Cargando…
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...
Autores principales: | , , , , , |
---|---|
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 |
_version_ | 1782239948752027648 |
---|---|
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. |
format | Online Article Text |
id | pubmed-3412276 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Blackwell Publishing Ltd |
record_format | MEDLINE/PubMed |
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 |
work_keys_str_mv | AT kuettelsabine thedenovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT wadummajkenct thedenovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT guthermarialucias thedenovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT marinokarina thedenovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT riemercarolin thedenovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT fergusonmichaelaj thedenovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT kuettelsabine denovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT wadummajkenct denovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT guthermarialucias denovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT marinokarina denovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT riemercarolin denovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei AT fergusonmichaelaj denovoandsalvagepathwaysofgdpmannosebiosynthesisarebothsufficientforthegrowthofbloodstreamformtrypanosomabrucei |