Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cellular and molecular remodeling of the endocytic pathway during differentiation of Trypanosoma brucei bloodstream forms.

ABSTRACT: During the course of mammalian infection, African trypanosomes undergo extensive cellular differentiation, as actively dividing long slender (SL) forms progressively transform into intermediate (I) forms and finally quiescent G(1)/G(0)-locked short stumpy (ST) forms. ST forms maintain adaptations compatible with their survival in the mammalian bloodstream, such as high endocytic activity, but they already show preadaptations to the insect midgut conditions. The nutritional requirements of ST forms must differ from those of SL forms because the ST forms stop multiplying. We report that the uptake of several ligands was reduced in ST forms compared with that in SL forms. In particular, the haptoglobin-hemoglobin (Hp-Hb) complex was no longer taken up due to dramatic downregulation of its cognate receptor, TbHpHbR. As this receptor also allows uptake of trypanolytic particles from human serum, ST forms were resistant to trypanolysis by human serum lipoproteins. These observations allowed both flow cytometry analysis of SL-to-ST differentiation and the generation of homogeneous ST populations after positive selection upon exposure to trypanolytic particles. In addition, we observed that in ST forms the lysosome relocates anterior to the nucleus. Altogether, we identified novel morphological and molecular features that characterize SL-to-ST differentiation.

SUBMITTER: Vanhollebeke B

PROVIDER: S-EPMC2918936 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

A Mitogen-activated protein kinase controls differentiation of bloodstream forms of Trypanosoma brucei.

Project description:African trypanosomes undergo differentiation in order to adapt to the mammalian host and the tsetse fly vector. To characterize the role of a mitogen-activated protein (MAP) kinase homologue, TbMAPK5, in the differentiation of Trypanosoma brucei, we constructed a knockout in procyclic (insect) forms from a differentiation-competent (pleomorphic) stock. Two independent knockout clones proliferated normally in culture and were not essential for other life cycle stages in the fly. They were also able to infect immunosuppressed mice, but the peak parasitemia was 16-fold lower than that of the wild type. Differentiation of the proliferating long slender to the nonproliferating short stumpy bloodstream form is triggered by an autocrine factor, stumpy induction factor (SIF). The knockout differentiated prematurely in mice and in culture, suggestive of increased sensitivity to SIF. In contrast, a null mutant of a cell line refractory to SIF was able to proliferate normally. The differentiation phenotype was partially rescued by complementation with wild-type TbMAPK5 but exacerbated by introduction of a nonactivatable mutant form. Our results indicate a regulatory function for TbMAPK5 in the differentiation of bloodstream forms of T. brucei that might be exploitable as a target for chemotherapy against human sleeping sickness.

| S-EPMC1489280 | biostudies-literature

RNAi against DRBD18 in Trypanosoma brucei bloodstream forms

Project description:RNAi against DRBD18 in Trypanosoma brucei bloodstream forms

2021-06-29 | E-MTAB-9783 | biostudies-arrayexpress

Novel sterol metabolic network of Trypanosoma brucei procyclic and bloodstream forms.

Project description:Trypanosoma brucei is the protozoan parasite that causes African trypanosomiasis, a neglected disease of people and animals. Co-metabolite analysis, labelling studies using [methyl-2H3]-methionine and substrate/product specificities of the cloned 24-SMT (sterol C24-methyltransferase) and 14-SDM (sterol C14demethylase) from T. brucei afforded an uncommon sterol metabolic network that proceeds from lanosterol and 31-norlanosterol to ETO [ergosta-5,7,25(27)-trien-3β-ol], 24-DTO [dimethyl ergosta-5,7,25(27)-trienol] and ergosterol [ergosta-5,7,22(23)-trienol]. To assess the possible carbon sources of ergosterol biosynthesis, specifically 13C-labelled specimens of lanosterol, acetate, leucine and glucose were administered to T. brucei and the 13C distributions found were in accord with the operation of the acetate-mevalonate pathway, with leucine as an alternative precursor, to ergostenols in either the insect or bloodstream form. In searching for metabolic signatures of procyclic cells, we observed that the 13C-labelling treatments induce fluctuations between the acetyl-CoA (mitochondrial) and sterol (cytosolic) synthetic pathways detected by the progressive increase in 13C-ergosterol production (control<[2-(13)C]leucine<[2-(13)C]acetate<[1-(13)C]glucose) and corresponding depletion of cholesta-5,7,24-trienol. We conclude that anabolic fluxes originating in mitochondrial metabolism constitute a flexible part of sterol synthesis that is further fluctuated in the cytosol, yielding distinct sterol profiles in relation to cell demands on growth.

| S-EPMC3491665 | biostudies-literature

Mitochondrial growth during the cell cycle of Trypanosoma brucei bloodstream forms.

Project description:Mitochondrial organelles need to be replicated during cell division. Many aspects of this process have been studied in great detail, however the actual size increase and the position of organelle growth are less well understood. We use the protozoan parasite Trypanosoma brucei that contains a single mitochondrion to study organelle biogenesis by fluorescence microscopy. From the analysis of more than 1000 T. brucei bloodstream form cells of a nonsynchronous population we conclude that the mitochondrial network mostly grows from two areas along the main organelle axis, posterior and anterior of the nucleus. Loops and branches from these two areas eventually fuse to build a complex network. Together with the appearance of the division fold in the posterior part of the cell, pruning of the mitochondrial network and finally separation into the two daughter cells occurs. Overall organelle biogenesis is not continuous during cell growth and occurs mostly in the last part of the cell cycle. Furthermore, using 3D STED super resolution microscopy we reconstruct the volume of the organelle and characterize the region where the mitochondrial genome is positioned by serial block face scanning electron microscopy.

| S-EPMC5118809 | biostudies-literature

RNAi of XAC1 (Tb927.7.2780) in Trypanosoma brucei bloodstream forms

Project description:Gradient fractions of RNAi of XAC1 (Tb927.7.2780) in Trypanosoma brucei bloodstream forms. RNAi was induced using tetracycline and cell extracts were fractionated into polysomal and monosome-non-ribosome-associated fractions.

2017-12-16 | E-MTAB-6239 | biostudies-arrayexpress

Pyrimidine biosynthesis is not an essential function for Trypanosoma brucei bloodstream forms.

Project description:BackgroundAfrican trypanosomes are capable of both pyrimidine biosynthesis and salvage of preformed pyrimidines from the host, but it is unknown whether either process is essential to the parasite.Methodology/principal findingsPyrimidine requirements for growth were investigated using strictly pyrimidine-free media, with or without single added pyrimidine sources. Growth rates of wild-type bloodstream form Trypanosoma brucei brucei were unchanged in pyrimidine-free medium. The essentiality of the de novo pyrimidine biosynthesis pathway was studied by knocking out the PYR6-5 locus that produces a fusion product of orotate phosphoribosyltransferase (OPRT) and Orotidine Monophosphate Decarboxylase (OMPDCase). The pyrimidine auxotroph was dependent on a suitable extracellular pyrimidine source. Pyrimidine starvation was rapidly lethal and non-reversible, causing incomplete DNA content in new cells. The phenotype could be rescued by addition of uracil; supplementation with uridine, 2'deoxyuridine, and cytidine allowed a diminished growth rate and density. PYR6-5(-/-) trypanosomes were more sensitive to pyrimidine antimetabolites and displayed increased uracil transport rates and uridine phosphorylase activity. Pyrimidine auxotrophs were able to infect mice although the infection developed much more slowly than infection with the parental, prototrophic trypanosome line.Conclusions/significancePyrimidine salvage was not an essential function for bloodstream T. b. brucei. However, trypanosomes lacking de novo pyrimidine biosynthesis are completely dependent on an extracellular pyrimidine source, strongly preferring uracil, and display reduced infectivity. As T. brucei are able to salvage sufficient pyrimidines from the host environment, the pyrimidine biosynthesis pathway is not a viable drug target, although any interruption of pyrimidine supply was lethal.

| S-EPMC3591441 | biostudies-literature

Adenylate cyclase in bloodstream forms of Trypanosoma (Trypanozoon) brucei sp.

Project description:1. The adenylate cyclase in Trypanosoma brucei is located in the plasma membrane. 2. A partial kinetic analysis of the properties of the enzyme revealed a Km for ATP of 1.75 mM and a Km for Mg2+ of 4mM. 3. At low concentrations, Mg2+ activated the enzyme directly in addition to its effect of lowering the concentration of inhibitory free ATP species. 4. At high concentrations, Mg2+ inhibited the enzyme. Furthermore, the enzyme was inhibited at any Mg2+ concentration if the concentration of ATP exceeded that of Mg2+. 5. The opposing effects of Mg2+ at low and high concentrations would be consistent with more than one binding site for Mg2+ on the enzyme. 6. A study of the patterns of product inhibition revealed little or no effect of 3':5'-cyclic AMP, but a profound inhibition by pyrophosphate, which was competitive with respect to ATP (Ki 0.135 mM). This result suggests that the substrate-binding domain on T. brucei adenylate cyclase interacts mainly with the triphosphate portion of the ATP molecule. 7. The enzyme activity was unaffected by the usual mammalian enzyme effectors glucagon, adrenaline, adenosine, GTP and guanyl-5'-yl imidodiphosphate. 8. The enzyme was not activated by fluoride, instead a powerful inhibition was found. The enzyme was also inhibited by relatively high concentrations of Ca2+ (1 mM).

| S-EPMC1186056 | biostudies-other

RIP-Seq of HnRNPF/H in Trypanosoma brucei bloodstream forms

Project description:mRNAs associates with HnRNPF/H in Trypanosoma brucei bloodstream forms

2021-08-31 | E-MTAB-10708 | biostudies-arrayexpress

Effect of ZC3H28 depletion (RNAi) in Trypanosoma brucei bloodstream forms

Project description:Bloodstream-form trypanosomes with inducible RNAi targeting ZC3H28 were incubated with the tetracycline inducer for 10h, cells without tetracycline were used as controls. This experiment was done in triplicates. In another similar experiment, bloodstream-form trypanosomes with inducible RNAi targeting ZC3H28 were incubated with the tetracycline inducer for 14h, 16h, and 24h. Cells without tetracycline (named ''no tet'' or ''0h'') were used as controls. This experiment was done in duplicates.

2021-07-31 | E-MTAB-10751 | biostudies-arrayexpress

Trypanosoma brucei FKBP12 differentially controls motility and cytokinesis in procyclic and bloodstream forms.

Project description:FKBP12 proteins are able to inhibit TOR kinases or calcineurin phosphatases upon binding of rapamycin or FK506 drugs, respectively. The Trypanosoma brucei FKBP12 homologue (TbFKBP12) was found to be a cytoskeleton-associated protein with specific localization in the flagellar pocket area of the bloodstream form. In the insect procyclic form, RNA interference-mediated knockdown of TbFKBP12 affected motility. In bloodstream cells, depletion of TbFKBP12 affected cytokinesis and cytoskeleton architecture. These last effects were associated with the presence of internal translucent cavities limited by an inside-out configuration of the normal cell surface, with a luminal variant surface glycoprotein coat lined up by microtubules. These cavities, which recreated the streamlined shape of the normal trypanosome cytoskeleton, might represent unsuccessful attempts for cell abscission. We propose that TbFKBP12 differentially affects stage-specific processes through association with the cytoskeleton.

| S-EPMC3571288 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data