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Functional expression and characterization of the Trypanosoma brucei procyclic glucose transporter, THT2.
Barrett MP
,
Tetaud E
,
Seyfang A
,
Bringaud F
,
Baltz T
.
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The gene encoding THT2, one of two hexose-transporter isoforms present in Trypanosoma brucei, has been expressed in both Xenopus laevis oocytes and a stably transfected line of Chinese hamster ovary (CHO) cells. The heterologously expressed gene encodes a protein with pharmacological and kinetic parameters similar to those of the hexose transporter measured in procyclic-culture-form trypanosomes. The substrate recognition of the THT2 transporter differed from that of the THT1 isoform, which is expressed only in bloodstream forms, in that: (i) it has a relatively high affinity for substrate with a Km of 59 microM for 2-deoxy-D-glucose (2-DOG) and a similar high affinity for D-glucose (compared with Km of 0.5 mM for 2-DOG in bloodstream forms); (ii) the affinity for 6-deoxy-D-glucose (6-DOG) is two orders of magnitude lower than that for D-glucose, whereas the bloodstream-form transporter recognizes D-glucose and its 6-DOG analogue with similar affinity; (iii) the bloodstream-form transporter, but not THT2, recognizes 3-fluoro-3-deoxy-D-glucose. D-Fructose-transport capacity and insensitivity to D-galactose was also found in THT2-expressing CHO cells and procyclic trypanosomes. We conclude from these cumulative results that the THT2 gene encodes the transporter responsible for hexose transport in procyclic trypanosomes. The transport of 2-DOG in procyclic organisms was inhibited by both the protonophore, carbonyl cyanide 4-trifluoromethoxy phenylhydrazone (FCCP), and KCN, suggesting a requirement for a protonmotive force. However, sensitivity to these reagents depended on the external substrate concentration, with uptake being unaffected at substrate concentrations higher than 2 mM. THT2 expressed in CHO cells behaved as a facilitated transporter, and was unaffected by FCCP or KCN over the whole substrate concentration range tested.
Asano,
Domains responsible for the differential targeting of glucose transporter isoforms.
1992, Pubmed
Asano,
Domains responsible for the differential targeting of glucose transporter isoforms.
1992,
Pubmed
Bringaud,
A potential hexose transporter gene expressed predominantly in the bloodstream form of Trypanosoma brucei.
1992,
Pubmed
Bringaud,
Differential regulation of two distinct families of glucose transporter genes in Trypanosoma brucei.
1993,
Pubmed
,
Xenbase
Brun,
Cultivation and in vitro cloning or procyclic culture forms of Trypanosoma brucei in a semi-defined medium. Short communication.
1979,
Pubmed
CUNNINGHAM,
Antigenic analysis in the Trypanosoma brucei group, using the agglutination reaction.
1962,
Pubmed
Cairns,
Developmentally regulated gene from Leishmania encodes a putative membrane transport protein.
1989,
Pubmed
Chen,
Calcium phosphate-mediated gene transfer: a highly efficient transfection system for stably transforming cells with plasmid DNA.
1988,
Pubmed
Eddy,
Slip and leak models of gradient-coupled solute transport.
1980,
Pubmed
Eisenthal,
Specificity and kinetics of hexose transport in Trypanosoma brucei.
1989,
Pubmed
Evans,
The utilization of glucose and proline by culture forms of Trypanosoma brucei.
1972,
Pubmed
Fry,
Transport of D-fructose and its analogues by Trypanosoma brucei.
1993,
Pubmed
Goodwin,
Trypanosomiasis. Introduction.
1985,
Pubmed
Gruenberg,
D-Glucose transport in Trypanosoma brucei. D-Glucose transport is the rate-limiting step of its metabolism.
1978,
Pubmed
Hasegawa,
Isolation and characterization of Chinese hamster ovary cell mutants defective in glucose transport.
1990,
Pubmed
Langford,
Molecular characterization of two genes encoding members of the glucose transporter superfamily in the parasitic protozoan Leishmania donovani.
1992,
Pubmed
Langford,
Functional expression of two glucose transporter isoforms from the parasitic protozoan Leishmania enriettii.
1994,
Pubmed
,
Xenbase
Lolkema,
Uncoupling in secondary transport proteins. A mechanistic explanation for mutants of lac permease with an uncoupled phenotype.
1995,
Pubmed
Munoz-Antonia,
Differences in glucose transport between blood stream and procyclic forms of Trypanosoma brucei rhodesiense.
1991,
Pubmed
Opperdoes,
Compartmentation of carbohydrate metabolism in trypanosomes.
1987,
Pubmed
Parsons,
Active transport of 2-deoxy-D-glucose in Trypanosoma brucei procyclic forms.
1990,
Pubmed
Seyfang,
Specificity of glucose transport in Trypanosoma brucei. Effective inhibition by phloretin and cytochalasin B.
1991,
Pubmed
Ter Kuile,
Uptake and turnover of glucose in Leishmania donovani.
1993,
Pubmed
Tetaud,
Characterization of glucose transport and cloning of a hexose transporter gene in Trypanosoma cruzi.
1994,
Pubmed
,
Xenbase
Verma,
Role of de novo protein synthesis in the interconversion of glucose transport systems in the yeast Pichia ohmeri.
1987,
Pubmed
Zilberstein,
Transport of nutrients and ions across membranes of trypanosomatid parasites.
1993,
Pubmed
Zilberstein,
Protonmotive force-driven active transport of D-glucose and L-proline in the protozoan parasite Leishmania donovani.
1985,
Pubmed
ter Kuile,
Comparative physiology of two protozoan parasites, Leishmania donovani and Trypanosoma brucei, grown in chemostats.
1992,
Pubmed