1
|
Compart J, Apriyanto A, Fettke J. Glucan, water dikinase (GWD) penetrates the starch granule surface and introduces C6 phosphate in the vicinity of branching points. Carbohydr Polym 2023; 321:121321. [PMID: 37739543 DOI: 10.1016/j.carbpol.2023.121321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/14/2023] [Accepted: 08/20/2023] [Indexed: 09/24/2023]
Abstract
Starch phosphorylation mediated by α-glucan, water dikinase is an integral part of starch metabolism. So far however, it is not fully understood. For getting deeper insights, several in vitro assays and intensive mass spectrometry analyses were performed. Such analyses allowed us to determine the phosphorylation position within the amylopectin in detail. Thus, unique features of the starch structure and GWD action were correlated. Therefore, recombinant potato GWD (Solanum tuberosum L.; StGWD) was used for detailed analyses of the phosphorylation pattern of various starches. Additionally, oil palm (Elaeis guineensis Jacq.; EgGWD) GWD was cloned and characterized, representing the first characterization of GWD of a monocot species. The distribution patterns of single phosphorylated glucan chains catalyzed by both GWDs were compared. The phosphorylation distribution patterns of both GWDs varied for different starches. It was proven that GWD phosphorylates different positions within the amylopectin of native starch granules. GWD enters the starch granule surface and phosphorylates the glucosyl units in the proximity of branching points to convert the highly ordered glucan chains into a less ordered state and to render them accessible for the downstream acting hydrolases. This enables deciphering the GWD actions and the related structural properties of starch granules.
Collapse
Affiliation(s)
- Julia Compart
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Golm, Potsdam, Germany.
| | - Ardha Apriyanto
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Golm, Potsdam, Germany.
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Golm, Potsdam, Germany.
| |
Collapse
|
2
|
Laffargue T, Moulis C, Remaud-Simeon M. Phosphorylated polysaccharides: Applications, natural abundance, and new-to-nature structures generated by chemical and enzymatic functionalization. Biotechnol Adv 2023; 65:108140. [PMID: 36958536 DOI: 10.1016/j.biotechadv.2023.108140] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/14/2023] [Accepted: 03/18/2023] [Indexed: 03/25/2023]
Abstract
Polysaccharides are foreseen as serious candidates for the future generation of polymers, as they are biosourced and biodegradable materials. Their functionalisation is an attractive way to modify their properties, thereby increasing their range of applications. Introduction of phosphate groups in polysaccharide chains for the stimulation of the immune system was first described in the nineteen seventies. Since then, the use of phosphorylated polysaccharides has been proposed in various domains, such as healthcare, water treatment, cosmetic, biomaterials, etc. These alternative usages capitalize on newly acquired physico-chemical or biological properties, leading to materials as diverse as flame-resistant agents or drug delivery systems. Phosphorylated polysaccharides are found in Nature and need to be extracted to assess their biological potential. However, they are not abundant, often present complex backbones hard to characterize, and most of them have a low phosphate content. These drawbacks have pushed forward the development of chemical phosphorylation employing a wide variety of phosphorylating agents to obtain polysaccharides with a large range of phosphate content. Chemical phosphorylation requires the use of harsh conditions and toxic, petroleum-based solvents, which hinders their exploitation in the food and health industry. Over the last 20 years, although enzymes are regiospecific catalysts that work in aqueous and mild conditions, enzymatic phosphorylation has been little investigated. To date, only three families of enzymes have been used for the in vitro phosphorylation of polysaccharides. Considering the number of unresolved metabolic pathways leading to phosphorylated polysaccharides, the huge diversity of kinase sequences, and the recent progress in protein engineering one can envision native and engineered kinases as promising tools for polysaccharide phosphorylation.
Collapse
Affiliation(s)
- Thibaud Laffargue
- Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, CEDEX 04, F-31077 Toulouse, France
| | - Claire Moulis
- Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, CEDEX 04, F-31077 Toulouse, France
| | - Magali Remaud-Simeon
- Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, CEDEX 04, F-31077 Toulouse, France.
| |
Collapse
|
3
|
Floridean Starch and Floridoside Metabolic Pathways of Neoporphyra haitanensis and Their Regulatory Mechanism under Continuous Darkness. Mar Drugs 2021; 19:md19120664. [PMID: 34940663 PMCID: PMC8703398 DOI: 10.3390/md19120664] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 12/28/2022] Open
Abstract
Floridean starch and floridoside are the main storage carbohydrates of red algae. However, their complete metabolic pathways and the origin, function, and regulatory mechanism of their pathway genes have not been fully elucidated. In this study, we identified their metabolic pathway genes and analyzed the changes in related gene expression and metabolite content in Neoporphyra haitanensis under continuous dark conditions. Our results showed that genes from different sources, including eukaryotic hosts, cyanobacteria, and bacteria, were combined to construct floridean starch and floridoside metabolic pathways in N. haitanensis. Moreover, compared with those in the control, under continuous dark conditions, floridean starch biosynthesis genes and some degradation genes were significantly upregulated with no significant change in floridean starch content, whereas floridoside degradation genes were significantly upregulated with a significant decrease in floridoside content. This implies that floridean starch content is maintained but floridoside is consumed in N. haitanensis under dark conditions. This study elucidates the "floridean starch-floridoside" metabolic network and its gene origins in N. haitanensis for the first time.
Collapse
|
4
|
Adegbaju MS, Morenikeji OB, Borrego EJ, Hudson AO, Thomas BN. Differential Evolution of α-Glucan Water Dikinase (GWD) in Plants. PLANTS 2020; 9:plants9091101. [PMID: 32867090 PMCID: PMC7569903 DOI: 10.3390/plants9091101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/13/2020] [Accepted: 08/22/2020] [Indexed: 11/16/2022]
Abstract
The alpha-glucan water dikinase (GWD) enzyme catalyzes starch phosphorylation, an integral step in transitory starch degradation. The high phosphate content in stored starch has great industrial value, due to its physio–chemical properties making it more versatile, although the phosphate content of stored starch varies depending on the botanical source. In this study, we used various computational approaches to gain insights into the evolution of the GWD protein in 48 plant species with possible roles in enzyme function and alteration of phosphate content in their stored starch. Our analyses identified deleterious mutations, particularly in the highly conserved 5 aromatic amino acid residues in the dual tandem carbohydrate binding modules (CBM-45) of GWD protein in C. zofingiensis, G. hirsutum, A. protothecoides, P. miliaceum, and C. reinhardtii. These findings will inform experimental designs for simultaneous repression of genes coding for GWD and the predicted interacting proteins to elucidate the role this enzyme plays in starch degradation. Our results reveal significant diversity in the evolution of GWD enzyme across plant species, which may be evolutionarily advantageous according to the varying needs for phosphorylated stored starch between plants and environments.
Collapse
Affiliation(s)
- Muyiwa S. Adegbaju
- Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch 7600, South Africa;
| | - Olanrewaju B. Morenikeji
- Department of Biomedical Sciences, College of Health Science and Technology, Rochester Institute of Technology, Rochester, NY 14623, USA;
- Department of Biology, Hamilton College, Clinton, NY 14623, USA
| | - Eli J. Borrego
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA; (E.J.B.); (A.O.H.)
| | - André O. Hudson
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA; (E.J.B.); (A.O.H.)
| | - Bolaji N. Thomas
- Department of Biomedical Sciences, College of Health Science and Technology, Rochester Institute of Technology, Rochester, NY 14623, USA;
- Correspondence: ; Tel.: +1-(585)-475-6382; Fax: +1-(585)-475-5809
| |
Collapse
|
5
|
You Y, Zhang M, Yang W, Li C, Liu Y, Li C, He J, Wu W. Starch phosphorylation and the in vivo regulation of starch metabolism and characteristics. Int J Biol Macromol 2020; 159:823-831. [PMID: 32445823 DOI: 10.1016/j.ijbiomac.2020.05.156] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 12/26/2022]
Abstract
Starch is the most significant carbon and energy reserve in plants and is also a sustainable feedstock for many industrial applications. Substantial research effort has been devoted to enhancing the yield and quality of starch. Over the past century, starch phosphorylation has aroused increasing interest as the only naturally occurring covalent modification in starch. Many studies have investigated the role of phosphorylation in starch metabolism and its impact on the starch granule. In this review, the two key enzymes involved in starch phosphorylation and their catalytic mechanisms are described at the molecular level; the vital roles of phosphorylation in starch degradation and biosynthesis are illuminated in detail; and the multiple influences of phosphorylation on starch composition, granule structure and physicochemical properties are discussed. This review systematically summarizes the importance of phosphorylation in starch metabolism, and describes the advanced methods used to precisely measure phosphate and increase the level of starch phosphorylation.
Collapse
Affiliation(s)
- Yuxian You
- College of Food Science, Sichuan Agricultural University, Yaan 625014, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Mingyue Zhang
- College of Food Science, Sichuan Agricultural University, Yaan 625014, China
| | - Wen Yang
- College of Food Science, Sichuan Agricultural University, Yaan 625014, China
| | - Cheng Li
- College of Food Science, Sichuan Agricultural University, Yaan 625014, China
| | - Yuntao Liu
- College of Food Science, Sichuan Agricultural University, Yaan 625014, China.
| | - Caiming Li
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Jialiang He
- School of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China
| | - Wenjuan Wu
- College of Science, Sichuan Agricultural University, Yaan 625014, China
| |
Collapse
|
6
|
Mdodana NT, Jewell JF, Phiri EE, Smith ML, Oberlander K, Mahmoodi S, Kossmann J, Lloyd JR. Mutations in Glucan, Water Dikinase Affect Starch Degradation and Gametophore Development in the Moss Physcomitrella patens. Sci Rep 2019; 9:15114. [PMID: 31641159 PMCID: PMC6805951 DOI: 10.1038/s41598-019-51632-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 10/01/2019] [Indexed: 11/23/2022] Open
Abstract
The role of starch degradation in non-vascular plants is poorly understood. To expand our knowledge of this area, we have studied this process in Physcomitrella patens. This has been achieved through examination of the step known to initiate starch degradation in angiosperms, glucan phosphorylation, catalysed by glucan, water dikinase (GWD) enzymes. Phylogenetic analysis indicates that GWD isoforms can be divided into two clades, one of which contains GWD1/GWD2 and the other GWD3 isoforms. These clades split at a very early stage within plant evolution, as distinct sequences that cluster within each were identified in all major plant lineages. Of the five genes we identified within the Physcomitrella genome that encode GWD-like enzymes, two group within the GWD1/GWD2 clade and the others within the GWD3 clade. Proteins encoded by both loci in the GWD1/GWD2 clade, named PpGWDa and PpGWDb, are localised in plastids. Mutations of either PpGWDa or PpGWDb reduce starch phosphate abundance, however, a mutation at the PpGWDa locus had a much greater influence than one at PpGWDb. Only mutations affecting PpGWDa inhibited starch degradation. Mutants lacking this enzyme also failed to develop gametophores, a phenotype that could be chemically complemented using glucose supplementation within the growth medium.
Collapse
Affiliation(s)
- Ntombizanele T Mdodana
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - Jonathan F Jewell
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - Ethel E Phiri
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - Marthinus L Smith
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - Kenneth Oberlander
- Schweickerdt Herbarium, Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Saire Mahmoodi
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - Jens Kossmann
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - James R Lloyd
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa.
| |
Collapse
|
7
|
Tappiban P, Smith DR, Triwitayakorn K, Bao J. Recent understanding of starch biosynthesis in cassava for quality improvement: A review. Trends Food Sci Technol 2019. [DOI: 10.1016/j.tifs.2018.11.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
8
|
Alpha-Glucan, Water Dikinase 1 Affects Starch Metabolism and Storage Root Growth in Cassava (Manihot esculenta Crantz). Sci Rep 2017; 7:9863. [PMID: 28852191 PMCID: PMC5575247 DOI: 10.1038/s41598-017-10594-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 08/10/2017] [Indexed: 11/20/2022] Open
Abstract
Regulation of storage root development by source strength remains largely unknown. The cassava storage root delay (srd) T-DNA mutant postpones storage root development but manifests normal foliage growth as wild-type plants. The SRD gene was identified as an orthologue of α-glucan, water dikinase 1 (GWD1), whose expression is regulated under conditions of light/dark cycles in leaves and is associated with storage root development. The GWD1-RNAi cassava plants showed both retarded plant and storage root growth, as a result of starch excess phenotypes with reduced photosynthetic capacity and decreased levels of soluble saccharides in their leaves. These leaves contained starch granules having greatly increased amylose content and type C semi-crystalline structures with increased short chains that suggested storage starch. In storage roots of GWD1-RNAi lines, maltose content was dramatically decreased and starches with much lower phosphorylation levels showed a drastically reduced β-amylolytic rate. These results suggested that GWD1 regulates transient starch morphogenesis and storage root growth by decreasing photo-assimilation partitioning from the source to the sink and by starch mobilization in root crops.
Collapse
|
9
|
Highly phosphorylated functionalized rice starch produced by transgenic rice expressing the potato GWD1 gene. Sci Rep 2017; 7:3339. [PMID: 28611462 PMCID: PMC5469863 DOI: 10.1038/s41598-017-03637-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/02/2017] [Indexed: 11/20/2022] Open
Abstract
Starch phosphorylation occurs naturally during starch metabolism in the plant and is catalysed by glucan water dikinases (GWD1) and phosphoglucan water dikinase/glucan water dikinase 3 (PWD/GWD3). We generated six stable individual transgenic lines by over-expressing the potato GWD1 in rice. Transgenic rice grain starch had 9-fold higher 6-phospho (6-P) monoesters and double amounts of 3-phospho (3-P) monoesters, respectively, compared to control grain. The shape and topography of the transgenic starch granules were moderately altered including surface pores and less well defined edges. The gelatinization temperatures of both rice flour and extracted starch were significantly lower than those of the control and hence negatively correlated with the starch phosphate content. The 6-P content was positively correlated with amylose content and relatively long amylopectin chains with DP25-36, and the 3-P content was positively correlated with short chains of DP6-12. The starch pasting temperature, peak viscosity and the breakdown were lower but the setback was higher for transgenic rice flour. The 6-P content was negatively correlated with texture adhesiveness but positively correlated with the cohesiveness of rice flour gels. Our data demonstrate a way forward to employ a starch bioengineering approach for clean modification of starch, opening up completely new applications for rice starch.
Collapse
|
10
|
Mahlow S, Orzechowski S, Fettke J. Starch phosphorylation: insights and perspectives. Cell Mol Life Sci 2016; 73:2753-64. [PMID: 27147464 PMCID: PMC11108486 DOI: 10.1007/s00018-016-2248-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 01/12/2023]
Abstract
During starch metabolism, the phosphorylation of glucosyl residues of starch, to be more precise of amylopectin, is a repeatedly observed process. This phosphorylation is mediated by dikinases, the glucan, water dikinase (GWD) and the phosphoglucan, water dikinase (PWD). The starch-related dikinases utilize ATP as dual phosphate donor transferring the terminal γ-phosphate group to water and the β-phosphate group selectively to either C6 position or C3 position of a glucosyl residue within amylopectin. By the collaborative action of both enzymes, the initiation of a transition of α-glucans from highly ordered, water-insoluble state to a less order state is realized and thus the initial process of starch degradation. Consequently, mutants lacking either GWD or PWD reveal a starch excess phenotype as well as growth retardation. In this review, we focus on the increased knowledge collected over the last years related to enzymatic properties, the precise definition of the substrates, the physiological implications, and discuss ongoing questions.
Collapse
Affiliation(s)
- Sebastian Mahlow
- Biopolymer Analytics, University of Potsdam, Karl-Liebknecht 24-25, 14476, Potsdam-Golm, Germany
- Institute of General Botany, Friedrich Schiller University Jena, Am Planetarium 1, 07743, Jena, Germany
| | - Sławomir Orzechowski
- Biopolymer Analytics, University of Potsdam, Karl-Liebknecht 24-25, 14476, Potsdam-Golm, Germany
- Department of Biochemistry, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, 02-776, Warsaw, Poland
| | - Joerg Fettke
- Biopolymer Analytics, University of Potsdam, Karl-Liebknecht 24-25, 14476, Potsdam-Golm, Germany.
- Department of Biochemistry, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, 02-776, Warsaw, Poland.
| |
Collapse
|
11
|
Carciofi M, Shaik SS, Jensen SL, Blennow A, Svensson JT, Vincze É, Hebelstrup KH. Hyperphosphorylation of cereal starch. J Cereal Sci 2011. [DOI: 10.1016/j.jcs.2011.06.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
12
|
Pérez S, Bertoft E. The molecular structures of starch components and their contribution to the architecture of starch granules: A comprehensive review. STARCH-STARKE 2010. [DOI: 10.1002/star.201000013] [Citation(s) in RCA: 897] [Impact Index Per Article: 64.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
13
|
Wickramasinghe HAM, Blennow A, Noda T. Physico-chemical and degradative properties of in-planta re-structured potato starch. Carbohydr Polym 2009. [DOI: 10.1016/j.carbpol.2008.12.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
14
|
Chen YF, Chen RC, Chan YK, Pan RH, Hseu YC, Lin E. Design of multiplex PCR primers using heuristic algorithm for sequential deletion applications. Comput Biol Chem 2009; 33:181-8. [PMID: 19211306 DOI: 10.1016/j.compbiolchem.2008.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 09/23/2008] [Accepted: 12/26/2008] [Indexed: 10/21/2022]
Abstract
UNLABELLED The sequential deletion method is commonly applied to locate the functional domain of a protein. Unfortunately, manually designing primers for multiplex polymerase chain reaction (PCR) is a labor-intensive task. In order to speed up the experimental procedure and to improve the efficiency of producing PCR products, this paper proposes a multiplex PCR primers (MPCRPs) designer to design multiple forward primers with a single 3'-UTR reverse primer for extracting various N-terminal truncated mutants to quickly locate the functional domain of a cDNA sequence. Several factors, including melting temperature, primer length, GC content, internal self-complement, cross-dimerization, terminal limitation, and specificity, are used as the criteria for designing primers. This study obtains a near-optimal solution of primer sets that can be placed in as few test tubes as possible for one multiplex PCR experiment. RESULTS Homo sapiens ribosomal protein L5, Homo sapiens xylosyltransferase I, and Bacteriophage T4 gene product 11 were used as test examples to verify efficacy of the proposed algorithm. In addition, the designed primers of Homo sapiens ribosomal protein L5 cDNA were applied in multiplex PCR experiments. A total of 48 forward primers and one reverse primer were designed and used to duplicate N-terminal truncated mutants of different lengths from the protein. The primers were classified into eight tube groups (i.e., test tubes) held within the same temperature range (53-57 degrees C), and the validity of the PCR products were verified using polyacrylamide gel electrophoresis (PAGE) with the functional domain correctly located. A software implementation of the proposed algorithm useful in assisting the researcher to design primers for multiplex PCR experiments was developed and available upon request.
Collapse
Affiliation(s)
- Yung-Fu Chen
- Department of Health Services Administration, China Medical University, Taiwan, ROC
| | | | | | | | | | | |
Collapse
|
15
|
Fettke J, Hejazi M, Smirnova J, Höchel E, Stage M, Steup M. Eukaryotic starch degradation: integration of plastidial and cytosolic pathways. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:2907-22. [PMID: 19325165 DOI: 10.1093/jxb/erp054] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Starch is an important plant product widely used as a nutrient, as a source of renewable energy, and for many technological applications. In plants, starch is the almost ubiquitous storage carbohydrate whereas most heterotrophic prokaryotes and eukaryotes rely on glycogen. Despite close similarities in basic chemical features, starch and glycogen differ in both structural and physicochemical properties. Glycogen is a hydrosoluble macromolecule with evenly distributed branching points. Starch exists as a water-insoluble particle having a defined (and evolutionary conserved) internal structure. The biochemistry of starch requires the co-operation of up to 40 distinct (iso)enzymes whilst approximately 10 (iso)enzymes permit glycogen metabolism. The biosynthesis and degradation of native starch include the transition of carbohydrates from the soluble to the solid phase and vice versa. In this review, two novel aspects of the eukaryotic plastidial starch degradation are discussed: Firstly, biochemical reactions that take place at the surface of particulate glucans and mediate the phase transition of carbohydrates. Secondly, processes that occur downstream of the export of starch-derived sugars into the cytosol. Degradation of transitory starch mainly results in the formation of neutral sugars, such as glucose and maltose, that are transported into the cytosol via the respective translocators. The cytosolic metabolism of the neutral sugars includes the action of a hexokinase, a phosphoglucomutase, and a transglucosidase that utilizes high molecular weight glycans as a transient glucosyl acceptor or donor. Data are included on the transglucosidase (disproportionating isozyme 2) in Cyanophora paradoxa that accumulates storage carbohydrates in the cytosol rather than in the plastid.
Collapse
Affiliation(s)
- Joerg Fettke
- Institute of Biochemistry and Biology, Mass Spectrometry of Biopolymers, University of Potsdam, D-14476 Potsdam-Golm, Germany
| | | | | | | | | | | |
Collapse
|
16
|
Shiau RJ, Wen YD, Jeang CL. Identification of three proteins up-regulated by raw starch in Cytophaga sp. Arch Microbiol 2008; 190:651-5. [PMID: 18704367 DOI: 10.1007/s00203-008-0417-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Revised: 07/06/2008] [Accepted: 07/17/2008] [Indexed: 11/24/2022]
Abstract
Raw starch-digesting amylases (RSDAs) in many microorganisms convert starch granules into maltodextrins and simple sugars. We cloned and sequenced from Cytophaga sp. an RSDA with an excellent raw starch digestion activity. This RSDA was highly inducible by raw starch, but not by other sugars, suggesting that an unknown signal transduction mechanism is involved in the degradation of raw starch. We used a proteomic approach to investigate the effect of raw starch on protein expression in Cytophaga sp. Using MALDI-TOF MS protein analysis, we have identified three proteins up-regulated by raw starch, i.e., a 60-kDa chaperonin (cpn60), glutaminase, and pyruvate phosphate dikinase (PPDK). Subsequent time-course studies detected an increased expression of RSDA as well as the highest expression of PPDK occurring 6 h post-incubation with raw corn starch, implying that the latter enzyme may work along with RSDA on the digestion of raw starch. Finding these proteins up-regulated by raw starch may provide an insight into how Cytophaga sp. cells respond to raw starch stimulation.
Collapse
Affiliation(s)
- Rong-Jen Shiau
- Department of Beauty Science, Chienkuo Technology University, Changhua 500, Taiwan.
| | | | | |
Collapse
|
17
|
Kempa S, Rozhon W, Šamaj J, Erban A, Baluška F, Becker T, Haselmayer J, Schleiff E, Kopka J, Hirt H, Jonak C. A plastid-localized glycogen synthase kinase 3 modulates stress tolerance and carbohydrate metabolism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 49:1076-90. [PMID: 17319843 PMCID: PMC1865003 DOI: 10.1111/j.1365-313x.2006.03025.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2006] [Revised: 11/03/2006] [Accepted: 11/11/2006] [Indexed: 05/14/2023]
Abstract
Glycogen synthase kinase 3 (GSK-3) was originally identified as a regulator of glycogen synthesis in mammals. Like starch in plants, glycogen is a polymer of glucose, and serves as an energy and carbon store. Starch is the main carbohydrate store in plants. Regulation of starch metabolism, in particular in response to environmental cues, is of primary importance for carbon and energy flow in plants but is still obscure. Here, we provide evidence that MsK4, a novel Medicago sativa GSK-3-like kinase, connects stress signalling with carbon metabolism. MsK4 was found to be a plastid-localized protein kinase that is associated with starch granules. High-salt stress rapidly induced the in vivo kinase activity of MsK4. Metabolic profiling of MsK4 over-expressor lines revealed changes in sugar metabolism, including increased amounts of maltose, the main degradation product of starch in leaves. Plants over-expressing MsK4 showed improved tolerance to salt stress. Moreover, under high-salinity conditions, MsK4-over-expressing plants accumulated significantly more starch and showed modified carbohydrate content compared with wild-type plants. Overall, these data indicate that MsK4 is an important regulator that adjusts carbohydrate metabolism to environmental stress.
Collapse
Affiliation(s)
- Stefan Kempa
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BiocenterDr Bohrgasse 3, A-1030 Vienna, Austria
| | - Wilfried Rozhon
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BiocenterDr Bohrgasse 3, A-1030 Vienna, Austria
| | - Jozef Šamaj
- Institute of Plant Genetics and Biotechnology, Slovak Academy of SciencesAkademická 2, PO Box 39A, SK-950 07 Nitra, Slovak Republic
- Institute of Cellular and Molecular Botany, University of BonnKirschallee 1, D-53115 Bonn, Germany
| | - Alexander Erban
- Max Plank Institute of Molecular Plant BiologyAm Mühlenberg 1, D-14467 Golm, Germany
| | - František Baluška
- Institute of Cellular and Molecular Botany, University of BonnKirschallee 1, D-53115 Bonn, Germany
| | - Thomas Becker
- Department of Biology I, Ludwig-Maximilians-University MunichMenzinger Straße 67, D-80638 Munich, Germany
| | - Joachim Haselmayer
- Max F. Perutz Laboratories, University of Vienna, Vienna BiocenterDr Bohrgasse 9, A-1030 Vienna, Austria
| | - Enrico Schleiff
- Department of Biology I, Ludwig-Maximilians-University MunichMenzinger Straße 67, D-80638 Munich, Germany
| | - Joachim Kopka
- Max Plank Institute of Molecular Plant BiologyAm Mühlenberg 1, D-14467 Golm, Germany
| | - Heribert Hirt
- Max F. Perutz Laboratories, University of Vienna, Vienna BiocenterDr Bohrgasse 9, A-1030 Vienna, Austria
| | - Claudia Jonak
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BiocenterDr Bohrgasse 3, A-1030 Vienna, Austria
| |
Collapse
|