Abstract
The erythrocyte membrane, the entry site of the malaria parasite, has lipid microdomains referred to as the lipidrafts, which are enriched in sphingomyelin and cholesterol. Evidences have demonstrated the importance of choles-terol in structure and functions of the lipid rafts and malaria parasite invasion into erythrocytes, while that of sphin-gomyelin is poorly understood. In this study, we examined the influence of sphingomyelinase treatment on erythro-cyte lipid rafts and malaria parasite invasion into erythrocytes. Sphingomyelin was decreased by about 65% aftersphingomyelinase treatment, and sphingomyelin, cholesterol and flotillin–1, a lipid raft marker protein, were absentfrom lipid raft fractions. The treatment also significantly reduced the association of Gsαin lipid raft fractions, sug-gesting that Gsα–mediated signal transduction was impaired. More importantly, malaria parasite invasion was pre-vented by this treatment. Our study illustrates that sphingomyelin, like cholesterol, is essential for the structure andfunctions of the lipid rafts in the erythrocyte membrane and malaria parasite invasion.
