Malaria, a disease endemic in many tropical and subtropical regions, is caused by infection of the erythrocyte by the apicomplexan parasite Plasmodium. Host-cell invasion is a complex process but two Plasmodium proteins, Apical Membrane Antigen 1 (AMA1) and the Rhoptry Neck protein complex (RON), play a key role. AMA1, present on the surface of the parasite, binds tightly to the RON2 component ...

Building a cell plate during cytokinesis in plant cells requires the participation of a number of proteins in a multistep process. We previously identified phragmoplastin as a cell plate-specific protein involved in creating a tubulovesicular network at the cell plate. We report here the identification and characterization of a phragmoplastin-interacting protein, PHIP1, in Arabidopsis (Arabidop...

Host cell infection by apicomplexan parasites plays an essential role in lifecycle progression for these obligate intracellular pathogens. For most species, including the etiological agents of malaria and toxoplasmosis, infection requires active host-cell invasion dependent on formation of a tight junction - the organising interface between parasite and host cell during entry. Formation of this...

The dynamic activity of tip-localized filamentous actin (F-actin) in pollen tubes is controlled by counteracting RIC4 and RIC3 pathways downstream of the ROP1 guanosine triphosphatase promoting actin assembly and disassembly, respectively. We show here that ROP1 activation is required for both the polar accumulation and the exocytosis of vesicles at the plasma membrane apex. The apical accumula...

Using phragmoplastin as a bait, we isolated an Arabidopsis cDNA encoding a novel UDP-glucose transferase (UGT1). This interaction was confirmed by an in vitro protein--protein interaction assay using purified UGT1 and radiolabeled phragmoplastin. Protein gel blot results revealed that UGT1 is associated with the membrane fraction and copurified with the product-entrapped callose synthase comple...

During the infection process, Apicomplexa discharge their secretory organelles called micronemes, rhoptries and dense granules to sustain host cell invasion, intracellular replication and to modulate host cell pathways and immune responses. Herein, we describe the Toxoplasma gondii Deg-like serine protein (TgDegP), a rhoptry protein homologous to High temperature requirement A (HtrA) or Deg-lik...

Proteins sequestered within organelles of the apical complex of malaria merozoites are involved in erythrocyte invasion, but few of these proteins and their interaction with the host erythrocyte have been characterized. In this report we describe MAEBL, a family of erythrocyte binding proteins identified in the rodent malaria parasites Plasmodium yoelii yoelii and Plasmodium berghei. MAEBL has ...

Proteins sequestered within organelles of the apical complex of malaria merozoites are involved in erythrocyte invasion, but few of these proteins and their interaction with the host erythrocyte have been characterized. In this report we describe MAEBL, a family of erythrocyte binding proteins identified in the rodent malaria parasites Plasmodium yoelii yoelii and Plasmodium berghei. MAEBL has ...

Rhoptries are specialized secretory organelles characteristic of single cell organisms belonging to the clade Apicomplexa. These organelles play a key role in the invasion process of host cells by accumulating and subsequently secreting an unknown number of proteins mediating host cell entry. Despite their essential role, little is known about their biogenesis, components and targeting determin...