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Chao M, Zhang Q, Huang L, Wang L, Dong J, Kou S, Song W, Wang T. ADP-glucose pyrophosphorylase gene family in soybean and implications in drought stress tolerance. Genes Genomics 2024; 46:1183-1199. [PMID: 39214924 DOI: 10.1007/s13258-024-01558-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 08/12/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND ADP-glucose pyrophosphorylase (AGPase) is the key rate-limiting enzyme in starch biosynthesis pathway, and has been identified as a potential target for manipulation strategies aimed at improving crop yield and quality. OBJECTIVE To identify the AGPase gene family members in soybean, and explore the potential implications of GmAGPS2 in drought stress tolerance. METHODS The genome-wide identification and sequence analysis of soybean AGPase gene family was carried out by bioinformatics methods. The GmAGP gene expression was analyzed using transcriptome data and quantitative real-time PCR (qRT-PCR). Furthermore, transgenic yeast strains overexpressing GmAGPS2 were generated, and their growth was observed under drought stress. RESULTS In this study, we searched for AGPase genes (GmAGP) in the soybean genome and identified a total of 14 GmAGP genes. The GmAGP proteins had a unique conserved NTP_transferase domain and were mainly located in the chloroplast and cytosol. Evolutionarily, the GmAGP proteins can be clustered into two distinct subgroups; within the same subgroup, they displayed a similar distribution pattern of conserved motifs. The GmAGP genes exhibited an uneven distribution on 10 chromosomes, and segmental duplication contributed to AGPase gene family expansion in soybean. The GmAGP genes presented different tissue expression pattern, in which GmAGPL6, GmAGPL9, and GmAGPL10 mainly exhibited tissue-specific expression pattern. The promoter of GmAGP genes had multiple cis-acting elements related to phytohormones and stress responses, and 8 GmAGP genes contained drought-responsive cis-acting elements. qRT‒PCR analysis demonstrated a significant upregulation expression of GmAGPL6, GmAGPL10, and GmAGPS2 in response to drought stress. Further functional analysis indicated that GmAGPS2 gene could improve yeast growth under drought stress conditions and enhance the drought tolerance of yeast. CONCLUSION These results will contribute to further elucidation of the function of GmAGP genes, and offer important candidate genes for the genetic improvement of starch and yield-related traits and the breeding of high drought stress tolerance varieties in soybean.
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Affiliation(s)
- Maoni Chao
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China.
| | - Qiufang Zhang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China
| | - Ling Huang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China
| | - Li Wang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China
| | - Jie Dong
- College of Agronomy, Shandong Agricultural University, Tai'an, 271018, China
| | - Shibo Kou
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China
| | - Weifeng Song
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China
| | - Tiegu Wang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China.
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Cifuente JO, Colleoni C, Kalscheuer R, Guerin ME. Architecture, Function, Regulation, and Evolution of α-Glucans Metabolic Enzymes in Prokaryotes. Chem Rev 2024; 124:4863-4934. [PMID: 38606812 PMCID: PMC11046441 DOI: 10.1021/acs.chemrev.3c00811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Bacteria have acquired sophisticated mechanisms for assembling and disassembling polysaccharides of different chemistry. α-d-Glucose homopolysaccharides, so-called α-glucans, are the most widespread polymers in nature being key components of microorganisms. Glycogen functions as an intracellular energy storage while some bacteria also produce extracellular assorted α-glucans. The classical bacterial glycogen metabolic pathway comprises the action of ADP-glucose pyrophosphorylase and glycogen synthase, whereas extracellular α-glucans are mostly related to peripheral enzymes dependent on sucrose. An alternative pathway of glycogen biosynthesis, operating via a maltose 1-phosphate polymerizing enzyme, displays an essential wiring with the trehalose metabolism to interconvert disaccharides into polysaccharides. Furthermore, some bacteria show a connection of intracellular glycogen metabolism with the genesis of extracellular capsular α-glucans, revealing a relationship between the storage and structural function of these compounds. Altogether, the current picture shows that bacteria have evolved an intricate α-glucan metabolism that ultimately relies on the evolution of a specific enzymatic machinery. The structural landscape of these enzymes exposes a limited number of core catalytic folds handling many different chemical reactions. In this Review, we present a rationale to explain how the chemical diversity of α-glucans emerged from these systems, highlighting the underlying structural evolution of the enzymes driving α-glucan bacterial metabolism.
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Affiliation(s)
- Javier O. Cifuente
- Instituto
Biofisika (UPV/EHU, CSIC), University of
the Basque Country, E-48940 Leioa, Spain
| | - Christophe Colleoni
- University
of Lille, CNRS, UMR8576-UGSF -Unité de Glycobiologie Structurale
et Fonctionnelle, F-59000 Lille, France
| | - Rainer Kalscheuer
- Institute
of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Marcelo E. Guerin
- Structural
Glycobiology Laboratory, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish
National Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac 4-8, Tower R, 08028 Barcelona, Catalonia, Spain
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Ma X, Ouyang X, Liu D, Zhang A. The 218th amino acid change of Ser to Ala in TaAGPS-7A increases enzyme activity and grain weight in bread wheat. THE CROP JOURNAL 2022. [DOI: 10.1016/j.cj.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Liang G, Li Y, Wang P, Jiao S, Wang H, Mao J, Chen B. VaAPL1 Promotes Starch Synthesis to Constantly Contribute to Soluble Sugar Accumulation, Improving Low Temperature Tolerance in Arabidopsis and Tomato. FRONTIERS IN PLANT SCIENCE 2022; 13:920424. [PMID: 35812933 PMCID: PMC9257282 DOI: 10.3389/fpls.2022.920424] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/02/2022] [Indexed: 05/30/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is a key rate-limiting enzyme involved in starch synthesis. APL1, an AGPase large subunit, plays an important role in the growth and development of grapes; however, its function in withstanding low temperature (LT) remains elusive. Hence, VaAPL1 was cloned from Vitis amurensis (Zuoshan I), and its function was characterized. The gene was highly expressed in the phloem of V. amurensis during winter dormancy (0, -5, and - 10°C). Phylogenetic relationships demonstrated that VaAPL1 was closely genetic related to SlAPL1 (from Solanum lycopersicum), and clustered into I group. Further, VaAPL1 was ectopically expressed in Arabidopsis thaliana (ecotype Columbia, Col) and tomato ("Micro-Tom" tomato) to characterize its function under LT. Compared with Col, the average survival rate of VaAPL1-overexpressing A. thaliana exceeded 75.47% after freezing treatment. Moreover, reactive oxygen species (ROS) content decreased in VaAPL1-overexpressing A. thaliana and tomato plants under LT stress. The activities of AGPase, and starch contents in VaAPL1-overexpressing A. thaliana were higher than in Col after LT stress. The contents of sucrose and glucose were accumulated in overexpressing plants compared with wild-type at 0 h and 24 h after LT stress. Transcriptome sequencing of overexpressing tomato plants revealed involvement in sugar metabolism and the hormone signal pathway, and Ca2+ signaling pathway-related genes were up-regulated. Hence, these results suggest that overexpression of VaAPL1 not only ensured sufficient starch converting into soluble sugars to maintain cell osmotic potential and provided energy, but also indirectly activated signal pathways involved in LT to enhance plant tolerance.
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5
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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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6
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Mukherjee S, Koramutla MK, Levin DB, Ayele BT. Genetic variation in transcriptional regulation of wheat seed starch content and its conversion to bioethanol. Food Energy Secur 2021. [DOI: 10.1002/fes3.339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Shalini Mukherjee
- Department of Plant Science University of Manitoba Winnipeg Manitoba Canada
| | | | - David B. Levin
- Department of Biosystems Engineering University of Manitoba Winnipeg Manitoba Canada
| | - Belay T. Ayele
- Department of Plant Science University of Manitoba Winnipeg Manitoba Canada
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Appenroth KJ, Ziegler P, Sree KS. Accumulation of starch in duckweeds (Lemnaceae), potential energy plants. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:2621-2633. [PMID: 34924714 PMCID: PMC8639912 DOI: 10.1007/s12298-021-01100-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/23/2021] [Accepted: 11/05/2021] [Indexed: 06/12/2023]
Abstract
Starch can accumulate in both actively growing vegetative fronds and over-wintering propagules, or turions of duckweeds, small floating aquatic plants belonging to the family of the Lemnaceae. The starch synthesizing potential of 36 duckweed species varies enormously, and the starch contents actually occurring in the duckweed tissues are determined by growth conditions, various types of stress and the action of growth regulators. The present review examines the effects of phytohormones and growth retardants, heavy metals, nutrient deficiency and salinity on the accumulation of starch in duckweeds with a view to obtaining high yields of starch as a feedstock for biofuel production. Biotechnological approaches to degrading duckweed starch to its component sugars and the fermentation of these sugars to bio-alcohols are also discussed.
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Affiliation(s)
- Klaus-J. Appenroth
- Matthias Schleiden Institute – Plant Physiology, University of Jena, Jena, Germany
| | - Paul Ziegler
- Department of Plant Physiology, University of Bayreuth, Bayreuth, Germany
| | - K. Sowjanya Sree
- Department of Environmental Science, Central University of Kerala, Tejaswini Hills, Periye, 671320 India
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de Freitas KEJ, dos Santos RS, Busanello C, de Carvalho Victoria F, Lopes JL, Wing RA, de Oliveira AC. Starch Synthesis-Related Genes (SSRG) Evolution in the Genus Oryza. PLANTS 2021; 10:plants10061057. [PMID: 34070565 PMCID: PMC8229393 DOI: 10.3390/plants10061057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 04/14/2021] [Accepted: 04/14/2021] [Indexed: 11/18/2022]
Abstract
Cooking quality is an important attribute in Common/Asian rice (Oryzasativa L.) varieties, being highly dependent on grain starch composition. This composition is known to be highly dependent on a cultivar’s genetics, but the way in which their genes express different phenotypes is not well understood. Further analysis of variation of grain quality genes using new information obtained from the wild relatives of rice should provide important insights into the evolution and potential use of these genetic resources. All analyses were conducted using bioinformatics approaches. The analysis of the protein sequences of grain quality genes across the Oryza suggest that the deletion/mutation of amino acids in active sites result in variations that can negatively affect specific steps of starch biosynthesis in the endosperm. On the other hand, the complete deletion of some genes in the wild species may not affect the amylose content. Here we present new insights for Starch Synthesis-Related Genes (SSRGs) evolution from starch-specific rice phenotypes.
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Affiliation(s)
- Karine E. Janner de Freitas
- Centro de desenvolvimento Tecnológico—CDTec, Graduate Program in biotechnology, Capão do Leão Campus, Federal de Pelotas, Pelotas 96160, Brazil; (K.E.J.d.F.); (C.B.); (J.L.L.)
| | | | - Carlos Busanello
- Centro de desenvolvimento Tecnológico—CDTec, Graduate Program in biotechnology, Capão do Leão Campus, Federal de Pelotas, Pelotas 96160, Brazil; (K.E.J.d.F.); (C.B.); (J.L.L.)
| | - Filipe de Carvalho Victoria
- Núcleo de Estudos da Vegetação Antártica—NEVA, Campus São Gabriel Federal do Pampa (UNIPAMPA), São Gabriel 97030, Brazil;
| | - Jennifer Luz Lopes
- Centro de desenvolvimento Tecnológico—CDTec, Graduate Program in biotechnology, Capão do Leão Campus, Federal de Pelotas, Pelotas 96160, Brazil; (K.E.J.d.F.); (C.B.); (J.L.L.)
| | - Rod A. Wing
- The School of Plant Sciences, Ecology & Evolutionary Biology, Arizona Genomics Institute, Tucson, AZ 97030, USA;
- Center for Desert Agriculture, King Abdullah University of Science & Technology, Thuwal 23955, Saudi Arabia
| | - Antonio Costa de Oliveira
- Centro de desenvolvimento Tecnológico—CDTec, Graduate Program in biotechnology, Capão do Leão Campus, Federal de Pelotas, Pelotas 96160, Brazil; (K.E.J.d.F.); (C.B.); (J.L.L.)
- Correspondence:
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Abbas HMK, Huang HX, Yang YF, Xie YH, Zou JF, Xue SD, Song DG, Wu TQ, Li JX, Zhong YJ. Characterization of Starch in Cucurbita moschata Germplasms throughout Fruit Development. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:9690-9696. [PMID: 32794755 DOI: 10.1021/acs.jafc.0c03181] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pumpkins (Cucurbita moschata; Cucurbitaceae) are the rich source of nutrients and valued for their biologically active substances to be used for the treatment of several diseases. The contents, composition, and conformation of starch are the significant quality traits of C. moschata. Two germplasms were targeted for analysis regarding the taste difference. Results indicated that the total starch contents and amylose/amylopectin ratio were high in CMO-X as compared to CMO-E during each fruit development stage. Scanning electron microscopy and transmission electron microscopy observations revealed that smooth surface starch granules fused together to enhance the starch accumulation. For a comparison of fruit development in CMO-E and CMO-X, the putative pathway for starch metabolism was developed and homologs were identified for each key gene involved in the pathway. GBSS and SBE were correlated with the difference in the amylose/amylopectin ratio of CMO-E and CMO-X. Conclusively, the developmental regulation of genes associated with starch accumulation can be considered as an important factor for the determination of fruit quality.
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Affiliation(s)
- Hafiz Muhammad Khalid Abbas
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - He-Xun Huang
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
| | - Yu-Fei Yang
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - Yuan-Heng Xie
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - Jian-Feng Zou
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - Shu-Dan Xue
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - Dong-Guang Song
- Department of Horticulture, College of Food Science and Engineering, Foshan University, Foshan 528000, P. R. China
| | - Ting-Quan Wu
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - Jun-Xing Li
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
| | - Yu-Juan Zhong
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China
- Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, P. R. China
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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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Wang X, Cui W, Hu W, Feng C. Abscisic acid-enhanced starch accumulation of bioenergy crop duckweed ( Spirodela polyrrhiza). RSC Adv 2020; 10:10394-10401. [PMID: 35492951 PMCID: PMC9050358 DOI: 10.1039/d0ra00269k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 02/24/2020] [Indexed: 12/03/2022] Open
Abstract
To meet the increasing energy consumption around the world and fight global climate change, there is an urgent need to explore renewable energy crops to replace the traditional energy sources. Duckweed (Spirodela polyrrhiza) is widely distributed in the world and has high starch and low lignin contents, which is perhaps an ideal feedstock for bioenergy production. To investigate the effects of abscisic acid (ABA) on duckweed biomass and starch accumulation, Spirodela polyrrhiza was cultivated at different ABA concentrations. The results showed that the highest starch content in duckweed (21.8% dry weight) was achieved in 1.0 × 10-2 mg L-1 ABA medium, 70.3% higher than that of the control medium without ABA. The number of starch granules in 1.0 × 10-2 mg L-1 ABA medium was far more than that in the control medium. The highest adenosine diphosphate (ADP)-glucose pyrophosphorylase (AGPase) activity was observed in the 1.0 × 10-2 mg L-1 ABA medium, which was caused by the up-regulation expression of ADP-glucose pyrophosphorylase 2 (APL2). Further investigations on cell ultra-structures and stomatal property of the duckweed indicated that ABA increased the number and size of starch granules and stomatal size in duckweed cells. These enhancements lead to a greatly improved energy flow in the aquatic plant from photosynthesis to carbon storage, making duckweed a potential renewable bioenergy crop.
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Affiliation(s)
- Xuezhi Wang
- School of Water Resources and Environment, China University of Geosciences (Beijing) Beijing 100083 China +86 10 82321081 +86 10 82322281
| | - Weihua Cui
- School of Water Resources and Environment, China University of Geosciences (Beijing) Beijing 100083 China +86 10 82321081 +86 10 82322281
- State Key Laboratory of Biogeology and Geology, China University of Geosciences (Beijing) Beijing 100083 China
| | - Weiwu Hu
- School of Water Resources and Environment, China University of Geosciences (Beijing) Beijing 100083 China +86 10 82321081 +86 10 82322281
- The Journal Center, China University of Geosciences (Beijing) Beijing 100083 China
| | - Chuanping Feng
- School of Water Resources and Environment, China University of Geosciences (Beijing) Beijing 100083 China +86 10 82321081 +86 10 82322281
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Braun EL. An evolutionary model motivated by physicochemical properties of amino acids reveals variation among proteins. Bioinformatics 2019; 34:i350-i356. [PMID: 29950007 PMCID: PMC6022633 DOI: 10.1093/bioinformatics/bty261] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Motivation The relative rates of amino acid interchanges over evolutionary time are likely to vary among proteins. Variation in those rates has the potential to reveal information about constraints on proteins. However, the most straightforward model that could be used to estimate relative rates of amino acid substitution is parameter-rich and it is therefore impractical to use for this purpose. Results A six-parameter model of amino acid substitution that incorporates information about the physicochemical properties of amino acids was developed. It showed that amino acid side chain volume, polarity and aromaticity have major impacts on protein evolution. It also revealed variation among proteins in the relative importance of those properties. The same general approach can be used to improve the fit of empirical models such as the commonly used PAM and LG models. Availability and implementation Perl code and test data are available from https://github.com/ebraun68/sixparam. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Edward L Braun
- Department of Biology and Genetics Institute, University of Florida, Gainesville, FL, USA
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Yu K, Liu D, Chen Y, Wang D, Yang W, Yang W, Yin L, Zhang C, Zhao S, Sun J, Liu C, Zhang A. Unraveling the genetic architecture of grain size in einkorn wheat through linkage and homology mapping and transcriptomic profiling. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4671-4688. [PMID: 31226200 PMCID: PMC6760303 DOI: 10.1093/jxb/erz247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 05/15/2019] [Indexed: 05/12/2023]
Abstract
Understanding the genetic architecture of grain size is a prerequisite to manipulating grain development and improving the potential crop yield. In this study, we conducted a whole genome-wide quantitative trait locus (QTL) mapping of grain-size-related traits by constructing a high-density genetic map using 109 recombinant inbred lines of einkorn wheat. We explored the candidate genes underlying QTLs through homologous analysis and RNA sequencing. The high-density genetic map spanned 1873 cM and contained 9937 single nucleotide polymorphism markers assigned to 1551 bins on seven chromosomes. Strong collinearity and high genome coverage of this map were revealed by comparison with physical maps of wheat and barley. Six grain size-related traits were surveyed in five environments. In total, 42 QTLs were identified; these were assigned to 17 genomic regions on six chromosomes and accounted for 52.3-66.7% of the phenotypic variation. Thirty homologous genes involved in grain development were located in 12 regions. RNA sequencing identified 4959 genes differentially expressed between the two parental lines. Twenty differentially expressed genes involved in grain size development and starch biosynthesis were mapped to nine regions that contained 26 QTLs, indicating that the starch biosynthesis pathway plays a vital role in grain development in einkorn wheat. This study provides new insights into the genetic architecture of grain size in einkorn wheat; identification of the underlying genes enables understanding of grain development and wheat genetic improvement. Furthermore, the map facilitates quantitative trait mapping, map-based cloning, genome assembly, and comparative genomics in wheat taxa.
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Affiliation(s)
- Kang Yu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Dongcheng Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Yong Chen
- Science and Technology Department, State Tobacco Monopoly Administration, Beijing, China
| | - Dongzhi Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenlong Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Wei Yang
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
| | - Lixin Yin
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
| | - Chi Zhang
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Shancen Zhao
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Jiazhu Sun
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Chunming Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Correspondence: and
| | - Aimin Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- Correspondence: and
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14
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Yu K, Liu D, Chen Y, Wang D, Yang W, Yang W, Yin L, Zhang C, Zhao S, Sun J, Liu C, Zhang A. Unraveling the genetic architecture of grain size in einkorn wheat through linkage and homology mapping and transcriptomic profiling. JOURNAL OF EXPERIMENTAL BOTANY 2019. [PMID: 31226200 DOI: 10.1101/377820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Understanding the genetic architecture of grain size is a prerequisite to manipulating grain development and improving the potential crop yield. In this study, we conducted a whole genome-wide quantitative trait locus (QTL) mapping of grain-size-related traits by constructing a high-density genetic map using 109 recombinant inbred lines of einkorn wheat. We explored the candidate genes underlying QTLs through homologous analysis and RNA sequencing. The high-density genetic map spanned 1873 cM and contained 9937 single nucleotide polymorphism markers assigned to 1551 bins on seven chromosomes. Strong collinearity and high genome coverage of this map were revealed by comparison with physical maps of wheat and barley. Six grain size-related traits were surveyed in five environments. In total, 42 QTLs were identified; these were assigned to 17 genomic regions on six chromosomes and accounted for 52.3-66.7% of the phenotypic variation. Thirty homologous genes involved in grain development were located in 12 regions. RNA sequencing identified 4959 genes differentially expressed between the two parental lines. Twenty differentially expressed genes involved in grain size development and starch biosynthesis were mapped to nine regions that contained 26 QTLs, indicating that the starch biosynthesis pathway plays a vital role in grain development in einkorn wheat. This study provides new insights into the genetic architecture of grain size in einkorn wheat; identification of the underlying genes enables understanding of grain development and wheat genetic improvement. Furthermore, the map facilitates quantitative trait mapping, map-based cloning, genome assembly, and comparative genomics in wheat taxa.
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Affiliation(s)
- Kang Yu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Dongcheng Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Yong Chen
- Science and Technology Department, State Tobacco Monopoly Administration, Beijing, China
| | - Dongzhi Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenlong Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Wei Yang
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
| | - Lixin Yin
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
| | - Chi Zhang
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Shancen Zhao
- Beijing Genomics Institute-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Jiazhu Sun
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Chunming Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Aimin Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
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15
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The Proteomic Analysis of Maize Endosperm Protein Enriched by Phos-tag tm Reveals the Phosphorylation of Brittle-2 Subunit of ADP-Glc Pyrophosphorylase in Starch Biosynthesis Process. Int J Mol Sci 2019; 20:ijms20040986. [PMID: 30813492 PMCID: PMC6412418 DOI: 10.3390/ijms20040986] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 02/14/2019] [Accepted: 02/18/2019] [Indexed: 11/17/2022] Open
Abstract
AGPase catalyzes a key rate-limiting step that converts ATP and Glc-1-p into ADP-glucose and diphosphate in maize starch biosynthesis. Previous studies suggest that AGPase is modulated by redox, thermal and allosteric regulation. However, the phosphorylation of AGPase is unclear in the kernel starch biosynthesis process. Phos-tagTM technology is a novel method using phos-tagTM agarose beads for separation, purification, and detection of phosphorylated proteins. Here we identified phos-tagTM agarose binding proteins from maize endosperm. Results showed a total of 1733 proteins identified from 10,678 distinct peptides. Interestingly, a total of 21 unique peptides for AGPase sub-unit Brittle-2 (Bt2) were identified. Bt2 was demonstrated by immunoblot when enriched maize endosperm protein with phos-tagTM agarose was in different pollination stages. In contrast, Bt2 would lose binding to phos-tagTM when samples were treated with alkaline phosphatase (ALP). Furthermore, Bt2 could be detected by Pro-Q diamond staining specifically for phosphorylated protein. We further identified the phosphorylation sites of Bt2 at Ser10, Thr451, and Thr462 by iTRAQ. In addition, dephosphorylation of Bt2 decreased the activity of AGPase in the native gel assay through ALP treatment. Taking together, these results strongly suggest that the phosphorylation of AGPase may be a new model to regulate AGPase activity in the starch biosynthesis process.
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16
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Hwang SK, Singh S, Maharana J, Kalita S, Tuncel A, Rath T, Panda D, Modi MK, Okita TW. Mechanism Underlying Heat Stability of the Rice Endosperm Cytosolic ADP-Glucose Pyrophosphorylase. FRONTIERS IN PLANT SCIENCE 2019; 10:70. [PMID: 30804963 PMCID: PMC6378277 DOI: 10.3389/fpls.2019.00070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/17/2019] [Indexed: 05/22/2023]
Abstract
Rice grains accumulate starch as their major storage reserve whose biosynthesis is sensitive to heat. ADP-glucose pyrophosphorylase (AGPase) is among the starch biosynthetic enzymes severely affected by heat stress during seed maturation. To increase the heat tolerance of the rice enzyme, we engineered two dominant AGPase subunits expressed in developing endosperm, the large (L2) and small (S2b) subunits of the cytosol-specific AGPase. Bacterial expression of the rice S2b with the rice L2, potato tuber LS (pLS), or with the mosaic rice-potato large subunits, L2-pLS and pLS-L2, produced heat-sensitive recombinant enzymes, which retained less than 10% of their enzyme activities after 5 min incubation at 55°C. However, assembly of the rice L2 with the potato tuber SS (pSS) showed significantly increased heat stability comparable to the heat-stable potato pLS/pSS. The S2b assembled with the mosaic L2-pLS subunit showed 3-fold higher sensitivity to 3-PGA than L2/S2b, whereas the counterpart mosaic pLS-L2/S2b showed 225-fold lower sensitivity. Introduction of a QTC motif into S2b created an N-terminal disulfide linkage that was cleaved by dithiothreitol reduction. The QTC enzyme showed moderate heat stability but was not as stable as the potato AGPase. While the QTC AGPase exhibited approximately fourfold increase in 3-PGA sensitivity, its substrate affinities were largely unchanged. Random mutagenesis of S2bQTC produced six mutant lines with elevated production of glycogen in bacteria. All six lines contained a L379F substitution, which conferred enhanced glycogen production in bacteria and increased heat stability. Modeled structure of this mutant enzyme revealed that this highly conserved leucine residue is located in the enzyme's regulatory pocket that provides interaction sites for activators and inhibitors. Our molecular dynamic simulation analysis suggests that introduction of the QTC motif and the L379F mutation improves enzyme heat stability by stabilizing their backbone structures possibly due to the increased number of H-bonds between the small subunits and increased intermolecular interactions between the two SSs and two LSs at elevated temperature.
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Affiliation(s)
- Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, WA, United States
| | - Salvinder Singh
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, India
| | - Jitendra Maharana
- Distributed Information Centre (DIC), Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, India
| | - Samhita Kalita
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, India
| | - Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA, United States
| | - Tanmayee Rath
- Distributed Information Centre (DIC), Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, India
| | - Debashish Panda
- Distributed Information Centre (DIC), Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, India
| | - Mahendra Kumar Modi
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, India
| | - Thomas W. Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA, United States
- *Correspondence: Thomas W. Okita,
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17
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Boehlein SK, Shaw JR, Boehlein TJ, Boehlein EC, Hannah LC. Fundamental differences in starch synthesis in the maize leaf, embryo, ovary and endosperm. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:595-606. [PMID: 30062763 DOI: 10.1111/tpj.14053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 07/23/2018] [Indexed: 05/25/2023]
Abstract
Enzymological and starch analyses of various ADP-glucose pyrophosphorylase (AGPase) null mutants point to fundamental differences in the pathways for starch synthesis in the maize leaf, embryo, ovary and endosperm. Leaf starch is synthesized via the AGPase encoded by the small and large subunits shown previously to be expressed at abundant levels in the leaf, whereas more than one AGPase isoform functions in the embryo and in the ovary. Embryo starch content is also dependent on genes functioning in the leaf and in the endosperm. AGPase encoded by shrunken-2 and brittle-2 synthesizes ~75% of endosperm starch. The gene, agpsemzm, previously shown to encode the small subunit expressed in the embryo, and agpllzm, the leaf large subunit gene, are here shown to encode the endosperm, plastid-localized AGPase. Loss of this enzyme does not reduce endosperm starch. Rather, the data suggest that AGPase-independent starch synthesis accounts for ~25% of endosperm starch. Three maize genes encode the small subunit of the AGPase. Data here show that the triple mutant lacking all three small subunits is lethal in early seed development but can be viable in both male and female gametes. Seed and plant viability is restored by any one of the three small subunit genes, including one previously thought to function only in the cytosol of the endosperm. Data herein also show the functionality of a fourth gene encoding the large subunit of this enzyme. Although adenosine diphosphate glucose pyrophosphorylase is shown here to be essential for maize viability, strong evidence for starch synthesis in the endosperm that is independent of this enzyme is also presented. Starch synthesis is distinct in the maize embryo, ovary, leaf and endosperm, and is coordinated among the various tissues.
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Affiliation(s)
- Susan K Boehlein
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Janine R Shaw
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Timothy J Boehlein
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Emily C Boehlein
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - L Curtis Hannah
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
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18
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Qu J, Xu S, Zhang Z, Chen G, Zhong Y, Liu L, Zhang R, Xue J, Guo D. Evolutionary, structural and expression analysis of core genes involved in starch synthesis. Sci Rep 2018; 8:12736. [PMID: 30143668 PMCID: PMC6109180 DOI: 10.1038/s41598-018-30411-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/30/2018] [Indexed: 01/29/2023] Open
Abstract
Starch is the main storage carbohydrate in plants and an important natural resource for food, feed and industrial raw materials. However, the details regarding the pathway for starch biosynthesis and the diversity of biosynthetic enzymes involved in this process are poorly understood. This study uses a comprehensive phylogenetic analysis of 74 sequenced plant genomes to revisit the evolutionary history of the genes encoding ADP-glucose pyrophosphorylase (AGPase), starch synthase (SS), starch branching enzyme (SBE) and starch de-branching enzyme (DBE). Additionally, the protein structures and expression patterns of these four core genes in starch biosynthesis were studied to determine their functional differences. The results showed that AGPase, SS, SBE and DBE have undergone complicated evolutionary processes in plants and that gene/genome duplications are responsible for the observed differences in isoform numbers. A structure analysis of these proteins suggested that the deletion/mutation of amino acids in some active sites resulted in not only structural variation but also sub-functionalization or neo-functionalization. Expression profiling indicated that AGPase-, SS-, SBE- and DBE-encoding genes exhibit spatio-temporally divergent expression patterns related to the composition of functional complexes in starch biosynthesis. This study provides a comprehensive atlas of the starch biosynthetic pathway, and these data should support future studies aimed at increasing understanding of starch biosynthesis and the functional evolutionary divergence of AGPase, SS, SBE, and DBE in plants.
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Affiliation(s)
- Jianzhou Qu
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Shutu Xu
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Zhengquan Zhang
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Guangzhou Chen
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Yuyue Zhong
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Linsan Liu
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Renhe Zhang
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Jiquan Xue
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China.
| | - Dongwei Guo
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China.
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Takahashi K, Ide Y, Hayakawa J, Yoshimitsu Y, Fukuhara I, Abe J, Kasai Y, Harayama S. Lipid productivity in TALEN-induced starchless mutants of the unicellular green alga Coccomyxa sp. strain Obi. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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20
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Wan H, Wu L, Yang Y, Zhou G, Ruan YL. Evolution of Sucrose Metabolism: The Dichotomy of Invertases and Beyond. TRENDS IN PLANT SCIENCE 2018; 23:163-177. [PMID: 29183781 DOI: 10.1016/j.tplants.2017.11.001] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 10/13/2017] [Accepted: 11/02/2017] [Indexed: 05/07/2023]
Abstract
In higher plants, invertases hydrolyze sucrose (Suc), the major end product of photosynthesis, into glucose (Glc) and fructose (Fru), which are used as nutrients, energy sources, and signaling molecules for plant growth, yield formation, and stress responses. The invertase enzymes, named CWINs, VINs, and CINs, are located in the cell wall, vacuole, and cytosol, respectively. We hypothesize, based on their distinctive subcellular locations and physiological roles, that invertases may have undergone different modes during evolution with important functional implications. Here, we provide phylogenetic and functional genomic evidence that CINs are evolutionarily and functionally more stable compared with CWINs and VINs, possibly reflecting their roles in maintaining cytosolic sugar homeostasis for cellular function, and that CWINs have coevolved with the vasculature, likely as a functional component of phloem unloading.
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Affiliation(s)
- Hongjian Wan
- Institute of Vegetables and State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; Australia-China Research Centre for Crop Improvement, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Limin Wu
- Australia-China Research Centre for Crop Improvement, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Yuejian Yang
- Institute of Vegetables and State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Guozhi Zhou
- Institute of Vegetables and State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yong-Ling Ruan
- Australia-China Research Centre for Crop Improvement, The University of Newcastle, Callaghan, NSW 2308, Australia; School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia.
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21
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Hou J, Li T, Wang Y, Hao C, Liu H, Zhang X. ADP-glucose pyrophosphorylase genes, associated with kernel weight, underwent selection during wheat domestication and breeding. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1533-1543. [PMID: 28371241 PMCID: PMC5698054 DOI: 10.1111/pbi.12735] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/23/2017] [Accepted: 03/26/2017] [Indexed: 05/04/2023]
Abstract
ADP-glucose pyrophosphorylase, comprising two small subunits and two large subunits, is considered a key enzyme in the endosperm starch synthesis pathway in wheat (Triticum aestivum L.). Two genes, TaAGP-S1-7A and TaAGP-L-1B, were investigated in this study. Haplotypes of these genes were associated with thousand kernel weight (TKW) in different populations. Mean TKWs of favoured haplotypes were significantly higher than those of nonfavoured ones. Two molecular markers developed to distinguish these haplotypes could be used in molecular breeding. Frequencies of favoured haplotypes were dramatically increased in cultivars released in China after the 1940s. These favoured haplotypes were also positively selected in six major wheat production regions globally. Selection of AGP-S1 and AGP-L-1B in wheat mainly occurred during and after hexaploidization. Strong additive effects of the favoured haplotypes of with other genes for starch synthesis were also detected in different populations.
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Affiliation(s)
- Jian Hou
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Tian Li
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Yamei Wang
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Chenyang Hao
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Hongxia Liu
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Xueyong Zhang
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
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22
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Batra R, Saripalli G, Mohan A, Gupta S, Gill KS, Varadwaj PK, Balyan HS, Gupta PK. Comparative Analysis of AGPase Genes and Encoded Proteins in Eight Monocots and Three Dicots with Emphasis on Wheat. FRONTIERS IN PLANT SCIENCE 2017; 8:19. [PMID: 28174576 PMCID: PMC5259687 DOI: 10.3389/fpls.2017.00019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 01/04/2017] [Indexed: 05/11/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is a heterotetrameric enzyme with two large subunits (LS) and two small subunits (SS). It plays a critical role in starch biosynthesis. We are reporting here detailed structure, function and evolution of the genes encoding the LS and the SS among monocots and dicots. "True" orthologs of maize Sh2 (AGPase LS) and Bt2 (AGPase SS) were identified in seven other monocots and three dicots; structure of the enzyme at protein level was also studied. Novel findings of the current study include the following: (i) at the DNA level, the genes controlling the SS are more conserved than those controlling the LS; the variation in both is mainly due to intron number, intron length and intron phase distribution; (ii) at protein level, the SS genes are more conserved relative to those for LS; (iii) "QTCL" motif present in SS showed evolutionary differences in AGPase belonging to wheat 7BS, T. urartu, rice and sorghum, while "LGGG" motif in LS was present in all species except T. urartu and chickpea; SS provides thermostability to AGPase, while LS is involved in regulation of AGPase activity; (iv) heterotetrameric structure of AGPase was predicted and analyzed in real time environment through molecular dynamics simulation for all the species; (v) several cis-acting regulatory elements were identified in the AGPase promoters with their possible role in regulating spatial and temporal expression (endosperm and leaf tissue) and also the expression, in response to abiotic stresses; and (vi) expression analysis revealed downregulation of both subunits under conditions of heat and drought stress. The results of the present study have allowed better understanding of structure and evolution of the genes and the encoded proteins and provided clues for exploitation of variability in these genes for engineering thermostable AGPase.
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Affiliation(s)
- Ritu Batra
- Bioinformatics Infrastructure Facility (BIF) Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India
| | - Gautam Saripalli
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India
| | - Amita Mohan
- Department of Crop and Soil Sciences, Washington State UniversityPullman, WA, USA
| | - Saurabh Gupta
- Department of Bioinformatics, Indian Institute of Information Technology-AllahabadAllahabad, India
| | - Kulvinder S. Gill
- Department of Crop and Soil Sciences, Washington State UniversityPullman, WA, USA
- *Correspondence: Kulvinder S. Gill
| | - Pritish K. Varadwaj
- Department of Bioinformatics, Indian Institute of Information Technology-AllahabadAllahabad, India
| | - Harindra S. Balyan
- Bioinformatics Infrastructure Facility (BIF) Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India
| | - Pushpendra K. Gupta
- Bioinformatics Infrastructure Facility (BIF) Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India
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23
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Jourda C, Cardi C, Gibert O, Giraldo Toro A, Ricci J, Mbéguié-A-Mbéguié D, Yahiaoui N. Lineage-Specific Evolutionary Histories and Regulation of Major Starch Metabolism Genes during Banana Ripening. FRONTIERS IN PLANT SCIENCE 2016; 7:1778. [PMID: 27994606 PMCID: PMC5133247 DOI: 10.3389/fpls.2016.01778] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/11/2016] [Indexed: 05/24/2023]
Abstract
Starch is the most widespread and abundant storage carbohydrate in plants. It is also a major feature of cultivated bananas as it accumulates to large amounts during banana fruit development before almost complete conversion to soluble sugars during ripening. Little is known about the structure of major gene families involved in banana starch metabolism and their evolution compared to other species. To identify genes involved in banana starch metabolism and investigate their evolutionary history, we analyzed six gene families playing a crucial role in plant starch biosynthesis and degradation: the ADP-glucose pyrophosphorylases (AGPases), starch synthases (SS), starch branching enzymes (SBE), debranching enzymes (DBE), α-amylases (AMY) and β-amylases (BAM). Using comparative genomics and phylogenetic approaches, these genes were classified into families and sub-families and orthology relationships with functional genes in Eudicots and in grasses were identified. In addition to known ancestral duplications shaping starch metabolism gene families, independent evolution in banana and grasses also occurred through lineage-specific whole genome duplications for specific sub-families of AGPase, SS, SBE, and BAM genes; and through gene-scale duplications for AMY genes. In particular, banana lineage duplications yielded a set of AGPase, SBE and BAM genes that were highly or specifically expressed in banana fruits. Gene expression analysis highlighted a complex transcriptional reprogramming of starch metabolism genes during ripening of banana fruits. A differential regulation of expression between banana gene duplicates was identified for SBE and BAM genes, suggesting that part of starch metabolism regulation in the fruit evolved in the banana lineage.
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Affiliation(s)
- Cyril Jourda
- CIRAD, UMR AGAPMontpellier, France
- CIRAD, UMR PVBMTSaint-Pierre, France
| | | | - Olivier Gibert
- CIRAD, UMR QUALISUDMontpellier, France
- CIRAD, UMR QUALISUDJakarta, Indonesia
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24
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Campbell BC, Gilding EK, Mace ES, Tai S, Tao Y, Prentis PJ, Thomelin P, Jordan DR, Godwin ID. Domestication and the storage starch biosynthesis pathway: signatures of selection from a whole sorghum genome sequencing strategy. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:2240-2253. [PMID: 27155090 PMCID: PMC5103234 DOI: 10.1111/pbi.12578] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/02/2016] [Indexed: 05/04/2023]
Abstract
Next-generation sequencing of complete genomes has given researchers unprecedented levels of information to study the multifaceted evolutionary changes that have shaped elite plant germplasm. In conjunction with population genetic analytical techniques and detailed online databases, we can more accurately capture the effects of domestication on entire biological pathways of agronomic importance. In this study, we explore the genetic diversity and signatures of selection in all predicted gene models of the storage starch synthesis pathway of Sorghum bicolor, utilizing a diversity panel containing lines categorized as either 'Landraces' or 'Wild and Weedy' genotypes. Amongst a total of 114 genes involved in starch synthesis, 71 had at least a single signal of purifying selection and 62 a signal of balancing selection and others a mix of both. This included key genes such as STARCH PHOSPHORYLASE 2 (SbPHO2, under balancing selection), PULLULANASE (SbPUL, under balancing selection) and ADP-glucose pyrophosphorylases (SHRUNKEN2, SbSH2 under purifying selection). Effectively, many genes within the primary starch synthesis pathway had a clear reduction in nucleotide diversity between the Landraces and wild and weedy lines indicating that the ancestral effects of domestication are still clearly identifiable. There was evidence of the positional rate variation within the well-characterized primary starch synthesis pathway of sorghum, particularly in the Landraces, whereby low evolutionary rates upstream and high rates downstream in the metabolic pathway were expected. This observation did not extend to the wild and weedy lines or the minor starch synthesis pathways.
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Affiliation(s)
- Bradley C. Campbell
- School of Agriculture and Food SciencesThe University of QueenslandBrisbaneQldAustralia
| | - Edward K. Gilding
- School of Agriculture and Food SciencesThe University of QueenslandBrisbaneQldAustralia
| | - Emma S. Mace
- Department of Agriculture and Fisheries (DAF)WarwickQldAustralia
| | | | - Yongfu Tao
- Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandWarwickQldAustralia
| | - Peter J. Prentis
- Science and Engineering FacultyQueensland University of Technology (QUT)BrisbaneQldAustralia
| | - Pauline Thomelin
- Australian Centre for Plant Functional GenomicsGlen OsmondSAAustralia
| | - David R. Jordan
- Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandWarwickQldAustralia
| | - Ian D. Godwin
- School of Agriculture and Food SciencesThe University of QueenslandBrisbaneQldAustralia
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25
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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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26
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Tang XJ, Peng C, Zhang J, Cai Y, You XM, Kong F, Yan HG, Wang GX, Wang L, Jin J, Chen WW, Chen XG, Ma J, Wang P, Jiang L, Zhang WW, Wan JM. ADP-glucose pyrophosphorylase large subunit 2 is essential for storage substance accumulation and subunit interactions in rice endosperm. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 249:70-83. [PMID: 27297991 DOI: 10.1016/j.plantsci.2016.05.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/04/2016] [Accepted: 05/13/2016] [Indexed: 05/26/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) controls a rate-limiting step in the starch biosynthetic pathway in higher plants. Here we isolated a shrunken rice mutant w24. Map-based cloning identified OsAGPL2, a large subunit of the cytosolic AGPase in rice endosperm, as the gene responsible for the w24 mutation. In addition to severe inhibition of starch synthesis and significant accumulation of sugar, the w24 endosperm showed obvious defects in compound granule formation and storage protein synthesis. The defect in OsAGPL2 enhanced the expression levels of the AGPase family. Meanwhile, the elevated activities of starch phosphorylase 1 and sucrose synthase in the w24 endosperm might possibly partly account for the residual starch content in the mutant seeds. Moreover, the expression of OsAGPL2 and its counterpart, OsAGPS2b, was highly coordinated in rice endosperm. Yeast two-hybrid and BiFC assays verified direct interactions between OsAGPL2 and OsAGPS2b as well as OsAGPL1 and OsAGPS1, supporting the model for spatiotemporal complex formation of AGPase isoforms in rice endosperm. Besides, our data provided no evidence for the self-binding of OsAGPS2b, implying that OsAGPS2b might not interact to form higher molecular mass aggregates in the absence of OsAGPL2. Therefore, the molecular mechanism of rice AGPase assembly might differ from that of Arabidopsis.
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Affiliation(s)
- Xiao-Jie Tang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Cheng Peng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Jie Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Yue Cai
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Xiao-Man You
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Fei Kong
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Hai-Gang Yan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Guo-Xiang Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Liang Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Jie Jin
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Wei-Wei Chen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Xin-Gang Chen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Jing Ma
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Peng Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China
| | - Wen-Wei Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China.
| | - Jian-Min Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 1 Weigang Road, Nanjing 210095, China; Institute of Crop Science, The National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, China.
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27
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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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28
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Saripalli G, Gupta PK. AGPase: its role in crop productivity with emphasis on heat tolerance in cereals. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2015; 128:1893-916. [PMID: 26152573 DOI: 10.1007/s00122-015-2565-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/16/2015] [Indexed: 05/11/2023]
Abstract
AGPase, a key enzyme of starch biosynthetic pathway, has a significant role in crop productivity. Thermotolerant variants of AGPase in cereals may be used for developing cultivars, which may enhance productivity under heat stress. Improvement of crop productivity has always been the major goal of plant breeders to meet the global demand for food. However, crop productivity itself is influenced in a large measure by a number of abiotic stresses including heat, which causes major losses in crop productivity. In cereals, crop productivity in terms of grain yield mainly depends upon the seed starch content so that starch biosynthesis and the enzymes involved in this process have been a major area of investigation for plant physiologists and plant breeders alike. Considerable work has been done on AGPase and its role in crop productivity, particularly under heat stress, because this enzyme is one of the major enzymes, which catalyses the rate-limiting first committed key enzymatic step of starch biosynthesis. Keeping the above in view, this review focuses on the basic features of AGPase including its structure, regulatory mechanisms involving allosteric regulators, its sub-cellular localization and its genetics. Major emphasis, however, has been laid on the genetics of AGPases and its manipulation for developing high yielding cultivars that will have comparable productivity under heat stress. Some important thermotolerant variants of AGPase, which mainly involve specific amino acid substitutions, have been highlighted, and the prospects of using these thermotolerant variants of AGPase in developing cultivars for heat prone areas have been discussed. The review also includes a brief account on transgenics for AGPase, which have been developed for basic studies and crop improvement.
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Affiliation(s)
- Gautam Saripalli
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch.Charan Singh University, Meerut, 250004, India
| | - Pushpendra Kumar Gupta
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch.Charan Singh University, Meerut, 250004, India.
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29
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Saripalli G, Gupta PK. AGPase: its role in crop productivity with emphasis on heat tolerance in cereals. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2015. [PMID: 26152573 DOI: 10.1007/s00122-015-2565-2562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
AGPase, a key enzyme of starch biosynthetic pathway, has a significant role in crop productivity. Thermotolerant variants of AGPase in cereals may be used for developing cultivars, which may enhance productivity under heat stress. Improvement of crop productivity has always been the major goal of plant breeders to meet the global demand for food. However, crop productivity itself is influenced in a large measure by a number of abiotic stresses including heat, which causes major losses in crop productivity. In cereals, crop productivity in terms of grain yield mainly depends upon the seed starch content so that starch biosynthesis and the enzymes involved in this process have been a major area of investigation for plant physiologists and plant breeders alike. Considerable work has been done on AGPase and its role in crop productivity, particularly under heat stress, because this enzyme is one of the major enzymes, which catalyses the rate-limiting first committed key enzymatic step of starch biosynthesis. Keeping the above in view, this review focuses on the basic features of AGPase including its structure, regulatory mechanisms involving allosteric regulators, its sub-cellular localization and its genetics. Major emphasis, however, has been laid on the genetics of AGPases and its manipulation for developing high yielding cultivars that will have comparable productivity under heat stress. Some important thermotolerant variants of AGPase, which mainly involve specific amino acid substitutions, have been highlighted, and the prospects of using these thermotolerant variants of AGPase in developing cultivars for heat prone areas have been discussed. The review also includes a brief account on transgenics for AGPase, which have been developed for basic studies and crop improvement.
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Affiliation(s)
- Gautam Saripalli
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch.Charan Singh University, Meerut, 250004, India
| | - Pushpendra Kumar Gupta
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch.Charan Singh University, Meerut, 250004, India.
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30
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Saripalli G, Gupta PK. AGPase: its role in crop productivity with emphasis on heat tolerance in cereals. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2015; 128:1893-1916. [PMID: 26152573 DOI: 10.1007/s00122-015-25652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/16/2015] [Indexed: 05/26/2023]
Abstract
AGPase, a key enzyme of starch biosynthetic pathway, has a significant role in crop productivity. Thermotolerant variants of AGPase in cereals may be used for developing cultivars, which may enhance productivity under heat stress. Improvement of crop productivity has always been the major goal of plant breeders to meet the global demand for food. However, crop productivity itself is influenced in a large measure by a number of abiotic stresses including heat, which causes major losses in crop productivity. In cereals, crop productivity in terms of grain yield mainly depends upon the seed starch content so that starch biosynthesis and the enzymes involved in this process have been a major area of investigation for plant physiologists and plant breeders alike. Considerable work has been done on AGPase and its role in crop productivity, particularly under heat stress, because this enzyme is one of the major enzymes, which catalyses the rate-limiting first committed key enzymatic step of starch biosynthesis. Keeping the above in view, this review focuses on the basic features of AGPase including its structure, regulatory mechanisms involving allosteric regulators, its sub-cellular localization and its genetics. Major emphasis, however, has been laid on the genetics of AGPases and its manipulation for developing high yielding cultivars that will have comparable productivity under heat stress. Some important thermotolerant variants of AGPase, which mainly involve specific amino acid substitutions, have been highlighted, and the prospects of using these thermotolerant variants of AGPase in developing cultivars for heat prone areas have been discussed. The review also includes a brief account on transgenics for AGPase, which have been developed for basic studies and crop improvement.
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Affiliation(s)
- Gautam Saripalli
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch.Charan Singh University, Meerut, 250004, India
| | - Pushpendra Kumar Gupta
- Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch.Charan Singh University, Meerut, 250004, India.
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31
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Schwarte S, Wegner F, Havenstein K, Groth D, Steup M, Tiedemann R. Sequence variation, differential expression, and divergent evolution in starch-related genes among accessions of Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2015; 87:489-519. [PMID: 25663508 DOI: 10.1007/s11103-015-0293-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 01/26/2015] [Indexed: 06/04/2023]
Abstract
Transitory starch metabolism is a nonlinear and highly regulated process. It originated very early in the evolution of chloroplast-containing cells and is largely based on a mosaic of genes derived from either the eukaryotic host cell or the prokaryotic endosymbiont. Initially located in the cytoplasm, starch metabolism was rewired into plastids in Chloroplastida. Relocation was accompanied by gene duplications that occurred in most starch-related gene families and resulted in subfunctionalization of the respective gene products. Starch-related isozymes were then evolutionary conserved by constraints such as internal starch structure, posttranslational protein import into plastids and interactions with other starch-related proteins. 25 starch-related genes in 26 accessions of Arabidopsis thaliana were sequenced to assess intraspecific diversity, phylogenetic relationships, and modes of selection. Furthermore, sequences derived from additional 80 accessions that are publicly available were analyzed. Diversity varies significantly among the starch-related genes. Starch synthases and phosphorylases exhibit highest nucleotide diversities, while pyrophosphatases and debranching enzymes are most conserved. The gene trees are most compatible with a scenario of extensive recombination, perhaps in a Pleistocene refugium. Most genes are under purifying selection, but disruptive selection was inferred for a few genes/substitutiones. To study transcript levels, leaves were harvested throughout the light period. By quantifying the transcript levels and by analyzing the sequence of the respective accessions, we were able to estimate whether transcript levels are mainly determined by genetic (i.e., accession dependent) or physiological (i.e., time dependent) parameters. We also identified polymorphic sites that putatively affect pattern or the level of transcripts.
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Affiliation(s)
- Sandra Schwarte
- Evolutionary Biology, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, Building 26, 14476, Potsdam, Germany,
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32
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Tuncel A, Cakir B, Hwang SK, Okita TW. The role of the large subunit in redox regulation of the rice endosperm ADP-glucose pyrophosphorylase. FEBS J 2014; 281:4951-63. [PMID: 25204204 DOI: 10.1111/febs.13041] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/08/2014] [Accepted: 09/04/2014] [Indexed: 01/31/2023]
Abstract
The starch regulatory enzyme ADP-glucose pyrophosphorylase is activated by 3-phosphoglyceric acid (3-PGA) and inhibited by inorganic phosphate (Pi ). The activity of the plastid-localized enzyme is also subject to fine regulation by redox control in response to changing light and sugar levels. The less active oxidized form of the enzyme contains an inter-subunit disulfide bond formed between the pair of small subunit's Cys12 residues of the heterotetrameric enzyme. Although this cysteine residue is not conserved in the small subunits of cereal endosperm cytosolic AGPases, biochemical studies of the major rice endosperm enzyme indicate that the cytosolic isoform, like the plastidial enzymes, is subject to redox control. Kinetic analysis revealed that the reduced forms of the partially purified native and purified recombinant AGPases have 6- and 3.4-fold, respectively, more affinity to 3-PGA, rendering the enzymes more active at lower 3-PGA concentration than the non-reduced enzyme. Truncation of the large subunit by removal of N-terminal peptide resulted in a decrease in 3-PGA affinity and loss of redox response of the enzyme. Site-directed mutagenesis of the conserved cysteine residues at the N-terminal of the large subunit showed that C47 and C58, but not C12, are essential for proper redox response of the enzyme. Overall, our results show that the major rice endosperm AGPase activity is controlled by a combination of allosteric regulation and redox control, the latter through modification of the large subunit instead of the small subunit as evident in the plastid-localized enzyme.
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Affiliation(s)
- Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
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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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Mahendhiran M, Ramirez-Prado JH, Escobedo-Gracia Medrano RM, Canto-Canché B, Tzec-Simá M, Grijalva-Arango R, James-Kay A. Single nucleotide polymorphisms in partial sequences of the gene encoding the large sub-units of ADP-glucose pyrophosphorylase within a representative collection of 10 Musa genotypes. ELECTRON J BIOTECHN 2014. [DOI: 10.1016/j.ejbt.2014.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Boehlein SK, Shaw JR, Georgelis N, Hannah LC. Enhanced heat stability and kinetic parameters of maize endosperm ADPglucose pyrophosphorylase by alteration of phylogenetically identified amino acids. Arch Biochem Biophys 2013; 543:1-9. [PMID: 24378757 DOI: 10.1016/j.abb.2013.12.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 12/12/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Abstract
ADP-glucose pyrophosphorylase (AGPase) controls the rate-limiting step in starch biosynthesis and is regulated at various levels. Cereal endosperm enzymes, in contrast to other plant AGPases, are particularly heat labile and transgenic studies highlight the importance of temperature for cereal yield. Previously, a phylogenetic approach identified Type II and positively selected amino acid positions in the large subunit of maize endosperm AGPase. Glycogen content, kinetic parameters and heat stability were measured in AGPases having mutations in these sites and interesting differences were observed. This study expands on our earlier evolutionary work by determining how all Type II and positively selected sites affect kinetic constants, heat stability and catalytic rates at increased temperatures. Variants with enhanced properties were identified and combined into one gene, designated Sh2-E. Enhanced properties include: heat stability, enhanced activity at 37 °C, activity at 55 °C, reduced Ka and activity in the absence of activator. The resulting enzyme exhibited all improved properties of the various individual changes. Additionally, Sh2-E was expressed with a small subunit variant with enhanced enzyme properties resulting in an enzyme that has exceptional heat stability, a high catalytic rate at increased temperatures and significantly decreased Km values for both substrates in the absence of the activator.
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Affiliation(s)
- Susan K Boehlein
- 1253 Fifield Hall, University of Florida, Gainesville, FL 32611, USA
| | - Janine R Shaw
- 1253 Fifield Hall, University of Florida, Gainesville, FL 32611, USA
| | | | - L Curtis Hannah
- 1253 Fifield Hall, University of Florida, Gainesville, FL 32611, USA.
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Hannah LC, Futch B, Bing J, Shaw JR, Boehlein S, Stewart JD, Beiriger R, Georgelis N, Greene T. A shrunken-2 transgene increases maize yield by acting in maternal tissues to increase the frequency of seed development. THE PLANT CELL 2012; 24:2352-63. [PMID: 22751213 PMCID: PMC3406911 DOI: 10.1105/tpc.112.100602] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 05/17/2012] [Accepted: 06/15/2012] [Indexed: 05/19/2023]
Abstract
The maize (Zea mays) shrunken-2 (Sh2) gene encodes the large subunit of the rate-limiting starch biosynthetic enzyme, ADP-glucose pyrophosphorylase. Expression of a transgenic form of the enzyme with enhanced heat stability and reduced phosphate inhibition increased maize yield up to 64%. The extent of the yield increase is dependent on temperatures during the first 4 d post pollination, and yield is increased if average daily high temperatures exceed 33 °C. As found in wheat (Triticum aestivum) and rice (Oryza sativa), this transgene increases maize yield by increasing seed number. This result was surprising, since an entire series of historic observations at the whole-plant, enzyme, gene, and physiological levels pointed to Sh2 playing an important role only in the endosperm. Here, we present several lines of evidence that lead to the conclusion that the Sh2 transgene functions in maternal tissue to increase seed number and, in turn, yield. Furthermore, the transgene does not increase ovary number; rather, it increases the probability that a seed will develop. Surprisingly, the number of fully developed seeds is only ∼50% of the number of ovaries in wild-type maize. This suggests that increasing the frequency of seed development is a feasible agricultural target, especially under conditions of elevated temperatures.
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Affiliation(s)
- L Curtis Hannah
- Department of Horticultural Sciences, University of Florida, Gainesville, Florida 32611, USA.
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Li C, Li QG, Dunwell JM, Zhang YM. Divergent evolutionary pattern of starch biosynthetic pathway genes in grasses and dicots. Mol Biol Evol 2012; 29:3227-36. [PMID: 22586327 DOI: 10.1093/molbev/mss131] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Starch is the most widespread and abundant storage carbohydrate in crops and its production is critical to both crop yield and quality. In regard to the starch content in the seeds of crop plants, there is a distinct difference between grasses (Poaceae) and dicots. However, few studies have described the evolutionary pattern of genes in the starch biosynthetic pathway in these two groups of plants. In this study, therefore, an attempt was made to compare evolutionary rate, gene duplication, and selective pattern of the key genes involved in this pathway between the two groups, using five grasses and five dicots as materials. The results showed 1) distinct differences in patterns of gene duplication and loss between grasses and dicots; duplication in grasses mainly occurred before the divergence of grasses, whereas duplication mostly occurred in individual species within the dicots; there is less gene loss in grasses than in dicots, 2) a considerably higher evolutionary rate in grasses than in dicots in most gene families analyzed, and 3) evidence of a different selective pattern between grasses and dicots; positive selection may have occurred asymmetrically in grasses in some gene families, for example, ADP-glucose pyrophosphorylase small subunit. Therefore, we deduced that gene duplication contributes to, and a higher evolutionary rate is associated with, the higher starch content in grasses. In addition, two novel aspects of the evolution of the starch biosynthetic pathway were observed.
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Affiliation(s)
- Chun Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Agriculture, Department of Crop Genetics and Breeding, Nanjing Agricultural University, Nanjing, People's Republic of China
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Corbi J, Dutheil JY, Damerval C, Tenaillon MI, Manicacci D. Accelerated evolution and coevolution drove the evolutionary history of AGPase sub-units during angiosperm radiation. ANNALS OF BOTANY 2012; 109:693-708. [PMID: 22307567 PMCID: PMC3286274 DOI: 10.1093/aob/mcr303] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/07/2011] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS ADP-glucose pyrophosphorylase (AGPase) is a key enzyme of starch biosynthesis. In the green plant lineage, it is composed of two large (LSU) and two small (SSU) sub-units encoded by paralogous genes, as a consequence of several rounds of duplication. First, our aim was to detect specific patterns of molecular evolution following duplication events and the divergence between monocotyledons and dicotyledons. Secondly, we investigated coevolution between amino acids both within and between sub-units. METHODS A phylogeny of each AGPase sub-unit was built using all gymnosperm and angiosperm sequences available in databases. Accelerated evolution along specific branches was tested using the ratio of the non-synonymous to the synonymous substitution rate. Coevolution between amino acids was investigated taking into account compensatory changes between co-substitutions. KEY RESULTS We showed that SSU paralogues evolved under high functional constraints during angiosperm radiation, with a significant level of coevolution between amino acids that participate in SSU major functions. In contrast, in the LSU paralogues, we identified residues under positive selection (1) following the first LSU duplication that gave rise to two paralogues mainly expressed in angiosperm source and sink tissues, respectively; and (2) following the emergence of grass-specific paralogues expressed in the endosperm. Finally, we found coevolution between residues that belong to the interaction domains of both sub-units. CONCLUSIONS Our results support the view that coevolution among amino acid residues, especially those lying in the interaction domain of each sub-unit, played an important role in AGPase evolution. First, within SSU, coevolution allowed compensating mutations in a highly constrained context. Secondly, the LSU paralogues probably acquired tissue-specific expression and regulatory properties via the coevolution between sub-unit interacting domains. Finally, the pattern we observed during LSU evolution is consistent with repeated sub-functionalization under 'Escape from Adaptive Conflict', a model rarely illustrated in the literature.
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Affiliation(s)
- Jonathan Corbi
- CNRS, UMR 0320/UMR 8120 Génétique Végétale, Ferme du Moulon, F-91190 Gif sur Yvette, France
| | - Julien Y. Dutheil
- BiRC-Bioinformatics Research Center, Aarhus University, C.F. Møllers Alle 8, Building 1110, DK-8000 Århus C, Denmark
| | - Catherine Damerval
- CNRS, UMR 0320/UMR 8120 Génétique Végétale, Ferme du Moulon, F-91190 Gif sur Yvette, France
| | - Maud I. Tenaillon
- CNRS, UMR 0320/UMR 8120 Génétique Végétale, Ferme du Moulon, F-91190 Gif sur Yvette, France
| | - Domenica Manicacci
- Université Paris-Sud, UMR 0320/UMR 8120 Génétique Végétale, Ferme du Moulon, F-91190 Gif sur Yvette, France
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Wang W, Messing J. Analysis of ADP-glucose pyrophosphorylase expression during turion formation induced by abscisic acid in Spirodela polyrhiza (greater duckweed). BMC PLANT BIOLOGY 2012; 12:5. [PMID: 22235974 PMCID: PMC3268088 DOI: 10.1186/1471-2229-12-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 01/11/2012] [Indexed: 05/10/2023]
Abstract
BACKGROUND Aquatic plants differ in their development from terrestrial plants in their morphology and physiology, but little is known about the molecular basis of the major phases of their life cycle. Interestingly, in place of seeds of terrestrial plants their dormant phase is represented by turions, which circumvents sexual reproduction. However, like seeds turions provide energy storage for starting the next growing season. RESULTS To begin a characterization of the transition from the growth to the dormant phase we used abscisic acid (ABA), a plant hormone, to induce controlled turion formation in Spirodela polyrhiza and investigated their differentiation from fronds, representing their growth phase, into turions with respect to morphological, ultra-structural characteristics, and starch content. Turions were rich in anthocyanin pigmentation and had a density that submerged them to the bottom of liquid medium. Transmission electron microscopy (TEM) of turions showed in comparison to fronds shrunken vacuoles, smaller intercellular space, and abundant starch granules surrounded by thylakoid membranes. Turions accumulated more than 60% starch in dry mass after two weeks of ABA treatment. To further understand the mechanism of the developmental switch from fronds to turions, we cloned and sequenced the genes of three large-subunit ADP-glucose pyrophosphorylases (APLs). All three putative protein and exon sequences were conserved, but the corresponding genomic sequences were extremely variable mainly due to the invasion of miniature inverted-repeat transposable elements (MITEs) into introns. A molecular three-dimensional model of the SpAPLs was consistent with their regulatory mechanism in the interaction with the substrate (ATP) and allosteric activator (3-PGA) to permit conformational changes of its structure. Gene expression analysis revealed that each gene was associated with distinct temporal expression during turion formation. APL2 and APL3 were highly expressed in earlier stages of turion development, while APL1 expression was reduced throughout turion development. CONCLUSIONS These results suggest that the differential expression of APLs could be used to enhance energy flow from photosynthesis to storage of carbon in aquatic plants, making duckweeds a useful alternative biofuel feedstock.
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Affiliation(s)
- Wenqin Wang
- Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA
- Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ 08901, USA
| | - Joachim Messing
- Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA
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Corbi J, Debieu M, Rousselet A, Montalent P, Le Guilloux M, Manicacci D, Tenaillon MI. Contrasted patterns of selection since maize domestication on duplicated genes encoding a starch pathway enzyme. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2011; 122:705-22. [PMID: 21060986 DOI: 10.1007/s00122-010-1480-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 10/22/2010] [Indexed: 05/08/2023]
Abstract
Maize domestication from teosinte (Zea mays ssp. parviglumis) was accompanied by an increase of kernel size in landraces. Subsequent breeding has led to a diversification of kernel size and starch content among major groups of inbred lines. We aim at investigating the effect of domestication on duplicated genes encoding a key enzyme of the starch pathway, the ADP-glucose pyrophosphorylase (AGPase). Three pairs of paralogs encode the AGPase small (SSU) and large (LSU) subunits mainly expressed in the endosperm, the embryo and the leaf. We first validated the putative sequence of LSU(leaf) through a comparative expression assay of the six genes. Second, we investigated the patterns of molecular evolution on a 2 kb coding region homologous among the six genes in three panels: teosintes, landraces, and inbred lines. We corrected for demographic effects by relying on empirical distributions built from 580 previously sequenced ESTs. We found contrasted patterns of selection among duplicates: three genes exhibit patterns of directional selection during domestication (SSU(end), LSU(emb)) or breeding (LSU(leaf)), two exhibit patterns consistent with diversifying (SSU(leaf)) and balancing selection (SSU(emb)) accompanying maize breeding. While patterns of linkage disequilibrium did not reveal sign of coevolution between genes expressed in the same organ, we detected an excess of non-synonymous substitutions in the small subunit functional domains highlighting their role in AGPase evolution. Our results offer a different picture on AGPase evolution than the one depicted at the Angiosperm level and reveal how genetic redundancy can provide flexibility in the response to selection.
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Affiliation(s)
- J Corbi
- CNRS, UMR 0320/UMR 8120 Génétique Végétale, Ferme du Moulon, Gif sur Yvette, France
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Boehlein SK, Shaw JR, Hannah LC, Stewart JD. Probing allosteric binding sites of the maize endosperm ADP-glucose pyrophosphorylase. PLANT PHYSIOLOGY 2010; 152:85-95. [PMID: 19889875 PMCID: PMC2799348 DOI: 10.1104/pp.109.146928] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Maize (Zea mays) endosperm ADP-glucose pyrophosphorylase (AGPase) is a highly regulated enzyme that catalyzes the rate-limiting step in starch biosynthesis. Although the structure of the heterotetrameric maize endosperm AGPase remains unsolved, structures of a nonnative, low-activity form of the potato tuber (Solanum tuberosum) AGPase (small subunit homotetramer) reported previously by others revealed that several sulfate ions bind to each enzyme. These sites are also believed to interact with allosteric regulators such as inorganic phosphate and 3-phosphoglycerate (3-PGA). Several arginine (Arg) side chains contact the bound sulfate ions in the potato structure and likely play important roles in allosteric effector binding. Alanine-scanning mutagenesis was applied to the corresponding Arg residues in both the small and large subunits of maize endosperm AGPase to determine their roles in allosteric regulation and thermal stability. Steady-state kinetic and regulatory parameters were measured for each mutant. All of the Arg mutants examined--in both the small and large subunits--bound 3-PGA more weakly than the wild type (A(50) increased by 3.5- to 20-fold). By contrast, the binding of two other maize AGPase allosteric activators (fructose-6-phosphate and glucose-6-phosphate) did not always mimic the changes observed for 3-PGA. In fact, compared to 3-PGA, fructose-6-phosphate is a more efficient activator in two of the Arg mutants. Phosphate binding was also affected by Arg substitutions. The combined data support a model for the binding interactions associated with 3-PGA in which allosteric activators and inorganic phosphate compete directly.
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In planta mutagenesis determines the functional regions of the wheat puroindoline proteins. Genetics 2009; 183:853-60. [PMID: 19752217 DOI: 10.1534/genetics.109.106013] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In planta analysis of protein function in a crop plant could lead to improvements in understanding protein structure/function relationships as well as selective agronomic or end product quality improvements. The requirements for successful in planta analysis are a high mutation rate, an efficient screening method, and a trait with high heritability. Two ideal targets for functional analysis are the Puroindoline a and Puroindoline b (Pina and Pinb, respectively) genes, which together compose the wheat (Triticum aestivum L.) Ha locus that controls grain texture and many wheat end-use properties. Puroindolines (PINs) together impart soft texture, and mutations in either PIN result in hard seed texture. Studies of the PINs' mode of action are limited by low allelic variation. To create new Pin alleles and identify critical function-determining regions, Pin point mutations were created in planta via EMS treatment of a soft wheat. Grain hardness of 46 unique PIN missense alleles was then measured using segregating F(2):F(3) populations. The impact of individual missense alleles upon PIN function, as measured by grain hardness, ranged from neutral (74%) to intermediate to function abolishing. The percentage of function-abolishing mutations among mutations occurring in both PINA and PINB was higher for PINB, indicating that PINB is more critical to overall Ha function. This is contrary to expectations in that PINB is not as well conserved as PINA. All function-abolishing mutations resulted from structure-disrupting mutations or from missense mutations occurring near the Tryptophan-rich region. This study demonstrates the feasibility of in planta functional analysis of wheat proteins and that the Tryptophan-rich region is the most important region of both PINA and PINB.
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Georgelis N, Shaw JR, Hannah LC. Phylogenetic analysis of ADP-glucose pyrophosphorylase subunits reveals a role of subunit interfaces in the allosteric properties of the enzyme. PLANT PHYSIOLOGY 2009; 151:67-77. [PMID: 19625637 PMCID: PMC2735977 DOI: 10.1104/pp.109.138933] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) catalyzes a rate-limiting step in glycogen and starch synthesis in bacteria and plants, respectively. Plant AGPase consists of two large and two small subunits that were derived by gene duplication. AGPase large subunits have functionally diverged, leading to different kinetic and allosteric properties. Amino acid changes that could account for these differences were identified previously by evolutionary analysis. In this study, these large subunit residues were mapped onto a modeled structure of the maize (Zea mays) endosperm enzyme. Surprisingly, of 29 amino acids identified via evolutionary considerations, 17 were located at subunit interfaces. Fourteen of the 29 amino acids were mutagenized in the maize endosperm large subunit (SHRUNKEN-2 [SH2]), and resulting variants were expressed in Escherichia coli with the maize endosperm small subunit (BT2). Comparisons of the amount of glycogen produced in E. coli, and the kinetic and allosteric properties of the variants with wild-type SH2/BT2, indicate that 11 variants differ from the wild type in enzyme properties or in vivo glycogen level. More interestingly, six of nine residues located at subunit interfaces exhibit altered allosteric properties. These results indicate that the interfaces between the large and small subunits are important for the allosteric properties of AGPase, and changes at these interfaces contribute to AGPase functional specialization. Our results also demonstrate that evolutionary analysis can greatly facilitate enzyme structure-function analyses.
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Affiliation(s)
- Nikolaos Georgelis
- Program in Plant Molecular and Cellular Biology and Horticultural Sciences, University of Florida, Gainesville, Florida 32610-0245, USA
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Li J, Francisco P, Zhou W, Edner C, Steup M, Ritte G, Bond CS, Smith SM. Catalytically-inactive beta-amylase BAM4 required for starch breakdown in Arabidopsis leaves is a starch-binding-protein. Arch Biochem Biophys 2009; 489:92-8. [PMID: 19664588 DOI: 10.1016/j.abb.2009.07.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/23/2009] [Accepted: 07/31/2009] [Indexed: 12/15/2022]
Abstract
Of the four chloroplast beta-amylase (BAM) proteins identified in Arabidopsis, BAM3 and BAM4 were previously shown to play the major roles in leaf starch breakdown, although BAM4 apparently lacks key active site residues and beta-amylase activity. Here we tested multiple BAM4 proteins with different N-terminal sequences with a range of glucan substrates and assay methods, but detected no alpha-1,4-glucan hydrolase activity. BAM4 did not affect BAM1, BAM2 or BAM3 activity even when added in 10-fold excess, nor the BAM3-catalysed release of maltose from isolated starch granules in the presence of glucan water dikinase. However, BAM4 binds to amylopectin and to amylose-Sepharose whereas BAM2 has very low beta-amylase activity and poor glucan binding. The low activity of BAM2 may be explained by poor glucan binding but absence of BAM4 activity is not. These results suggest that BAM4 facilitates starch breakdown by a mechanism involving direct interaction with starch or other alpha-1,4-glucan.
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Affiliation(s)
- Jing Li
- Centres of Excellence for Plant Metabolomics, Plant Energy Biology, Crawley, WA 6009, Australia
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Boehlein SK, Shaw JR, Stewart JD, Hannah LC. Characterization of an autonomously activated plant ADP-glucose pyrophosphorylase. PLANT PHYSIOLOGY 2009; 149:318-26. [PMID: 18715954 PMCID: PMC2613723 DOI: 10.1104/pp.108.126862] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Accepted: 08/08/2008] [Indexed: 05/23/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) catalyzes the rate-limiting step in starch biosynthesis in plants and changes in its catalytic and/or allosteric properties can lead to increased starch production. Recently, a maize (Zea mays)/potato (Solanum tuberosum) small subunit mosaic, MP [Mos(1-198)], containing the first 198 amino acids of the small subunit of the maize endosperm enzyme and the last 277 amino acids from the potato tuber enzyme, was expressed with the maize endosperm large subunit and was reported to have favorable kinetic and allosteric properties. Here, we show that this mosaic, in the absence of activator, performs like a wild-type AGPase that is partially activated with 3-phosphoglyceric acid (3-PGA). In the presence of 3-PGA, enzyme properties of Mos(1-198)/SH2 are quite similar to those of the wild-type maize enzyme. In the absence of 3-PGA, however, the mosaic enzyme exhibits greater activity, higher affinity for the substrates, and partial inactivation by inorganic phosphate. The Mos(1-198)/SH2 enzyme is also more stable to heat inactivation. The different properties of this protein were mapped using various mosaics containing smaller portions of the potato small subunit. Enhanced heat stability of Mos(1-198) was shown to originate from five potato-derived amino acids between 322 and 377. These amino acids were shown previously to be important in small subunit/large subunit interactions. These five potato-derived amino acids plus other potato-derived amino acids distributed throughout the carboxyl-terminal portion of the protein are required for the enhanced catalytic and allosteric properties exhibited by Mos(1-198)/SH2.
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Affiliation(s)
- Susan K Boehlein
- Program in Plant Molecular and Cellular Biology and Horticultural Sciences, University of Florida, Gainesville, Florida 32611-7200, USA
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Ventriglia T, Kuhn ML, Ruiz MT, Ribeiro-Pedro M, Valverde F, Ballicora MA, Preiss J, Romero JM. Two Arabidopsis ADP-glucose pyrophosphorylase large subunits (APL1 and APL2) are catalytic. PLANT PHYSIOLOGY 2008; 148:65-76. [PMID: 18614708 PMCID: PMC2528121 DOI: 10.1104/pp.108.122846] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 06/30/2008] [Indexed: 05/17/2023]
Abstract
ADP-glucose (Glc) pyrophosphorylase (ADP-Glc PPase) catalyzes the first committed step in starch biosynthesis. Higher plant ADP-Glc PPase is a heterotetramer (alpha(2)beta(2)) consisting of two small and two large subunits. There is increasing evidence that suggests that catalytic and regulatory properties of the enzyme from higher plants result from the synergy of both types of subunits. In Arabidopsis (Arabidopsis thaliana), two genes encode small subunits (APS1 and APS2) and four large subunits (APL1-APL4). Here, we show that in Arabidopsis, APL1 and APL2, besides their regulatory role, have catalytic activity. Heterotetramers formed by combinations of a noncatalytic APS1 and the four large subunits showed that APL1 and APL2 exhibited ADP-Glc PPase activity with distinctive sensitivities to the allosteric activator (3-phosphoglycerate). Mutation of the Glc-1-P binding site of Arabidopsis and potato (Solanum tuberosum) isoforms confirmed these observations. To determine the relevance of these activities in planta, a T-DNA mutant of APS1 (aps1) was characterized. aps1 is starchless, lacks ADP-Glc PPase activity, APS1 mRNA, and APS1 protein, and is late flowering in long days. Transgenic lines of the aps1 mutant, expressing an inactivated form of APS1, recovered the wild-type phenotype, indicating that APL1 and APL2 have catalytic activity and may contribute to ADP-Glc synthesis in planta.
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Affiliation(s)
- Tiziana Ventriglia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla-CSIC, 41092-Sevilla, Spain
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Slewinski TL, Ma Y, Baker RF, Huang M, Meeley R, Braun DM. Determining the role of Tie-dyed1 in starch metabolism: epistasis analysis with a maize ADP-glucose pyrophosphorylase mutant lacking leaf starch. J Hered 2008; 99:661-6. [PMID: 18723774 DOI: 10.1093/jhered/esn062] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In regions of their leaves, tdy1-R mutants hyperaccumulate starch. We propose 2 alternative hypotheses to account for the data, that Tdy1 functions in starch catabolism or that Tdy1 promotes sucrose export from leaves. To determine whether Tdy1 might function in starch breakdown, we exposed plants to extended darkness. We found that the tdy1-R mutant leaves retain large amounts of starch on prolonged dark treatment, consistent with a defect in starch catabolism. To further test this hypothesis, we identified a mutant allele of the leaf expressed small subunit of ADP-glucose pyrophosphorylase (agps-m1), an enzyme required for starch synthesis. We determined that the agps-m1 mutant allele is a molecular null and that plants homozygous for the mutation lack transitory leaf starch. Epistasis analysis of tdy1-R; agps-m1 double mutants demonstrates that Tdy1 function is independent of starch metabolism. These data suggest that Tdy1 may function in sucrose export from leaves.
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Affiliation(s)
- Thomas L Slewinski
- Department of Biology, 208 Mueller Lab, Pennsylvania State University, University Park, PA 16802, USA
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Georgelis N, Braun EL, Hannah LC. Duplications and functional divergence of ADP-glucose pyrophosphorylase genes in plants. BMC Evol Biol 2008; 8:232. [PMID: 18700010 PMCID: PMC2529307 DOI: 10.1186/1471-2148-8-232] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Accepted: 08/12/2008] [Indexed: 11/23/2022] Open
Abstract
Background ADP-glucose pyrophosphorylase (AGPase), which catalyses a rate limiting step in starch synthesis, is a heterotetramer comprised of two identical large and two identical small subunits in plants. Although the large and small subunits are equally sensitive to activity-altering amino acid changes when expressed in a bacterial system, the overall rate of non-synonymous evolution is ~2.7-fold greater for the large subunit than for the small subunit. Herein, we examine the basis for their different rates of evolution, the number of duplications in both large and small subunit genes and document changes in the patterns of AGPase evolution over time. Results We found that the first duplication in the AGPase large subunit family occurred early in the history of land plants, while the earliest small subunit duplication occurred after the divergence of monocots and eudicots. The large subunit also had a larger number of gene duplications than did the small subunit. The ancient duplications in the large subunit family raise concern about the saturation of synonymous substitutions, but estimates of the absolute rate of AGPase evolution were highly correlated with estimates of ω (the non-synonymous to synonymous rate ratio). Both subunits showed evidence for positive selection and relaxation of purifying selection after duplication, but these phenomena could not explain the different evolutionary rates of the two subunits. Instead, evolutionary constraints appear to be permanently relaxed for the large subunit relative to the small subunit. Both subunits exhibit branch-specific patterns of rate variation among sites. Conclusion These analyses indicate that the higher evolutionary rate of the plant AGPase large subunit reflects permanent relaxation of constraints relative to the small subunit and they show that the large subunit genes have undergone more gene duplications than small subunit genes. Candidate sites potentially responsible for functional divergence within each of the AGPase subunits were investigated by examining branch-specific patterns of rate variation. We discuss the phenotypes of mutants that alter some candidate sites and strategies for examining candidate sites of presently unknown function.
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Affiliation(s)
- Nikolaos Georgelis
- Program in Plant Molecular and Cellular Biology and Horticultural Sciences, University of Florida, Gainesville, Florida 32610-0245, USA.
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Hannah LC, James M. The complexities of starch biosynthesis in cereal endosperms. Curr Opin Biotechnol 2008; 19:160-5. [PMID: 18400487 DOI: 10.1016/j.copbio.2008.02.013] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Revised: 02/11/2008] [Accepted: 02/12/2008] [Indexed: 01/10/2023]
Abstract
Starch serves not only as an energy source for plants, animals, and humans but also as an environmentally friendly alternative for fossil fuels. Here, we describe recent findings concerning the synthesis of this important molecule in the cereal endosperm. Results from six separate transgenic reports point to the importance of adenosine diphosphate glucose pyrophosphorylase in controlling the amount of starch synthesized. The unexpected cause underlying the contrast in sequence divergence of its two subunits is also described. A major unresolved question concerning the synthesis of starch is the origin of nonrandom or clustered alpha-1,6 branch-points within the major component of starch, amylopectin. Developing evidence that several of the starch biosynthetic enzymes involved in amylopectin synthesis occur in complexes is reviewed. These complexes may provide the specificity for the formation of nonrandom branch-points.
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Affiliation(s)
- L Curtis Hannah
- University of Florida, Program in Plant Molecular and Cellular Biology & Department of Horticultural Sciences, P.O. Box 110690, 2211 Fifield Hall, Gainesville, FL 32611, USA
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Hwang SK, Nagai Y, Kim D, Okita TW. Direct Appraisal of the Potato Tuber ADP-glucose Pyrophosphorylase Large Subunit in Enzyme Function by Study of a Novel Mutant Form. J Biol Chem 2008; 283:6640-7. [DOI: 10.1074/jbc.m707447200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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