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What is Trehalose?

α,α-1,1-glycosidic linkage. What is Trehalose?. Non-reducing disaccharide joint by two glucoses Stores carbohydrate Protects cells against various stress conditions. UDP-glucose + Glucose-6-phosphate. Trehalose-6-phosphate synthase. Trehalose-6-phosphate.

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What is Trehalose?

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  1. α,α-1,1-glycosidic linkage What is Trehalose? • Non-reducing disaccharide joint by two glucoses • Stores carbohydrate • Protects cells against various stress conditions

  2. UDP-glucose + Glucose-6-phosphate Trehalose-6-phosphate synthase Trehalose-6-phosphate Trehalose-6-phosphate phosphotase How is Trehalose Made? Trehalose

  3. Where is Trehalose Found? • Before 1997, trehalose was thought to be present in a few desiccation-tolerant plants Selaginella lepidophylla Resurrection Plants

  4. Trehalose in Saccharomyces cerevisiae • In yeast, TPS and TPP function together as a large complex to synthesize trehalose • TPS1 is found to be important in regulating glucose glycolysis • ATP is consumed to drive glucose catabolism • When [glucose] increases suddenly, glycolysis would use up ATP so fast that stalls metabolism • Trehalose-6-phosphate targets the initial step of glycolysis to restrict the influx of glucose into glycolysis

  5. Sugar Flux Through Glycolysis & Trehalose Metabolism in Yeast Sucrose Synthase Glucose Glycolysis Trehalose Metabolism Hexokinase

  6. Trehalose in Escherichia Coli • T-6-P synthesis is catayzed by the retaining glucosyltransferase OtsA • OtsA is structurally similar to glycogen phosphorylase, suggesting a common catalytic mechanism

  7. Is Trehalose Synthesis Pathway also Important in Plants? Trehalose is detected!! They are known to be high desiccation tolerant. Resurrection plant Resurrection bush Trehalose is undetected. Is trehalose only related to desiccation tolerance? Arabidopsis Rice

  8. Is Trehalose Present in Angiosperms? Tobacco Trehalose can be detected when enzymatic activity of trehalase is inhibited!! What is the function of trehalose (synthesis pathway)? Are there other functions, like glycolysis regulation, than high desiccation tolerance? Potato

  9. Arabidopsis Genome Contains Several Homologs of Enzymes Known to be Involved in Trehalose Synthesis Pathway.

  10. What is the Phenotype of the tps1 Mutant? Embryo development in the tps1 mutant is arrested at the torpedo stage.

  11. What is Happening at the Torpedo Stage? Torpedo stage is a kind of transition stage from cell division and differentiation to cell expansion and storage reserve accumulation.

  12. Early Torpedo Late Torpedo HXK inhibitor Is Embryo Developmental Arrest Caused by a Defect in Glycolysis Regulation? • Low level of sugar in media somehow rescues • the mutant phenotype, but not completely. • In Arabidopsis, T-6-P is not the inhibitor of HXK. • Glycolysis regulation in • trehalose synthesis pathway • is different from that in yeast. • Even inhibition of HXK • activity does not rescue • the mutant phenotype. • Disruption of regulation in • glucose influx into glycolysis is not the main reason • forthe phenotype of the tps1 mutant. What causes embryo lethal in the tps1 mutant?

  13. Can Trehalose Rescue Embryo Developmental Arrest in tps1 Mutant? As T-6-P cannot be absorbed into plant cells, this type of experiment cannot be done with T-6-P.

  14. Early Torpedo Late Torpedo In Conclusion, Trehalose-6-phosphate synthase (TPS) is important for embryo development. However, it is unclear whether the trehalose synthesis pathway itself is important for embryo development. Indeed, trehalose does not rescue the tps1 mutant phenotype. TPS could be involved in sugar signaling. As sucrose level increases dramatically in torpedo stage, this might trigger TPS involved sugar signaling, and this might be important for embryo development, other than trehalose synthesis pathway. Glycolysis regulation involving trehalose synthesis pathway in yeast is different from that in Arabodopsis.

  15. Commercial Usage of Trehalose • Producing stress-tolerent crops

  16. Commercial Values in Medical Fileds Demand for having human blood cells and platelets to have extended shelf-life • Freezing & dehydrating cells could kill a substantial numbers of them • Application of chemicals to preserve cells are not appropriate either because most of the chemicals are toxic • Trehalose might solve the problem • Non-toxic • Replaces some water in the cell to prevent uncontrolled dehydration • Stabilizes the cell membrane and prevents disintegration • Forms amorphous glass inside the cells, preventing ice crystals from forming • 90% recovery of platelets

  17. Treatment Potential of Trehalose in Huntington’s Disease • Trehalose could prevent the development of the brain pathology associated with Huntington’ disease by inhibiting aggregate formation the ine brain.

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