Regulation of Carbohydrate Metabolism During Giardia Encystment1
| Autor: | P. Timothy Macechko, Paul A. Steimle, Timothy A. Paget, Craig D. Karr, Dorota A. Bulik, Edward L. Jarroll, J. P. Kamerling, Stanley L. Erlandsen, Johannes F.G. Vliegenthart, Harry van Keulen, Gerrit J. Gerwig |
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| Rok vydání: | 2001 |
| Předmět: |
chemistry.chemical_classification
Stimulation Metabolism Isomerase Carbohydrate Carbohydrate metabolism Biology medicine.disease_cause Microbiology carbohydrates (lipids) chemistry.chemical_compound Enzyme chemistry Biochemistry Glucosamine medicine Giardia lamblia lipids (amino acids peptides and proteins) |
| Zdroj: | The Journal of Eukaryotic Microbiology. 48:22-26 |
| ISSN: | 1550-7408 1066-5234 |
| DOI: | 10.1111/j.1550-7408.2001.tb00412.x |
| Popis: | Giardia intestinalis trophozoites encyst when they are exposed to bile. During encystment, events related to the inducible synthesis of a novel N-acetyl-d-galactosamine (GalNAc) homopolymer, occur. Within the first 6 h of encystment, mRNA for glucosamine 6-P isomerase (GPI), the first inducible enzyme unique to this pathway appears, oxygen uptake rates double from non-encysting levels, and metronidazole (MTZ) inhibits oxygen uptake. Within 12 h, GPI and its activity are detectable and OU decreases 50% from non-encysting levels; glucose's stimulation and MTZ's inhibition of oxygen uptake cease. In contrast, aspartate uptake remained constant throughout the 40 h monitored. Two genes, gpi 1 and 2 encode for GPI, but only gpi1 is expressed during encystment. Glucosamine 6-P (GlcN6P), the synthetic product of GPI, activates UDP-N-acetylglucosamine (UDP-GlcNAc) pyrophosphorylase, a downstream enzyme, 3 to 5-fold in the direction of UDP-GlcNAc synthesis. UDP-GlcNAc is epimerized to UDP-GalNAc and UDP-Ga... |
| Databáze: | OpenAIRE |
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