Isotopomer profiling of leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth

Saunders, Eleanor C., Ng, William W., Chambers, Jennifer M., Ng, Milica, Naderer, Thomas, Kromer, Jens O., Likic, Vladimir A. and McConville, Malcolm J. (2011) Isotopomer profiling of leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth. Journal of Biological Chemistry, 286 31: 27706-27717. doi:10.1074/jbc.M110.213553

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
UQ245887_OA.pdf Full text (open access) application/pdf 2.88MB 0

Author Saunders, Eleanor C.
Ng, William W.
Chambers, Jennifer M.
Ng, Milica
Naderer, Thomas
Kromer, Jens O.
Likic, Vladimir A.
McConville, Malcolm J.
Title Isotopomer profiling of leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth
Journal name Journal of Biological Chemistry   Check publisher's open access policy
ISSN 0021-9258
1083-351X
Publication date 2011-08
Sub-type Article (original research)
DOI 10.1074/jbc.M110.213553
Open Access Status File (Publisher version)
Volume 286
Issue 31
Start page 27706
End page 27717
Total pages 12
Place of publication Bethesda, MD, United States
Publisher American Society for Biochemistry and Molecular Biology
Collection year 2012
Language eng
Formatted abstract
Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various 13C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and 13C NMR. [U-13C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD + consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate(glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U- 13C]aspartate and [U-13C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolismin Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions.
Keyword Procyclic trypanosoma-brucei
Phosphoglycerate kinase genes
Carbon metabolism
Energy-metabolism
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
Australian Institute for Bioengineering and Nanotechnology Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 36 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 42 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 21 Aug 2011, 01:47:19 EST by System User on behalf of Aust Institute for Bioengineering & Nanotechnology