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The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei

The sugar nucleotide GDP-mannose is essential for Trypanosoma brucei. Phosphomannose isomerase occupies a key position on the de novo pathway to GDP-mannose from glucose, just before intersection with the salvage pathway from free mannose. We identified the parasite phosphomannose isomerase gene, co...

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Autores principales: Kuettel, Sabine, Wadum, Majken C T, Güther, Maria Lucia S, Mariño, Karina, Riemer, Carolin, Ferguson, Michael A J
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Blackwell Publishing Ltd 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3412276/
https://www.ncbi.nlm.nih.gov/pubmed/22375793
http://dx.doi.org/10.1111/j.1365-2958.2012.08026.x
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author Kuettel, Sabine
Wadum, Majken C T
Güther, Maria Lucia S
Mariño, Karina
Riemer, Carolin
Ferguson, Michael A J
author_facet Kuettel, Sabine
Wadum, Majken C T
Güther, Maria Lucia S
Mariño, Karina
Riemer, Carolin
Ferguson, Michael A J
author_sort Kuettel, Sabine
collection PubMed
description The sugar nucleotide GDP-mannose is essential for Trypanosoma brucei. Phosphomannose isomerase occupies a key position on the de novo pathway to GDP-mannose from glucose, just before intersection with the salvage pathway from free mannose. We identified the parasite phosphomannose isomerase gene, confirmed that it encodes phosphomannose isomerase activity and localized the endogenous enzyme to the glycosome. We also created a bloodstream-form conditional null mutant of phosphomannose isomerase to assess the relative roles of the de novo and salvage pathways of GDP-mannose biosynthesis. Phosphomannose isomerase was found to be essential for parasite growth. However, supplementation of the medium with low concentrations of mannose, including that found in human plasma, relieved this dependence. Therefore, we do not consider phosphomannose isomerase to be a viable drug target. We further established culture conditions where we can control glucose and mannose concentrations and perform steady-state [U-(13)C]-d-glucose labelling. Analysis of the isotopic sugar composition of the parasites variant surface glycoprotein synthesized in cells incubated in 5 mM [U-(13)C]-d-glucose in the presence and absence of unlabelled mannose showed that, under physiological conditions, about 80% of GDP-mannose synthesis comes from the de novo pathway and 20% from the salvage pathway.
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spelling pubmed-34122762012-08-07 The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei Kuettel, Sabine Wadum, Majken C T Güther, Maria Lucia S Mariño, Karina Riemer, Carolin Ferguson, Michael A J Mol Microbiol Research Articles The sugar nucleotide GDP-mannose is essential for Trypanosoma brucei. Phosphomannose isomerase occupies a key position on the de novo pathway to GDP-mannose from glucose, just before intersection with the salvage pathway from free mannose. We identified the parasite phosphomannose isomerase gene, confirmed that it encodes phosphomannose isomerase activity and localized the endogenous enzyme to the glycosome. We also created a bloodstream-form conditional null mutant of phosphomannose isomerase to assess the relative roles of the de novo and salvage pathways of GDP-mannose biosynthesis. Phosphomannose isomerase was found to be essential for parasite growth. However, supplementation of the medium with low concentrations of mannose, including that found in human plasma, relieved this dependence. Therefore, we do not consider phosphomannose isomerase to be a viable drug target. We further established culture conditions where we can control glucose and mannose concentrations and perform steady-state [U-(13)C]-d-glucose labelling. Analysis of the isotopic sugar composition of the parasites variant surface glycoprotein synthesized in cells incubated in 5 mM [U-(13)C]-d-glucose in the presence and absence of unlabelled mannose showed that, under physiological conditions, about 80% of GDP-mannose synthesis comes from the de novo pathway and 20% from the salvage pathway. Blackwell Publishing Ltd 2012-04 /pmc/articles/PMC3412276/ /pubmed/22375793 http://dx.doi.org/10.1111/j.1365-2958.2012.08026.x Text en © 2012 Blackwell Publishing Ltd http://creativecommons.org/licenses/by/2.5/ Re-use of this article is permitted in accordance with the Terms and Conditions set out at http://wileyonlinelibrary.com/onlineopen#OnlineOpen_Terms
spellingShingle Research Articles
Kuettel, Sabine
Wadum, Majken C T
Güther, Maria Lucia S
Mariño, Karina
Riemer, Carolin
Ferguson, Michael A J
The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei
title The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei
title_full The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei
title_fullStr The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei
title_full_unstemmed The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei
title_short The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei
title_sort de novo and salvage pathways of gdp-mannose biosynthesis are both sufficient for the growth of bloodstream-form trypanosoma brucei
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3412276/
https://www.ncbi.nlm.nih.gov/pubmed/22375793
http://dx.doi.org/10.1111/j.1365-2958.2012.08026.x
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