OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 145/1/17    most recent pp.107.104224v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Edner, C. Articles by Ritte, G. Search for Related Content PubMed PubMed Citation Articles by Edner, C. Articles by Ritte, G. Agricola Articles by Edner, C. Articles by Ritte, G.

BIOCHEMICAL PROCESSES AND MACROMOLECULAR STRUCTURES

Glucan, Water Dikinase Activity Stimulates Breakdown of Starch Granules by Plastidial -Amylases^1,[W],[OA]

Plant Physiology, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany (C.E., T.A., S.M., M.H., M.S., G.R.); Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (J.L., S.M.S.); Molecular Biology, University Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia (H.H.); and Department of Environmental Horticulture, University of Florida, Gainesville, Florida 32611 (F.K., C.G.)

Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them -AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized -amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.

The author responsible for the distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Gerhard Ritte (ritte{at}uni-potsdam.de).

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.107.104224

^* Corresponding author; e-mail ritte{at}uni-potsdam.de.

Received June 18, 2007; accepted July 11, 2007; published July 13, 2007.

This article has been cited by other articles:

				J. Fettke, M. Hejazi, J. Smirnova, E. Hochel, M. Stage, and M. Steup Eukaryotic starch degradation: integration of plastidial and cytosolic pathways J. Exp. Bot., March 26, 2009; (2009) erp054v1. [Abstract] [Full Text] [PDF]

				S. Dam, B. S. Laursen, J. H. Ornfelt, B. Jochimsen, H. H. Staerfeldt, C. Friis, K. Nielsen, N. Goffard, S. Besenbacher, L. Krusell, et al. The Proteome of Seed Development in the Model Legume Lotus japonicus Plant Physiology, March 1, 2009; 149(3): 1325 - 1340. [Abstract] [Full Text] [PDF]

				O. Kotting, D. Santelia, C. Edner, S. Eicke, T. Marthaler, M. S. Gentry, S. Comparot-Moss, J. Chen, A. M. Smith, M. Steup, et al. STARCH-EXCESS4 Is a Laforin-Like Phosphoglucan Phosphatase Required for Starch Degradation in Arabidopsis thaliana PLANT CELL, January 1, 2009; 21(1): 334 - 346. [Abstract] [Full Text] [PDF]

				S. Streb, T. Delatte, M. Umhang, S. Eicke, M. Schorderet, D. Reinhardt, and S. C. Zeeman Starch Granule Biosynthesis in Arabidopsis Is Abolished by Removal of All Debranching Enzymes but Restored by the Subsequent Removal of an Endoamylase PLANT CELL, December 1, 2008; 20(12): 3448 - 3466. [Abstract] [Full Text] [PDF]

				J. Fettke, A. Nunes-Nesi, J. Alpers, M. Szkop, A. R. Fernie, and M. Steup Alterations in Cytosolic Glucose-Phosphate Metabolism Affect Structural Features and Biochemical Properties of Starch-Related Heteroglycans Plant Physiology, November 1, 2008; 148(3): 1614 - 1629. [Abstract] [Full Text] [PDF]

				F. Wattebled, V. Planchot, Y. Dong, N. Szydlowski, B. Pontoire, A. Devin, S. Ball, and C. D'Hulst Further Evidence for the Mandatory Nature of Polysaccharide Debranching for the Aggregation of Semicrystalline Starch and for Overlapping Functions of Debranching Enzymes in Arabidopsis Leaves Plant Physiology, November 1, 2008; 148(3): 1309 - 1323. [Abstract] [Full Text] [PDF]

				P. Deschamps, H. Moreau, A. Z. Worden, D. Dauvillee, and S. G. Ball Early Gene Duplication Within Chloroplastida and Its Correspondence With Relocation of Starch Metabolism to Chloroplasts Genetics, April 1, 2008; 178(4): 2373 - 2387. [Abstract] [Full Text] [PDF]

				D. C. Fulton, M. Stettler, T. Mettler, C. K. Vaughan, J. Li, P. Francisco, M. Gil, H. Reinhold, S. Eicke, G. Messerli, et al. {beta}-AMYLASE4, a Noncatalytic Protein Required for Starch Breakdown, Acts Upstream of Three Active {beta}-Amylases in Arabidopsis Chloroplasts PLANT CELL, April 1, 2008; 20(4): 1040 - 1058. [Abstract] [Full Text] [PDF]

				P. Deschamps, C. Colleoni, Y. Nakamura, E. Suzuki, J.-L. Putaux, A. Buleon, S. Haebel, G. Ritte, M. Steup, L. I. Falcon, et al. Metabolic Symbiosis and the Birth of the Plant Kingdom Mol. Biol. Evol., March 1, 2008; 25(3): 536 - 548. [Abstract] [Full Text] [PDF]

				T. Shimonaga, M. Konishi, Y. Oyama, S. Fujiwara, A. Satoh, N. Fujita, C. Colleoni, A. Buleon, J.-L. Putaux, S. G. Ball, et al. Variation in Storage {alpha}-Glucans of the Porphyridiales (Rhodophyta) Plant Cell Physiol., January 1, 2008; 49(1): 103 - 116. [Abstract] [Full Text] [PDF]

				M. A. Glaring, A. Zygadlo, D. Thorneycroft, A. Schulz, S. M. Smith, A. Blennow, and L. Baunsgaard An extra-plastidial {alpha}-glucan, water dikinase from Arabidopsis phosphorylates amylopectin in vitro and is not necessary for transient starch degradation J. Exp. Bot., November 17, 2007; (2007) erm249v1. [Abstract] [Full Text] [PDF]