Genetic dissection of floridean starch synthesis in the cytosol of the model dinoflagellate Crypthecodinium cohnii
- 15 December 2009
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 106 (50), 21126-21130
- https://doi.org/10.1073/pnas.0907424106
Abstract
Starch defines an insoluble semicrystalline form of storage polysaccharides restricted to Archaeplastida (red and green algae, land plants, and glaucophytes) and some secondary endosymbiosis derivatives of the latter. While green algae and land-plants store starch in plastids by using an ADP-glucose-based pathway related to that of cyanobacteria, red algae, glaucophytes, cryptophytes, dinoflagellates, and apicomplexa parasites store a similar type of polysaccharide named floridean starch in their cytosol or periplast. These organisms are suspected to store their floridean starch from UDP-glucose in a fashion similar to heterotrophic eukaryotes. However, experimental proof of this suspicion has never been produced. Dinoflagellates define an important group of both photoautotrophic and heterotrophic protists. We now report the selection and characterization of a low starch mutant of the heterotrophic dinoflagellate Crypthecodinium cohnii. We show that the sta1-1 mutation of C. cohnii leads to a modification of the UDP-glucose-specific soluble starch synthase activity that correlates with a decrease in starch content and an alteration of amylopectin structure. These experimental results validate the UDP-glucose-based pathway proposed for floridean starch synthesis.Keywords
This publication has 24 references indexed in Scilit:
- The Carbohydrate-Active EnZymes database (CAZy): an expert resource for GlycogenomicsNucleic Acids Research, 2008
- The Heterotrophic DinoflagellateCrypthecodinium cohniiDefines a Model Genetic System To Investigate Cytoplasmic Starch SynthesisEukaryotic Cell, 2008
- Early Gene Duplication Within Chloroplastida and Its Correspondence With Relocation of Starch Metabolism to ChloroplastsGenetics, 2008
- Pathway of Cytosolic Starch Synthesis in the Model Glaucophyte Cyanophora paradoxaEukaryotic Cell, 2008
- Metabolic Symbiosis and the Birth of the Plant KingdomMolecular Biology and Evolution, 2008
- Nature of the Periplastidial Pathway of Starch Synthesis in the CryptophyteGuillardia thetaEukaryotic Cell, 2006
- Evolution of Plant-Like Crystalline Storage Polysaccharide in the Protozoan Parasite Toxoplasma gondii Argues for a Red Alga AncestryJournal of Molecular Evolution, 2005
- N‐methyl‐N′‐nitro‐N‐nitrosoguanidine and UV induced mutants of the dinoflagellate Crypthecodinium cohnii*The Journal of Protozoology, 1977
- Genetic Recombination in the Dinoflagellate Crypthecodinium cohniiScience, 1974
- Evidence for sexual fusion and recombination in the dinoflagellate Crypthecodinium (Gyrodinium) cohniiNature, 1974