Document Detail

Malaria parasites tolerate a broad range of ionic environments and do not require host cation remodelling.
MedLine Citation:
PMID:  23347042     Owner:  NLM     Status:  MEDLINE    
Malaria parasites grow within erythrocytes, but are also free in host plasma between cycles of asexual replication. As a result, the parasite is exposed to fluctuating levels of Na(+) and K(+) , ions assumed to serve important roles for the human pathogen, Plasmodium falciparum. We examined these assumptions and the parasite's ionic requirements by establishing continuous culture in novel sucrose-based media. With sucrose as the primary osmoticant and K(+) and Cl(-) as the main extracellular ions, we obtained parasite growth and propagation at rates indistinguishable from those in physiological media. These conditions abolish long-known increases in intracellular Na(+) via parasite-induced channels, excluding a requirement for erythrocyte cation remodelling. We also dissected Na(+) , K(+) and Cl(-) requirements and found that unexpectedly low concentrations of each ion meet the parasite's demands. Surprisingly, growth was not adversely affected by up to 148 mM K(+) , suggesting that low extracellular K(+) is not an essential trigger for erythrocyte invasion. At the same time, merozoite egress and invasion required a threshold ionic strength, suggesting critical electrostatic interactions between macromolecules at these stages. These findings provide insights into transmembrane signalling in malaria and reveal fundamental differences between host and parasite ionic requirements.
Ajay D Pillai; Rachel Addo; Paresh Sharma; Wang Nguitragool; Prakash Srinivasan; Sanjay A Desai
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Intramural; Research Support, Non-U.S. Gov't     Date:  2013-02-26
Journal Detail:
Title:  Molecular microbiology     Volume:  88     ISSN:  1365-2958     ISO Abbreviation:  Mol. Microbiol.     Publication Date:  2013 Apr 
Date Detail:
Created Date:  2013-03-25     Completed Date:  2013-09-26     Revised Date:  2014-04-02    
Medline Journal Info:
Nlm Unique ID:  8712028     Medline TA:  Mol Microbiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  20-34     Citation Subset:  IM    
Copyright Information:
Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
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MeSH Terms
Cations / pharmacology*
Chlorides / pharmacology
Culture Media / pharmacology
Cytosol / drug effects,  metabolism
Erythrocytes / drug effects,  parasitology,  ultrastructure
Host-Parasite Interactions
Malaria / parasitology*
Merozoites / drug effects,  growth & development
Osmolar Concentration
Parasites / drug effects*,  growth & development
Phosphates / metabolism
Plasmodium falciparum / drug effects*,  growth & development
Potassium / pharmacology
Sodium / pharmacology
Sucrose / pharmacology
Trophozoites / drug effects,  growth & development,  ultrastructure
Grant Support
Reg. No./Substance:
0/Cations; 0/Chlorides; 0/Culture Media; 0/Phosphates; 57-50-1/Sucrose; 9NEZ333N27/Sodium; RWP5GA015D/Potassium
Comment In:
Mol Microbiol. 2013 Apr;88(1):1-4   [PMID:  23421761 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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