A putative kinase-related protein (PKRP) from Plasmodium berghei mediates infection in the midgut and salivary glands of the mosquito

Institute of Parasitology and Centre for Host-Parasite Interactions, McGill University, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, Que. H9X3V9, Canada.
International journal for parasitology (Impact Factor: 3.87). 03/2010; 40(8):979-88. DOI: 10.1016/j.ijpara.2010.02.010
Source: PubMed


The completion of the Plasmodium (malaria) life cycle in the mosquito requires the parasite to traverse first the midgut and later the salivary gland epithelium. We have identified a putative kinase-related protein (PKRP) that is predicted to be an atypical protein kinase, which is conserved across many species of Plasmodium. The pkrp gene encodes a RNA of about 5300 nucleotides that is expressed as a 90kDa protein in sporozoites. Targeted disruption of the pkrp gene in Plasmodium berghei, a rodent model of malaria, compromises the ability of parasites to infect different tissues within the mosquito host. Early infection of mosquito midgut is reduced by 58-71%, midgut oocyst production is reduced by 50-90% and those sporozoites that are produced are defective in their ability to invade mosquito salivary glands. Midgut sporozoites are not morphologically different from wild-type parasites by electron microscopy. Some sporozoites that emerged from oocysts were attached to the salivary glands but most were found circulating in the mosquito hemocoel. Our findings indicate that a signalling pathway involving PbPKRP regulates the level of Plasmodium infection in the mosquito midgut and salivary glands.

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Available from: Terry W Spithill
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    • "As control, the assays were carried out on immunoprecipitates using antisera against the CaM-dependent protein kinase-related protein PfPKRP [15]. The 295 kDa PfPKRP has an N-terminal catalytic domain (Fig. S4A) and is a homolog of the P. berghei PKRP, which plays a role for parasite transmission to the mosquito [48]. Because protein expression of PfPKRP has not yet been described in the P. falciparum blood stages, we tested the antisera in IFA prior to use in the kinase activity assays. "
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    • "Using a similar reverse genetics approach we here show that PfCLK-1/Lammer and PfCLK-2 possess important roles for erythrocytic schizogony. We were not able to KO either of the two gene loci by homologous single-crossover recombination, while isochronously the locus of the P. falciparum kinase, PFC0485w (homolog of P. berghei PKRP [Purcell et al., 2010]) was disrupted by the same strategy. Insertions of sequences at the 3 0 end of the kinases, on the other hand, which allow tagging of the gene product without affecting enzymatic activity, were feasible and resulted in the expression of Myc-tagged proteins. "
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