Proteomic analysis of the bloodstream forms of Trypanosoma brucei grow CMM_Glu (glucose) and CMM_Gly/GlcNAc (glycerol) conditions.
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ABSTRACT: 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.
INSTRUMENT(S): Q Exactive
ORGANISM(S): Trypanosoma Brucei
DISEASE(S): Trypanosomiasis
SUBMITTER: Dupuy Jean-William
LAB HEAD: Bringaud Frédéric
PROVIDER: PXD009763 | Pride | 2018-10-22
REPOSITORIES: Pride
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