Dataset Information

The trypanosome UDP-glucose pyrophosphorylase is active in both the glycosomal and cytosolic compartments and is imported into glycosomes by piggybacking

ABSTRACT: Trypanosoma brucei, the etiological agent of sleeping sickness, has particular peroxisome-like organelles called glycosomes where several metabolic pathways are compartmentalized, including glycolysis. Many enzymes from sugar nucleotide biosynthetic pathways are located in this organelle, contrasting with the cytosolic localisation reported in the eukaryota domain. The UDP-glucose pyrophosphorylase (UGP), the enzyme responsible for UDP-glucose (UDP-Glc) production, is essential for growth and survival of trypanosomes. In addition, UGP is localized in both glycosomes and cytosol, raising questions about why would these parasites maintain a pathway functional in two different subcellular compartments. UGP is imported into glycosomes by piggybacking on the glycosomal protein PEPCK, which is the first evidence of piggybacking involving two proteins not functionally related, and the first report in trypanosomatids. The dataset demonstrates that UGP is present in the total cellular extract and the glycocomal fraction of the wild-type trypanosomes, while only in the total cellular extract of the PEPCK null mutant.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Trypanosoma Brucei

SUBMITTER: Dupuy Jean-William

LAB HEAD: Frédéric Bringaud

PROVIDER: PXD020190 | Pride | 2021-06-10

REPOSITORIES: Pride

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Publications

The Trypanosome UDP-Glucose Pyrophosphorylase Is Imported by Piggybacking into Glycosomes, Where Unconventional Sugar Nucleotide Synthesis Takes Place.

Villafraz Oriana O Baudouin Hélène H Mazet Muriel M Kulyk Hanna H Dupuy Jean-William JW Pineda Erika E Botté Cyrille C Inaoka Daniel Ken DK Portais Jean-Charles JC Bringaud Frédéric F

mBio 20210528 3

Glycosomes are peroxisome-related organelles of trypanosomatid parasites containing metabolic pathways, such as glycolysis and biosynthesis of sugar nucleotides, usually present in the cytosol of other eukaryotes. UDP-glucose pyrophosphorylase (UGP), the enzyme responsible for the synthesis of the sugar nucleotide UDP-glucose, is localized in the cytosol and glycosomes of the bloodstream and procyclic trypanosomes, despite the absence of any known peroxisome-targeting signal (PTS1 and PTS2). The ...[more]

PMID: 34044588

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Project description:The bloodstream forms of Trypanosoma brucei (BSF), responsible for the sleeping sickness, primarily evaluate in the blood of its mammalian hosts. The skin and the adipose tissues were recently identified as additional major sites for the parasite proliferation and transmission through its insect vector blood ingestion. Glucose is the only carbon source used by the blood parasites to feed its central metabolism, however, the metabolic behavior of the tissue-adapted parasites has not yet been addressed. Since production of glycerol is an important primary function of adipocytes, we have adapted the BSF trypanosomes to glucose-depleted and glycerol-rich growth medium (CMM_Gly/GlcNAc) and compared its metabolism and proteome with standard glucose-rich growth conditions (CMM_Glu). BSF consume 2-times more oxygen per carbon consumed in CMM_Gly/GlcNAc and is 11.5-times more sensitive to SHAM, a specific inhibitor of the alternative oxidase, which is consistent with the expected absolute requirement of the mitochondrial respiratory chain activity to convert glycerol into dihydroxyacetone phosphate. Metabolomic analyses by mass spectrometry showed that 13C-labeled glycerol is incorporated into hexose phosphates through gluconeogenesis. After several weeks of growth in CMM_Gly/GlcNAc, BSF adapt their metabolism by increasing and decreasing the rate of glycerol and glucose consumption, respectively. As expected RNAi-mediated down-regulation of glycerol kinase expression abolished glycerol degradation and is lethal for BSF growth in CMM_Gly/GlcNAc. However, the glycerol kinase activity is 7.8-fold decreased in CMM_Gly/GlcNAc, as confirms by western blotting and proteomic analyses, which suggests that the huge excess of glycerol kinase, which is not necessary for glycerol metabolism, is required for another yet undetermined non-essential function in glucose rich-conditions. Altogether these data shows that BSF trypanosomes are well adapted to glycerol-rich conditions, which could be encountered by the parasite in extravascular niches, such as skin and adipose tissues.

Project description:This model is from the article: Experimental and in silico analyses of glycolytic flux control in bloodstream form Trypanosoma brucei. Albert MA, Haanstra JR, Hannaert V, Van Roy J, Opperdoes FR, Bakker BM, Michels PA. J Biol Chem2005 Aug 5;280(31):28306-15. 15955817, Abstract: A mathematical model of glycolysis in bloodstream form Trypanosoma brucei was developed previously on the basis of all available enzyme kinetic data (Bakker, B. M., Michels, P. A. M., Opperdoes, F. R., and Westerhoff, H. V. (1997) J. Biol. Chem. 272, 3207-3215). The model predicted correctly the fluxes and cellular metabolite concentrations as measured in non-growing trypanosomes and the major contribution to the flux control exerted by the plasma membrane glucose transporter. Surprisingly, a large overcapacity was predicted for hexokinase (HXK), phosphofructokinase (PFK), and pyruvate kinase (PYK). Here, we present our further analysis of the control of glycolytic flux in bloodstream form T. brucei. First, the model was optimized and extended with recent information about the kinetics of enzymes and their activities as measured in lysates of in vitro cultured growing trypanosomes. Second, the concentrations of five glycolytic enzymes (HXK, PFK, phosphoglycerate mutase, enolase, and PYK) in trypanosomes were changed by RNA interference. The effects of the knockdown of these enzymes on the growth, activities, and levels of various enzymes and glycolytic flux were studied and compared with model predictions. Data thus obtained support the conclusion from the in silico analysis that HXK, PFK, and PYK are in excess, albeit less than predicted. Interestingly, depletion of PFK and enolase had an effect on the activity (but not, or to a lesser extent, expression) of some other glycolytic enzymes. Enzymes located both in the glycosomes (the peroxisome-like organelles harboring the first seven enzymes of the glycolytic pathway of trypanosomes) and in the cytosol were affected. These data suggest the existence of novel regulatory mechanisms operating in trypanosome glycolysis. This model originates from BioModels Database: A Database of Annotated Published Models. It is copyright (c) 2005-2012 The BioModels.net Team.For more information see the terms of use.To cite BioModels Database, please use: Li C, Donizelli M, Rodriguez N, Dharuri H, Endler L, Chelliah V, Li L, He E, Henry A, Stefan MI, Snoep JL, Hucka M, Le Novère N, Laibe C (2010) BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. BMC Syst Biol., 4:92.

Project description:Water soluble carbohydrates (WSC, composed of mainly fructans, sucrose, glucose and fructose) deposited in wheat stems are important carbon sources for grain filling. Variation in stem WSC concentrations among wheat genotypes is one of the genetic factors influencing grain weight and yield under water-limited environments. Here, we describe the molecular dissection of carbohydrate metabolism in stems, at the WSC accumulation phase, of recombinant inbred SB (Seri/Babax) lines of Triticum aestivum differing in stem WSC concentrations. Affymetrix GeneChip analysis of carbohydrate metabolic enzymes revealed that the mRNA levels of two fructan synthetic enzyme families (sucrose:sucrose 1-fructosyltransferase and sucrose:fructan 6-fructosyltransferase) in the stem were positively correlated with stem WSC and fructan concentrations, while the mRNA levels of enzyme families involved in sucrose hydrolysis (sucrose synthase and soluble acid invertase) were inversely correlated with WSC concentrations. Differential regulation of the mRNA levels of these sucrose hydrolytic enzymes in SB lines resulted in genotypic differences in these enzyme activities. Down-regulation of sucrose synthase and soluble acid invertase in high WSC lines was accompanied by significant decreases in the mRNA levels of enzyme families related to sugar catabolic pathways (fructokinase and mitochondrion pyruvate dehydrogenase complex) and enzyme families involved in diverting UDP-glucose to cell wall synthesis (UDP-glucose 6-dehydrogenase, UDP-glucuronate decarboxylase and cellulose synthase), resulting in a reduction in cell wall polysaccharide contents (mainly hemicellulose) in the stem of high WSC lines. These data suggest that differential carbon partitioning in the wheat stem is one mechanism that contributes to genotypic variation in WSC accumulation. We used Affymetrix GeneChip to dissect genotypic variation in carbohydrate metabolism related to water soluble carbohydrate accumulation in stems of wheat. Experiment Overall Design: 8 genotypes of recombinant inbred lines Seri M82 x Babax with 2 biological replicates per genotype. Grown in the field under rain-fed conditions

Dataset Information

The trypanosome UDP-glucose pyrophosphorylase is active in both the glycosomal and cytosolic compartments and is imported into glycosomes by piggybacking

Publications

The Trypanosome UDP-Glucose Pyrophosphorylase Is Imported by Piggybacking into Glycosomes, Where Unconventional Sugar Nucleotide Synthesis Takes Place.

Similar Datasets

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