Judith Helena Prieto

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Apicomplexan parasites depend on the invasion of host cells for survival and proliferation. Calcium-dependent signaling pathways appear to be essential for micronemal release and gliding motility, yet the target of activated kinases remains largely unknown. We have characterized calcium-dependent phosphorylation events during Toxoplasma host cell invasion.(More)
We report the proteomes of four life-cycle stages of the Apicomplexan parasite Eimeria tenella. A total of 1868 proteins were identified, with 630, 699, 845 and 1532 found in early oocysts (unsporulated), late oocysts (sporulated), sporozoites and second-generation merozoites, respectively. A multidimensional protein identification technology shotgun(More)
Although the genomes of many of the most important human and animal pathogens have now been sequenced, our understanding of the actual proteins expressed by these genomes and how well they predict protein sequence and expression is still deficient. We have used three complementary approaches (two-dimensional electrophoresis, gel-liquid chromatography linked(More)
Secretion of microneme proteins is essential to Plasmodium invasion but the molecular composition of these secretory organelles remains poorly defined. Here, we describe the first Plasmodium microneme proteome. Purification of micronemes by subcellular fractionation from cultured ookinetes was confirmed by enrichment of known micronemal proteins and(More)
Coevolution of the malarial parasite and its human host has resulted in a complex network of interactions contributing to the homeodynamics of the host-parasite unit. As a rapidly growing and multiplying organism, Plasmodium falciparum depends on an adequate antioxidant defense system that is efficient despite the absence of genuine catalase and glutathione(More)
Gametogenesis and fertilization play crucial roles in malaria transmission. While male gametes are thought to be amongst the simplest eukaryotic cells and are proven targets of transmission blocking immunity, little is known about their molecular organization. For example, the pathway of energy metabolism that power motility, a feature that facilitates(More)
Clusters of complement-type ligand-binding repeats (CRs) in the low-density lipoprotein receptor (LDLR) family are thought to mediate the interactions with their various ligands. Apolipoprotein E (ApoE), a key ligand for cholesterol homeostasis, has been shown to interact with LDLR-related protein 1 (LRP) through these clusters. The segment comprising the(More)
Proteome studies contribute markedly to our understanding of parasite biology, host-parasite interactions, and mechanisms of drug action. For most antimalarial drugs neither mode of action nor mechanisms of resistance development are fully elucidated although this would be important prerequisites for successfully developing urgently required novel(More)
AIMS Due to its life in different hosts and environments, the human malaria parasite Plasmodium falciparum is exposed to oxidative and nitrosative challenges. Nitric oxide (NO) and NO-derived reactive nitrogen species can constitute nitrosative stress and play a major role in NO-related signaling. However, the mode of action of NO and its targets in P.(More)
Oxidation of Met 388, one of the three linker residues connecting the fourth and fifth EGF-like domains of thrombomodulin (TM), is deleterious for TM activity. An NMR structure of the smallest active fragment of TM (TMEGF45) and a crystal structure of a larger fragment (TMEGF456) bound to thrombin both show that Met 388 is packed into the fifth domain.(More)