Structural organization of erythrocyte membrane microdomains and their relation with malaria susceptibility.

Cholesterol-rich microdomains are membrane compartments characterized by specific lipid and protein composition. These dynamic assemblies are involved in several biological processes, including infection by intracellular pathogens. This work provides a comprehensive analysis of the composition of human erythrocyte membrane microdomains.

A Comprehensive Gender-related Secretome of Sexual Stages.

, the malaria parasite, undergoes a complex life cycle alternating between a vertebrate host and a mosquito vector of the genus In red blood cells of the vertebrate host, multiplies asexually or differentiates into gamete precursors, the male and female gametocytes, responsible for parasite transmission. Sexual stage maturation occurs in the midgut of the mosquito vector, where male and female gametes egress from the host erythrocytes to fuse and form a zygote. Gamete egress entails the successive rupture of two membranes surrounding the parasite, the parasitophorous vacuole membrane and the erythrocyte plasma membrane.

An Integrated Approach to Explore Composition and Dynamics of Cholesterol-rich Membrane Microdomains in Sexual Stages of Malaria Parasite.

Membrane microdomains that include lipid rafts, are involved in key physiological and pathological processes and participate in the entry of endocellular pathogens. These assemblies, enriched in cholesterol and sphingolipids, form highly dynamic, liquid-ordered phases that can be separated from the bulk membranes thanks to their resistance to solubilization by nonionic detergents. To characterize complexity and dynamics of detergent-resistant membranes of sexual stages of the rodent malaria parasite , here we propose an integrated study of raft components based on proteomics, lipid analysis and bioinformatics.

Proteomic analysis of detergent-resistant membrane microdomains in trophozoite blood stage of the human malaria parasite Plasmodium falciparum.

Intracellular pathogens contribute to a significant proportion of infectious diseases worldwide. The successful strategy of evading the immune system by hiding inside host cells is common to all the microorganism classes, which exploit membrane microdomains, enriched in cholesterol and sphingolipids, to invade and colonize the host cell. These assemblies, with distinct biochemical properties, can be isolated by means of flotation in sucrose density gradient centrifugation because they are insoluble in nonionic detergents at low temperature.

Plasmodium lipid rafts contain proteins implicated in vesicular trafficking and signalling as well as members of the PIR superfamily, potentially implicated in host immune system interactions.

Plasmodium parasites, the causal agents of malaria, dramatically modify the infected erythrocyte by exporting parasite proteins into one or multiple erythrocyte compartments, the cytoplasm and the plasma membrane or beyond. Despite advances in defining signals and specific cellular compartments implicated in protein trafficking in Plasmodium-infected erythrocytes, the contribution of lipid-mediated sorting to this cellular process has been poorly investigated. In this study, we examined the proteome of cholesterol-rich membrane microdomains or lipid rafts, purified from erythrocytes infected by the rodent parasite Plasmodium berghei.

Functional genomics, new tools in malaria research.

The mosquito-transmitted unicellular parasite Plasmodium falciparum, the agent of malaria disease, still causes more than one million deaths every year in the tropical and subtropical areas of the world. New intervention strategies are needed to contrast the insurgence of resistance to effective drugs and insecticides. The complete annotated genomes of the human parasite P.

A gene-family encoding small exported proteins is conserved across Plasmodium genus.

A gene-family, named sep, encoding small exported proteins conserved across Plasmodium species has been identified. SEP proteins (13-16 kDa) contain a predicted signal peptide at the NH(2)-terminus, an internal hydrophobic region and a polymorphic, low-complexity region at the carboxy-terminus. One member of the Plasmodium berghei family, Pbsep1, encodes an integral membrane protein expressed along the entire erythrocytic cycle.