This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 15/1/133    most recent tpc.006635v1 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 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 Web of Science (30) Citing Articles via Google Scholar Google Scholar Articles by Hussain, H. Articles by Bustos, R. Search for Related Content PubMed PubMed Citation Articles by Hussain, H. Articles by Bustos, R. Agricola Articles by Hussain, H. Articles by Bustos, R.

Three Isoforms of Isoamylase Contribute Different Catalytic Properties for the Debranching of Potato Glucans

^a Departments of Cell and Developmental Biology, Metabolic Biology, and Biological Chemistry, John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom
^b Plant Biochemistry Laboratory, Department of Plant Biology, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
^c Astrazeneca, 14.20 CTL, Alderley Park, Macclesfield, Cheshire SK10 4TJ, United Kingdom

² To whom correspondence should be addressed. E-mail cathie.martin{at}bbsrc.ac.uk; fax 44-1603-450045

Isoamylases are debranching enzymes that hydrolyze -1,6 linkages in -1,4/-1,6–linked glucan polymers. In plants, they have been shown to be required for the normal synthesis of amylopectin, although the precise manner in which they influence starch synthesis is still debated. cDNA clones encoding three distinct isoamylase isoforms (Stisa1, Stisa2, and Stisa3) have been identified from potato. The expression patterns of the genes are consistent with the possibility that they all play roles in starch synthesis. Analysis of the predicted sequences of the proteins suggested that only Stisa1 and Stisa3 are likely to have hydrolytic activity and that there probably are differences in substrate specificity between these two isoforms. This was confirmed by the expression of each isoamylase in Escherichia coli and characterization of its activity. Partial purification of isoamylase activity from potato tubers showed that Stisa1 and Stisa2 are associated as a multimeric enzyme but that Stisa3 is not associated with this enzyme complex. Our data suggest that Stisa1 and Stisa2 act together to debranch soluble glucan during starch synthesis. The catalytic specificity of Stisa3 is distinct from that of the multimeric enzyme, indicating that it may play a different role in starch metabolism.

This article has been cited by other articles:

				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]

				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]

				L. Li, H. Ilarslan, M. G. James, A. M. Myers, and E. S. Wurtele Genome wide co-expression among the starch debranching enzyme genes AtISA1, AtISA2, and AtISA3 in Arabidopsis thaliana J. Exp. Bot., September 20, 2007; (2007) erm180v1. [Abstract] [Full Text] [PDF]

				C. Edner, J. Li, T. Albrecht, S. Mahlow, M. Hejazi, H. Hussain, F. Kaplan, C. Guy, S. M. Smith, M. Steup, et al. Glucan, Water Dikinase Activity Stimulates Breakdown of Starch Granules by Plastidial beta-Amylases Plant Physiology, September 1, 2007; 145(1): 17 - 28. [Abstract] [Full Text] [PDF]

				T. Delatte, M. Umhang, M. Trevisan, S. Eicke, D. Thorneycroft, S. M. Smith, and S. C. Zeeman Evidence for Distinct Mechanisms of Starch Granule Breakdown in Plants J. Biol. Chem., April 28, 2006; 281(17): 12050 - 12059. [Abstract] [Full Text] [PDF]

				T. Ohdan, P. B. Francisco Jr, T. Sawada, T. Hirose, T. Terao, H. Satoh, and Y. Nakamura Expression profiling of genes involved in starch synthesis in sink and source organs of rice J. Exp. Bot., December 1, 2005; 56(422): 3229 - 3244. [Abstract] [Full Text] [PDF]

				F. Wattebled, Y. Dong, S. Dumez, D. Delvalle, V. Planchot, P. Berbezy, D. Vyas, P. Colonna, M. Chatterjee, S. Ball, et al. Mutants of Arabidopsis Lacking a Chloroplastic Isoamylase Accumulate Phytoglycogen and an Abnormal Form of Amylopectin Plant Physiology, May 1, 2005; 138(1): 184 - 195. [Abstract] [Full Text] [PDF]

				D. Dauvillee, I. S. Kinderf, Z. Li, B. Kosar-Hashemi, M. S. Samuel, L. Rampling, S. Ball, and M. K. Morell Role of the Escherichia coli glgX Gene in Glycogen Metabolism J. Bacteriol., February 15, 2005; 187(4): 1465 - 1473. [Abstract] [Full Text] [PDF]

				G. Barbier, C. Oesterhelt, M. D. Larson, R. G. Halgren, C. Wilkerson, R. M. Garavito, C. Benning, and A. P.M. Weber Comparative Genomics of Two Closely Related Unicellular Thermo-Acidophilic Red Algae, Galdieria sulphuraria and Cyanidioschyzon merolae, Reveals the Molecular Basis of the Metabolic Flexibility of Galdieria sulphuraria and Significant Differences in Carbohydrate Metabolism of Both Algae Plant Physiology, February 1, 2005; 137(2): 460 - 474. [Abstract] [Full Text] [PDF]

				A. Kubo, S. Rahman, Y. Utsumi, Z. Li, Y. Mukai, M. Yamamoto, M. Ugaki, K. Harada, H. Satoh, C. Konik-Rose, et al. Complementation of sugary-1 Phenotype in Rice Endosperm with the Wheat Isoamylase1 Gene Supports a Direct Role for Isoamylase1 in Amylopectin Biosynthesis Plant Physiology, January 1, 2005; 137(1): 43 - 56. [Abstract] [Full Text] [PDF]

				S. M. Smith, D. C. Fulton, T. Chia, D. Thorneycroft, A. Chapple, H. Dunstan, C. Hylton, S. C. Zeeman, and A. M. Smith Diurnal Changes in the Transcriptome Encoding Enzymes of Starch Metabolism Provide Evidence for Both Transcriptional and Posttranscriptional Regulation of Starch Metabolism in Arabidopsis Leaves Plant Physiology, September 1, 2004; 136(1): 2687 - 2699. [Abstract] [Full Text] [PDF]

				M. C. Posewitz, S. L. Smolinski, S. Kanakagiri, A. Melis, M. Seibert, and M. L. Ghirardi Hydrogen Photoproduction Is Attenuated by Disruption of an Isoamylase Gene in Chlamydomonas reinhardtii PLANT CELL, August 1, 2004; 16(8): 2151 - 2163. [Abstract] [Full Text] [PDF]

				N. Fujita, A. Kubo, D.-S. Suh, K.-S. Wong, J.-L. Jane, K. Ozawa, F. Takaiwa, Y. Inaba, and Y. Nakamura Antisense Inhibition of Isoamylase Alters the Structure of Amylopectin and the Physicochemical Properties of Starch in Rice Endosperm Plant Cell Physiol., June 15, 2003; 44(6): 607 - 618. [Abstract] [Full Text] [PDF]