Proteases of haematophagous arthropod vectors are involved in blood-feeding, yolk formation and immunity - a review.

Ticks, triatomines, mosquitoes and sand flies comprise a large number of haematophagous arthropods considered vectors of human infectious diseases. While consuming blood to obtain the nutrients necessary to carry on life functions, these insects can transmit pathogenic microorganisms to the vertebrate host. Among the molecules related to the blood-feeding habit, proteases play an essential role. In this review, we provide a panorama of proteases from arthropod vectors involved in haematophagy, in digestion, in egg development and in immunity. As these molecules act in central biological processes, proteases from haematophagous vectors of infectious diseases may influence vector competence to transmit pathogens to their prey, and thus could be valuable targets for vectorial control.

Characterization of PfDYN2, a dynamin-like protein of Plasmodium falciparum expressed in schizonts.

Dynamin superfamily members are large GTPases conserved through evolution mainly described as mechanochemical enzymes involved in membrane scission events. The Plasmodium falciparum dynamin-2 (Pfdyn2) gene was cloned from the FcB1 strain. PfDYN2 belongs to the dynamin-like protein subgroup of the dynamin superfamily since it possesses a large GTPase domain together with the conserved dynamin_M and GED domains. Recombinant PfDYN2 was able to bind GTP, to hydrolyze GTP into GDP and to self-associate in low-salt conditions. PfDYN2 expression was restricted to schizonts where it localized in punctuate structures within the parasite cytoplasm. PfDYN2 partly co-localized with markers of the parasite endoplasmic reticulum, Golgi apparatus and apicoplast, suggesting it could be implicated in vesicular trafficking and/or organelle fission events known to occur during the last hours of the parasite development in erythrocytes. PfDYN2 and the previously described PfDYN1 are the only two dynamin superfamily members identified in the P. falciparum genome and the available data suggest that this situation is conserved in the Apicomplexa phylum.