Discovery of a novel and conserved Plasmodium falciparum exported protein that is important for adhesion of PfEMP1 at the surface of infected erythrocytes.

Plasmodium falciparum virulence is linked to its ability to sequester in post-capillary venules in the human host. Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is the main variant surface antigen implicated in this process. Complete loss of parasite adhesion is linked to a large subtelomeric deletion on chromosome 9 in a number of laboratory strains such as D10 and T9-96.

Clag9 is not essential for PfEMP1 surface expression in non-cytoadherent Plasmodium falciparum parasites with a chromosome 9 deletion.

Background: The expression of the clonally variant virulence factor PfEMP1 mediates the sequestration of Plasmodium falciparum infected erythrocytes in the host vasculature and contributes to chronic infection. Non-cytoadherent parasites with a chromosome 9 deletion lack clag9, a gene linked to cytoadhesion in previous studies. Here we present new clag9 data that challenge this view and show that surface the non-cytoadherence phenotype is linked to the expression of a non-functional PfEMP1.

Dual stage synthesis and crucial role of cytoadherence-linked asexual gene 9 in the surface expression of malaria parasite var proteins.

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family members mediate the adherence of parasite-infected red blood cells (IRBCs) to various host receptors. A previous study has shown that the parasite protein, cytoadherence-linked asexual gene 9 (CLAG9), is also essential for IRBC adherence. However, how CLAG9 influences this process remains unknown.

Identification of a novel post-translational modification in Plasmodium falciparum: protein sumoylation in different cellular compartments.

SUMO (Small Ubiquitin-like MOdifier) conjugation is a post-translational modification implicated in a variety of cellular functions including transcriptional regulation, nuclear location and signal transduction. Sumoylation, although conserved and vital in eukaryotes, has not been studied in malaria parasites. Here, we identify SUMO conjugation of blood stage parasites of Plasmodium falciparum.

Leishmania DNA is rapidly degraded following parasite death: an analysis by microscopy and real-time PCR.

Control of human leishmaniases relies on appropriate diagnosis and reliable methods for monitoring chemotherapy. The current method used for estimation of parasite burden during chemotherapy patient follow-up as well as in pharmacological studies performed in experimental models involves PCR-based assays. Compared to time-consuming conventional methods, this type of Leishmania DNA detection-based method is extremely sensitive, but could fail in distinguishing viable Leishmania from slowly degenerating ones.

Transcriptome analysis of antigenic variation in Plasmodium falciparum--var silencing is not dependent on antisense RNA.

Background: Plasmodium falciparum, the causative agent of the most severe form of malaria, undergoes antigenic variation through successive presentation of a family of antigens on the surface of parasitized erythrocytes. These antigens, known as Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) proteins, are subject to a mutually exclusive expression system, and are encoded by the multigene var family. The mechanism whereby inactive var genes are silenced is poorly understood.

Apical expression of three RhopH1/Clag proteins as components of the Plasmodium falciparum RhopH complex.

The Plasmodium falciparum high molecular mass rhoptry protein ('PfRhopH') complex is important for parasite growth and comprises three distinct gene products: RhopH1, RhopH2 and RhopH3. We have previously shown that P. falciparum RhopH1 is encoded by either PFC0110w (clag3.

The Plasmodium falciparum clag9 gene encodes a rhoptry protein that is transferred to the host erythrocyte upon invasion.

The first gene characterizing the clag (cytoadherence linked asexual gene) family of Plasmodium falciparum was identified on chromosome 9. The protein product (Clag9) was implicated in cytoadhesion, the binding of infected erythrocytes to host endothelial cells, but little information on the biochemical characteristics of this protein is available. Other genes related to clag9 have been identified on different chromosomes.

Plasmodium falciparum glycogen synthase kinase-3: molecular model, expression, intracellular localisation and selective inhibitors.

Worldwide increasing resistance of Plasmodium falciparum to common anti-malaria agents calls for the urgent identification of new drugs. Glycogen synthase kinase-3 (GSK-3) represents a potential screening target for the identification of such new compounds. We have cloned PfGSK-3, the P.

Recombinant Duffy binding-like-alpha domains of Plasmodium falciparum erythrocyte membrane protein 1 elicit antibodies in rats that recognise conserved epitopes.

Plasmodium falciparum parasites remodel the surface of human erythrocytes on invasion by the insertion of parasite-derived proteins in knob-like protrusions. P. falciparum erythrocyte membrane protein 1 (PfEMP-1), a variant surface antigen, has been shown to be anchored in these knobs and mediates adhesion to various host endothelial receptors.

Regulation of antigen-specific immunoglobulin G subclasses in response to conserved and polymorphic Plasmodium falciparum antigens in an in vitro model.

Cytophilic antibodies (Abs) play a critical role in protection against Plasmodium falciparum blood stages, yet little is known about the parameters regulating production of these Abs. We used an in vitro culture system to study the subclass distribution of antigen (Ag)-specific immunoglobulin G (IgG) produced by peripheral blood mononuclear cells (PBMCs) from individuals exposed to P. falciparum or unexposed individuals.