Parasitology

Table of Contents - 2006 - Volume 133, Issue 06  


Characterization of D-glucose transport in Trypanosoma rangeli

L. C. MILETTI a1c1, L. B. KOERICH a2, L. K. PACHECO a2, M. STEINDEL a2 and B. U. STAMBUK a1
a1 Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brasil
a2 Departamento de Microbiologia e Parasitologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brasil

Article author query
miletti lc   [PubMed][Google Scholar] 
koerich lb   [PubMed][Google Scholar] 
pacheco lk   [PubMed][Google Scholar] 
steindel m   [PubMed][Google Scholar] 
stambuk bu   [PubMed][Google Scholar] 

Abstract

Like in other trypanosomatids D-glucose is a crucial source of energy to Trypanosoma rangeli, a non-pathogenic parasite that in Central and South America infects triatomine vectors and different mammalian species, including humans. In several trypanosome species, D-glucose transporters were already described and cloned. In this study, we characterized the D-glucose transport activity present in 2 life-stage forms of T. rangeli (epimastigotes and trypomastigotes) using D-[U-14C]glucose as substrate. Our results indicate that T. rangeli transports D-glucose with high affinity in both epimastigote (Km 30 μM) and trypomastigotes (Km 80 μM) life-forms. Both transport activities were inhibited by Cytochalasin B and Phloretin, indicating that probably D-glucose uptake in T. rangeli is mediated by facilitated diffusion of the sugar. Significant differences were observed between epimastigotes and trypomastigotes in relation to their affinity for D-glucose analogues, and the predicted amino acid sequence of a putative D-glucose transporter from T. rangeli (TrHT1) showed a larger identity with the T. cruzi D-glucose transporter encoded by the TcrHT1 gene than with other transporters already characterized in trypanosomatids.

(Received March 6 2006)
(Revised June 12 2006)
(Accepted June 12 2003)
(Published Online August 10 2006)


Key Words: Trypanosoma rangeli; D-glucose; D-fructose; hexose transporter.

Correspondence:
c1 Departamento de Morfofisiologia, Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina, Av. Luiz de Camões, 2090 Bairro Conta Dinheiro, SC – CEP 88520-000, Brasil. Tel: +55 49 3221 2200. Fax: +55 49 3221 2222. E-mail: lcmilett@yahoo.com.br

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