Sodium-dependent uptake of inorganic phosphate by the intracellular malaria parasite.
Nature
; 443(7111): 582-5, 2006 Oct 05.
Article
in En
| MEDLINE
| ID: mdl-17006451
ABSTRACT
As the malaria parasite, Plasmodium falciparum, grows within its host erythrocyte it induces an increase in the permeability of the erythrocyte membrane to a range of low-molecular-mass solutes, including Na+ and K+ (ref. 1). This results in a progressive increase in the concentration of Na+ in the erythrocyte cytosol. The parasite cytosol has a relatively low Na+ concentration and there is therefore a large inward Na+ gradient across the parasite plasma membrane. Here we show that the parasite exploits the Na+ electrochemical gradient to energize the uptake of inorganic phosphate (P(i)), an essential nutrient. P(i) was taken up into the intracellular parasite by a Na+-dependent transporter, with a stoichiometry of 2Na+1P(i) and with an apparent preference for the monovalent over the divalent form of P(i). A P(i) transporter (PfPiT) belonging to the PiT family was cloned from the parasite and localized to the parasite surface. Expression of PfPiT in Xenopus oocytes resulted in Na+-dependent P(i) uptake with characteristics similar to those observed for P(i) uptake in the parasite. This study provides new insight into the significance of the malaria-parasite-induced alteration of the ionic composition of its host cell.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phosphates
/
Plasmodium falciparum
/
Sodium
/
Phosphate Transport Proteins
/
Malaria
Limits:
Animals
Language:
En
Journal:
Nature
Year:
2006
Type:
Article
Affiliation country:
Australia