The tegument of the human parasitic worm Schistosoma mansoni as an excretory organ: the surface aquaporin SmAQP is a lactate transporter.

ABSTRACT: Adult schistosomes are intravascular parasites that metabolize imported glucose largely via glycolysis. How the parasites get rid of the large amounts of lactic acid this generates is unknown at the molecular level. Here, we report that worms whose aquaporin gene (SmAQP) has been suppressed using RNAi fail to rapidly acidify their culture medium and excrete less lactate compared to controls. Functional expression of SmAQP in Xenopus oocytes demonstrates that this protein can transport lactate following Michaelis-Menten kinetics with low apparent affinity (Km = 41+/-5. 8 mM) and with a low energy of activation (E(a) = 7.18+/-0.7 kcal/mol). Phloretin, a known inhibitor of lactate release from schistosomes, also inhibits lactate movement in SmAQP-expressing oocytes. In keeping with the substr

SUBMITTER: Faghiri Z 

PROVIDER: S-EPMC2862721 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature