A putative kinase-related protein (PKRP) from Plasmodium berghei mediates infection in the midgut and salivary glands of the mosquito.
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.
Institute of Parasitology and Centre for Host-Parasite Interactions, McGill University, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, Que. H9X3V9, Canada.
Lisa A
LA
Purcell
Ricardo
R
Leitao
Takeshi
T
Ono
Stephanie K
SK
Yanow
Gabriele
G
Pradel
Terry W
TW
Spithill
Ana
A
Rodriguez
D000595:Amino Acid Sequence; D000818:Animals; D009033:Culicidae / Q000469:parasitology*; D005260:Female; D041981:Gastrointestinal Tract / Q000469:parasitology; D017353:Gene Deletion; D020869:Gene Expression Profiling; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016254:Mutagenesis, Insertional; D010962:Plasmodium berghei / Q000201:enzymology* / Q000302:isolation & purification / Q000472:pathogenicity*; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D012469:Salivary Glands / Q000469:parasitology; D017386:Sequence Homology, Amino Acid; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D015800:Protozoan Proteins; D037521:Virulence Factors; D011494:Protein Kinases