in Duckweed (Landoltia punctata). BIOMED RESEARCH INTERNATIONAL 2022; 2022:5455593. [PMID: 35309169 PMCID: PMC8927976 DOI: 10.1155/2022/5455593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/24/2022] [Indexed: 11/17/2022]
Abstract
Background Landoltia punctata can be used as renewable and sustainable biofuel feedstock because it can quickly accumulate high starch levels. ADP-glucose pyrophosphorylase (AGPase) catalyzes the first committed step during starch biosynthesis in higher plants. The heterotetrameric structure of plant AGPases comprises pairs of large subunits (LSs) and small subunits (SSs). Although several studies have reported on the high starch accumulation capacity of duckweed, no study has explored the underlying molecular accumulation mechanisms and their linkage with AGPase. Therefore, this study focused on characterizing the roles of different L. punctate AGPases. Methodology. Expression patterns of LpAGPs were determined through comparative transcriptome analyses, followed by coexpressing their coding sequences in Escherichia coli, Saccharomyces cerevisiae, Arabidopsis thaliana, and Nicotiana tabacum. Results Comparative transcriptome analyses showed that there are five AGPase subunits encoding cDNAs in L. punctata (LpAGPS1, LpAGPS2, LpAGPL1, LpAGPL2, and LpAGPL3). Nutrient starvation (distilled water treatment) significantly upregulated the expression of LpAGPS1, LpAGPL2, and LpAGPL3. Coexpression of LpAGPSs and LpAGPLs in Escherichia coli generated six heterotetramers, but only four (LpAGPS1/LpAGPL3, LpAGPS2/LpAGPL1, LpAGPS2/LpAGPL2, and LpAGPS2/LpAGPL3) exhibited AGPase activities and displayed a brownish coloration upon exposure to iodine staining. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays validated the interactions between LpAGPS1/LpAGPL2, LpAGPS1/LpAGPL3, LpAGPS2/LpAGPL1, LpAGPS2/LpAGPL2, and LpAGPS2/LpAGPL3. All the five LpAGPs were fusion-expressed with hGFP in Arabidopsis protoplasts, and their green fluorescence signals were uniformly localized in the chloroplast, indicating that they are plastid proteins. Conclusions This study uncovered the cDNA sequences, structures, subunit interactions, expression patterns, and subcellular localization of AGPase. Collectively, these findings provide new insights into the molecular mechanism of fast starch accumulation in L. punctata.
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Figueroa CM, Asencion Diez MD, Ballicora MA, Iglesias AA. Structure, function, and evolution of plant ADP-glucose pyrophosphorylase. PLANT MOLECULAR BIOLOGY 2022; 108:307-323. [PMID: 35006475 DOI: 10.1007/s11103-021-01235-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 12/15/2021] [Indexed: 05/25/2023]
Abstract
This review outlines research performed in the last two decades on the structural, kinetic, regulatory and evolutionary aspects of ADP-glucose pyrophosphorylase, the regulatory enzyme for starch biosynthesis. ADP-glucose pyrophosphorylase (ADP-Glc PPase) catalyzes the first committed step in the pathway of glycogen and starch synthesis in bacteria and plants, respectively. Plant ADP-Glc PPase is a heterotetramer allosterically regulated by metabolites and post-translational modifications. In this review, we focus on the three-dimensional structure of the plant enzyme, the amino acids that bind the regulatory molecules, and the regions involved in transmitting the allosteric signal to the catalytic site. We provide a model for the evolution of the small and large subunits, which produce heterotetramers with distinct catalytic and regulatory properties. Additionally, we review the various post-translational modifications observed in ADP-Glc PPases from different species and tissues. Finally, we discuss the subcellular localization of the enzyme found in grain endosperm from grasses, such as maize and rice. Overall, this work brings together research performed in the last two decades to better understand the multiple mechanisms involved in the regulation of ADP-Glc PPase. The rational modification of this enzyme could improve the yield and resilience of economically important crops, which is particularly important in the current scenario of climate change and food shortage.
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Affiliation(s)
- Carlos M Figueroa
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Bioquímica y Ciencias Biológicas, Santa Fe, Argentina
| | - Matías D Asencion Diez
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Bioquímica y Ciencias Biológicas, Santa Fe, Argentina
| | - Miguel A Ballicora
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, USA.
| | - Alberto A Iglesias
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Bioquímica y Ciencias Biológicas, Santa Fe, Argentina.
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4
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Alves FRR, Lira BS, Pikart FC, Monteiro SS, Furlan CM, Purgatto E, Pascoal GB, Andrade SCDS, Demarco D, Rossi M, Freschi L. Beyond the limits of photoperception: constitutively active PHYTOCHROME B2 overexpression as a means of improving fruit nutritional quality in tomato. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:2027-2041. [PMID: 32068963 PMCID: PMC7540714 DOI: 10.1111/pbi.13362] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 01/28/2020] [Accepted: 02/10/2020] [Indexed: 05/30/2023]
Abstract
Photoreceptor engineering has recently emerged as a means for improving agronomically beneficial traits in crop species. Despite the central role played by the red/far-red photoreceptor phytochromes (PHYs) in controlling fruit physiology, the applicability of PHY engineering for increasing fleshy fruit nutritional content remains poorly exploited. In this study, we demonstrated that the fruit-specific overexpression of a constitutively active GAF domain Tyr252 -to-His PHYB2 mutant version (PHYB2Y252H ) significantly enhances the accumulation of multiple health-promoting antioxidants in tomato fruits, without negative collateral consequences on vegetative development. Compared with the native PHYB2 overexpression, PHYB2Y252H -overexpressing lines exhibited more extensive increments in transcript abundance of genes associated with fruit plastid development, chlorophyll biosynthesis and metabolic pathways responsible for the accumulation of antioxidant compounds. Accordingly, PHYB2Y252H -overexpressing fruits developed more chloroplasts containing voluminous grana at the green stage and overaccumulated carotenoids, tocopherols, flavonoids and ascorbate in ripe fruits compared with both wild-type and PHYB2-overexpressing lines. The impacts of PHYB2 or PHYB2Y252H overexpression on fruit primary metabolism were limited to a slight promotion in lipid biosynthesis and reduction in sugar accumulation. Altogether, these findings indicate that mutation-based adjustments in PHY properties represent a valuable photobiotechnological tool for tomato biofortification, highlighting the potential of photoreceptor engineering for improving quality traits in fleshy fruits.
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Affiliation(s)
- Frederico Rocha Rodrigues Alves
- Departamento de BotânicaUniversidade de São PauloSão PauloSPBrazil
- Departamento de BotânicaUniversidade Federal de GoiásGoiásGOBrazil
| | | | | | | | | | - Eduardo Purgatto
- Departamento de Alimentos e Nutrição ExperimentalUniversidade de São PauloSão PauloSPBrazil
| | - Grazieli Benedetti Pascoal
- Departamento de Alimentos e Nutrição ExperimentalUniversidade de São PauloSão PauloSPBrazil
- Curso de Graduação em NutriçãoUniversidade Federal de UberlândiaMinas GeraisMGBrazil
| | | | - Diego Demarco
- Departamento de BotânicaUniversidade de São PauloSão PauloSPBrazil
| | - Magdalena Rossi
- Departamento de BotânicaUniversidade de São PauloSão PauloSPBrazil
| | - Luciano Freschi
- Departamento de BotânicaUniversidade de São PauloSão PauloSPBrazil
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5
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Cifuente JO, Comino N, D'Angelo C, Marina A, Gil-Carton D, Albesa-Jové D, Guerin ME. The allosteric control mechanism of bacterial glycogen biosynthesis disclosed by cryoEM. Curr Res Struct Biol 2020; 2:89-103. [PMID: 34235472 PMCID: PMC8244506 DOI: 10.1016/j.crstbi.2020.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/12/2020] [Accepted: 04/20/2020] [Indexed: 11/10/2022] Open
Abstract
Glycogen and starch are the major carbon and energy reserve polysaccharides in nature, providing living organisms with a survival advantage. The evolution of the enzymatic machinery responsible for the biosynthesis and degradation of such polysaccharides, led the development of mechanisms to control the assembly and disassembly rate, to store and recover glucose according to cell energy demands. The tetrameric enzyme ADP-glucose pyrophosphorylase (AGPase) catalyzes and regulates the initial step in the biosynthesis of both α-polyglucans. AGPase displays cooperativity and allosteric regulation by sensing metabolites from the cell energy flux. The understanding of the allosteric signal transduction mechanisms in AGPase arises as a long-standing challenge. In this work, we disclose the cryoEM structures of the paradigmatic homotetrameric AGPase from Escherichia coli (EcAGPase), in complex with either positive or negative physiological allosteric regulators, fructose-1,6-bisphosphate (FBP) and AMP respectively, both at 3.0 Å resolution. Strikingly, the structures reveal that FBP binds deeply into the allosteric cleft and overlaps the AMP site. As a consequence, FBP promotes a concerted conformational switch of a regulatory loop, RL2, from a "locked" to a "free" state, modulating ATP binding and activating the enzyme. This notion is strongly supported by our complementary biophysical and bioinformatics evidence, and a careful analysis of vast enzyme kinetics data on single-point mutants of EcAGPase. The cryoEM structures uncover the residue interaction networks (RIN) between the allosteric and the catalytic components of the enzyme, providing unique details on how the signaling information is transmitted across the tetramer, from which cooperativity emerges. Altogether, the conformational states visualized by cryoEM reveal the regulatory mechanism of EcAGPase, laying the foundations to understand the allosteric control of bacterial glycogen biosynthesis at the molecular level of detail.
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Key Words
- AGPase, ADP-glucose pyrophosphorylase
- AMP, adenosine 5′-monophosphate
- ATP, adenosine 5′-triphosphate
- EcAGPase, AGPase from E. coli
- Enzyme allosterism
- FBP, fructose 1,6-bisphosphate
- G1P, α-d-glucose-1-phosphate
- GBE, glycogen branching enzyme
- GDE, glycogen debranching enzyme
- GP, glycogen phosphorylase
- GS, glycogen synthase
- GTA-like, glycosyltransferase-A like domain
- Glycogen biosynthesis
- Glycogen regulation
- LβH, left-handed β-helix domain
- Nucleotide sugar biosynthesis
- PPi, pyrophosphate
- RIN, residue interaction network
- SM, sensory motif
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Affiliation(s)
- Javier O. Cifuente
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
| | - Natalia Comino
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
| | - Cecilia D'Angelo
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
| | - Alberto Marina
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
| | - David Gil-Carton
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
| | - David Albesa-Jové
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
| | - Marcelo E. Guerin
- Structural Biology Unit, CIC BioGUNE, Bizkaia Technology Park, 48160, Derio, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
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He R, Yu G, Han X, Han J, Li W, Wang B, Huang S, Cheng X. ThPP1 gene, encodes an inorganic pyrophosphatase in Thellungiella halophila, enhanced the tolerance of the transgenic rice to alkali stress. PLANT CELL REPORTS 2017; 36:1929-1942. [PMID: 29030650 DOI: 10.1007/s00299-017-2208-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 09/12/2017] [Indexed: 05/14/2023]
Abstract
An inorganic pyrophosphorylase gene, ThPP1 , modulated the accumulations of phosphate and osmolytes by up-regulating the differentially expression genes, thus enhancing the tolerance of the transgenic rice to alkali stress (AS). Inorganic pyrophosphorylase is essential in catalyzing the hydrolysis of pyrophosphate to inorganic phosphate during plant growth. Here, we report the changes of physiological osmolytes and differentially expression genes in the transgenic rice overexpressing a soluble inorganic pyrophosphatase gene ThPP1 of Thellungiella halophila in response to AS. Analyses showed that the ThPP1 gene was a PPase family I member which is located to the cytoplasm. Data showed that the transgenic lines revealed an enhanced tolerance to AS compared to the wild type, and effectively increased the accumulations of inorganic phosphate and organic small molecules starch, sucrose, proline and chlorophyll, and maintained the balance of osmotic potential by modulating the ratio of Na+/K+ in plant cells. Under AS, total 379 of differentially expression genes were up-regulated in the leaves of the transgenic line compared with control, and the enhanced tolerance of the transgenic rice to the AS seemed to be associated with the up-regulations of the osmotic stress-related genes such as the L-type lectin-domain containing receptor kinase (L-type LecRK), the cation/H+ antiporter gene and the vacuolar cation/proton exchanger 1 gene (CAX1), which conferred the involvements in the biosynthesis and metabolic pathways. Protein interaction showed that the ThPP1 protein specifically interacted with a 16# target partner of the photosystem II light-harvesting-Chl-binding protein. This study suggested that the ThPP1 gene plays an important regulatory role in conferring the tolerance of the transgenic rice to AS, and is an effective candidate in molecular breeding for crop cultivation of the alkali tolerance.
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Affiliation(s)
- Rui He
- College of Land and Environment, Shenyang Agricultural University, No. 120 Dongling Road, Shenyang, 110866, Liaoning, People's Republic of China
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China
| | - Guohong Yu
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China
| | - Xiaori Han
- College of Land and Environment, Shenyang Agricultural University, No. 120 Dongling Road, Shenyang, 110866, Liaoning, People's Republic of China
| | - Jiao Han
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China
- College of Life Science, Shanxi Normal University, No. 1 Gongyue Street, Yaodu Area, Linfen, 0410004, Shanxi, People's Republic of China
| | - Wei Li
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China
| | - Bing Wang
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China
| | - Shengcai Huang
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China
| | - Xianguo Cheng
- Key Lab of Plant Nutrition and Fertilizers, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, No. 12 South Street, Zhongguancun, Beijing, 100081, People's Republic of China.
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7
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Cifuente JO, Comino N, Madariaga-Marcos J, López-Fernández S, García-Alija M, Agirre J, Albesa-Jové D, Guerin ME. Structural Basis of Glycogen Biosynthesis Regulation in Bacteria. Structure 2016; 24:1613-22. [PMID: 27545622 DOI: 10.1016/j.str.2016.06.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 12/12/2022]
Abstract
ADP-glucose pyrophosphorylase (AGPase) catalyzes the rate-limiting step of bacterial glycogen and plant starch biosynthesis, the most common carbon storage polysaccharides in nature. A major challenge is to understand how AGPase activity is regulated by metabolites in the energetic flux within the cell. Here we report crystal structures of the homotetrameric AGPase from Escherichia coli in complex with its physiological positive and negative allosteric regulators, fructose-1,6-bisphosphate (FBP) and AMP, and sucrose in the active site. FBP and AMP bind to partially overlapping sites located in a deep cleft between glycosyltransferase A-like and left-handed β helix domains of neighboring protomers, accounting for the fact that sensitivity to inhibition by AMP is modulated by the concentration of the activator FBP. We propose a model in which the energy reporters regulate EcAGPase catalytic activity by intra-protomer interactions and inter-protomer crosstalk, with a sensory motif and two regulatory loops playing a prominent role.
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Affiliation(s)
- Javier O Cifuente
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain
| | - Natalia Comino
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain
| | - Julene Madariaga-Marcos
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain
| | - Sonia López-Fernández
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain
| | - Mikel García-Alija
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain
| | - Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, The University of York, YO10 5DD, UK
| | - David Albesa-Jové
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain; IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain.
| | - Marcelo E Guerin
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia, Spain; IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain.
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8
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Zhou YX, Chen YX, Tao X, Cheng XJ, Wang HY. Isolation and characterization of cDNAs and genomic DNAs encoding ADP-glucose pyrophosphorylase large and small subunits from sweet potato. Mol Genet Genomics 2015; 291:609-20. [PMID: 26499957 DOI: 10.1007/s00438-015-1134-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 10/16/2015] [Indexed: 11/29/2022]
Abstract
Sweet potato [Ipomoea batatas (L.) Lam.], the world's seventh most important food crop, is also a major industrial raw material for starch and ethanol production. In the plant starch biosynthesis pathway, ADP-glucose pyrophosphorylase (AGPase) catalyzes the first, rate-limiting step and plays a pivotal role in regulating this process. In spite of the importance of sweet potato as a starch source, only a few studies have focused on the molecular aspects of starch biosynthesis in sweet potato and almost no intensive research has been carried out on the AGPase gene family in this species. In this study, cDNAs encoding two small subunits (SSs) and four large subunits (LSs) of AGPase isoforms were cloned from sweet potato and the genomic organizations of the corresponding AGPase genes were elucidated. Expression pattern analysis revealed that the two SSs were constitutively expressed, whereas the four LSs displayed differential expression patterns in various tissues and at different developmental stages. Co-expression of SSs with different LSs in Escherichia coli yielded eight heterotetramers showing different catalytic activities. Interactions between different SSs and LSs were confirmed by a yeast two-hybrid experiment. Our findings provide comprehensive information about AGPase gene sequences, structures, expression profiles, and subunit interactions in sweet potato. The results can serve as a foundation for elucidation of molecular mechanisms of starch synthesis in tuberous roots, and should contribute to future regulation of starch biosynthesis to improve sweet potato starch yield.
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Affiliation(s)
- Yu-Xi Zhou
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Yu-Xiang Chen
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Xiang Tao
- Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, 610041, People's Republic of China
| | - Xiao-Jie Cheng
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Hai-Yan Wang
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China.
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9
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Structural comparison, substrate specificity, and inhibitor binding of AGPase small subunit from monocot and dicot: present insight and future potential. BIOMED RESEARCH INTERNATIONAL 2014; 2014:583606. [PMID: 25276800 PMCID: PMC4167649 DOI: 10.1155/2014/583606] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/08/2014] [Accepted: 04/21/2014] [Indexed: 11/18/2022]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is the first rate limiting enzyme of starch biosynthesis pathway and has been exploited as the target for greater starch yield in several plants. The structure-function analysis and substrate binding specificity of AGPase have provided enormous potential for understanding the role of specific amino acid or motifs responsible for allosteric regulation and catalytic mechanisms, which facilitate the engineering of AGPases. We report the three-dimensional structure, substrate, and inhibitor binding specificity of AGPase small subunit from different monocot and dicot crop plants. Both monocot and dicot subunits were found to exploit similar interactions with the substrate and inhibitor molecule as in the case of their closest homologue potato tuber AGPase small subunit. Comparative sequence and structural analysis followed by molecular docking and electrostatic surface potential analysis reveal that rearrangements of secondary structure elements, substrate, and inhibitor binding residues are strongly conserved and follow common folding pattern and orientation within monocot and dicot displaying a similar mode of allosteric regulation and catalytic mechanism. The results from this study along with site-directed mutagenesis complemented by molecular dynamics simulation will shed more light on increasing the starch content of crop plants to ensure the food security worldwide.
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Tuncel A, Kawaguchi J, Ihara Y, Matsusaka H, Nishi A, Nakamura T, Kuhara S, Hirakawa H, Nakamura Y, Cakir B, Nagamine A, Okita TW, Hwang SK, Satoh H. The rice endosperm ADP-glucose pyrophosphorylase large subunit is essential for optimal catalysis and allosteric regulation of the heterotetrameric enzyme. PLANT & CELL PHYSIOLOGY 2014; 55:1169-83. [PMID: 24747952 DOI: 10.1093/pcp/pcu057] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Although an alternative pathway has been suggested, the prevailing view is that starch synthesis in cereal endosperm is controlled by the activity of the cytosolic isoform of ADPglucose pyrophosphorylase (AGPase). In rice, the cytosolic AGPase isoform is encoded by the OsAGPS2b and OsAGPL2 genes, which code for the small (S2b) and large (L2) subunits of the heterotetrameric enzyme, respectively. In this study, we isolated several allelic missense and nonsense OsAGPL2 mutants by N-methyl-N-nitrosourea (MNU) treatment of fertilized egg cells and by TILLING (Targeting Induced Local Lesions in Genomes). Interestingly, seeds from three of the missense mutants (two containing T139I and A171V) were severely shriveled and had seed weight and starch content comparable with the shriveled seeds from OsAGPL2 null mutants. Results from kinetic analysis of the purified recombinant enzymes revealed that the catalytic and allosteric regulatory properties of these mutant enzymes were significantly impaired. The missense heterotetramer enzymes and the S2b homotetramer had lower specific (catalytic) activities and affinities for the activator 3-phosphoglycerate (3-PGA). The missense heterotetramer enzymes showed more sensitivity to inhibition by the inhibitor inorganic phosphate (Pi) than the wild-type AGPase, while the S2b homotetramer was profoundly tolerant to Pi inhibition. Thus, our results provide definitive evidence that starch biosynthesis during rice endosperm development is controlled predominantly by the catalytic activity of the cytoplasmic AGPase and its allosteric regulation by the effectors. Moreover, our results show that the L2 subunit is essential for both catalysis and allosteric regulatory properties of the heterotetramer enzyme.
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Affiliation(s)
- Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USAThese authors contributed equally to this work
| | - Joe Kawaguchi
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 JapanThese authors contributed equally to this work
| | - Yasuharu Ihara
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | | | - Aiko Nishi
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | | | - Satoru Kuhara
- Department of Genetic Resources Technology, Kyushu University, Fukuoka, 812-8581 Japan
| | - Hideki Hirakawa
- Kazusa DNA Research Institute, Department of Plant Genome Research, Kisarazu, Japan
| | - Yasunori Nakamura
- Faculty of Bioresource Sciences, Akita Prefectural University, Akita City, 010-0195 Japan
| | - Bilal Cakir
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Ai Nagamine
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USAFaculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Hikaru Satoh
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
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Seferoglu AB, Baris I, Morgil H, Tulum I, Ozdas S, Cevahir G, Kavakli IH. Transcriptional regulation of the ADP-glucose pyrophosphorylase isoforms in the leaf and the stem under long and short photoperiod in lentil. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 205-206:29-37. [PMID: 23498860 DOI: 10.1016/j.plantsci.2013.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 01/19/2013] [Accepted: 01/22/2013] [Indexed: 05/23/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is a key enzyme in plant starch biosynthesis. It contains large (LS) and small (SS) subunits encoded by two different genes. In this study, we explored the transcriptional regulation of both the LS and SS subunits of AGPase in stem and leaf under different photoperiods length in lentil. To this end, we first isolated and characterized different isoforms of the LS and SS of lentil AGPase and then we performed quantitative real time PCR (qPCR) to see the effect of photoperiod length on the transcription of the AGPase isforms under the different photoperiod regimes in lentil. Analysis of the qPCR results revealed that the transcription of different isoforms of the LSs and the SSs of lentil AGPase are differentially regulated when photoperiod shifted from long-day to short-day in stem and leaves. While transcript levels of LS1 and SS2 in leaf significantly decreased, overall transcript levels of SS1 increased in short-day regime. Our results indicated that day length affects the transcription of lentil AGPase isoforms differentially in stems and leaves most likely to supply carbon from the stem to other tissues to regulate carbon metabolism under short-day conditions.
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Affiliation(s)
- Ayse Bengisu Seferoglu
- Koc University, Department of Chemical and Biological Engineering, Rumeli Feneri Yolu, 34450 Sariyer, Istanbul, Turkey
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George GM, van der Merwe MJ, Nunes-Nesi A, Bauer R, Fernie AR, Kossmann J, Lloyd JR. Virus-induced gene silencing of plastidial soluble inorganic pyrophosphatase impairs essential leaf anabolic pathways and reduces drought stress tolerance in Nicotiana benthamiana. PLANT PHYSIOLOGY 2010; 154:55-66. [PMID: 20605913 PMCID: PMC2938153 DOI: 10.1104/pp.110.157776] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 07/02/2010] [Indexed: 05/18/2023]
Abstract
The role of pyrophosphate in primary metabolism is poorly understood. Here, we report on the transient down-regulation of plastid-targeted soluble inorganic pyrophosphatase in Nicotiana benthamiana source leaves. Physiological and metabolic perturbations were particularly evident in chloroplastic central metabolism, which is reliant on fast and efficient pyrophosphate dissipation. Plants lacking plastidial soluble inorganic pyrophosphatase (psPPase) were characterized by increased pyrophosphate levels, decreased starch content, and alterations in chlorophyll and carotenoid biosynthesis, while constituents like amino acids (except for histidine, serine, and tryptophan) and soluble sugars and organic acids (except for malate and citrate) remained invariable from the control. Furthermore, translation of Rubisco was significantly affected, as observed for the amounts of the respective subunits as well as total soluble protein content. These changes were concurrent with the fact that plants with reduced psPPase were unable to assimilate carbon to the same extent as the controls. Furthermore, plants with lowered psPPase exposed to mild drought stress showed a moderate wilting phenotype and reduced vitality, which could be correlated to reduced abscisic acid levels limiting stomatal closure. Taken together, the results suggest that plastidial pyrophosphate dissipation through psPPase is indispensable for vital plant processes.
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Affiliation(s)
| | | | | | | | | | | | - James R. Lloyd
- Institute of Plant Biotechnology, University of Stellenbosch, Matieland 7602, Stellenbosch, South Africa (G.M.G., M.J.v.d.M., R.B., J.K., J.R.L.); Max Planck Institute of Molecular Plant Physiology, D–14476 Potsdam-Golm, Germany (A.N.-N., A.R.F.)
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