Proteomic analysis of zygote and ookinete stages of the avian malaria parasite Plasmodium gallinaceum delineates the homologous proteomes of the lethal human malaria parasite Plasmodium falciparum

Abstract

Delineation of the complement of proteins comprising the zygote and ookinete, the early developmental stages of Plasmodium within the mosquito midgut, is fundamental to understand initial molecular parasite-vector interactions. The published proteome of Plasmodium falciparum does not include analysis of the zygote/ookinete stages, nor does that of P. berghei include the zygote stage or secreted proteins. P. gallinaceum zygote, ookinete, and ookinete-secreted/released protein samples were prepared and subjected to Multidimensional protein identification technology (MudPIT). Peptides of P. gallinaceum zygote, ookinete, and ookinete-secreted proteins were identified by MS/MS, mapped to ORFs (>50 amino acids) in the extent P. gallinaceum whole genome sequence, and then matched to homologous ORFs in P. falciparum. A total of 966 P. falciparum ORFs encoding orthologous proteins were identified; just over 40% of these predicted proteins were found to be hypothetical. A majority of putative proteins with predicted secretory signal peptides or transmembrane domains were hypothetical proteins. This analysis provides a more comprehensive view of the hitherto unknown proteome of the early mosquito midgut stages of P. falciparum. The results underpin more robust study of Plasmodium-mosquito midgut interactions, fundamental to the development of novel strategies of blocking malaria transmission.

Apical Surface Expression of Aspartic Protease Plasmepsin 4, a Potential Transmission-blocking Target of the Plasmodium Ookinete

“…BLAST searching showed that all four peptides were derived from a single plasmepsin gene. Independently, two-dimensional gel analysis of P. gallinaceum zygotes, ookinetes, and ookinete-secreted proteins identified PgPM4, which was also found in high throughput proteomic analysis of P. gallinaceum ookinetes (23). By searching the recently completed 3-fold coverage of P. gallinaceum genome, the four peptides were found to be encoded by a single gene, designated PgPM4 based on the highest degree of similarity to plasmepsin 4 of P. falciparum (PfPM4), P. vivax (PvPM4), Plasmodium ovale (PoPM4), and Plasmodium malariae (PmPM4) (supplemental Fig.…”

New Ultrastructural Analysis of the Invasive Apparatus of the Plasmodium Ookinete

“…51 Recently, the proteome of crystalloid bodies in Eimeria tenella, an apicomplexan protozoan that causes chicken coccidiosis, was analyzed and confirmed as a reservoir of proteins necessary for invasion and energetic and metabolic functions, 52 but such findings needs to be corroborated and extended in Plasmodium. Recent proteomic studies of Plasmodium zygote and ookinete stage proteins 53,54 will facilitate functional analysis of these sexual stage proteins by use of improved electron microscopic techniques.…”

Application of genomics to field investigations of malaria by the international centers of excellence for malaria research

“…These original genome sequences have certainly increased our understanding of parasite biology, elucidating the basic genomic structure (Carlton et al, 2008; Carlton et al, 2002; Gardner et al, 2002; Pain et al, 2008) and allowing comparisons between species (Carlton et al, 2008; Carlton et al, 2002; Kooij et al, 2005; Pain et al, 2008) to determine shared pathways among Plasmodium species that are unique to malaria. Functional genomic studies including investigation of transcription (Bozdech et al, 2003; Duraisingh et al, 2005; Foth et al, 2008; Freitas-Junior et al, 2005; Le Roch et al, 2003; Otto et al, 2010; Raabe et al, 2010), proteomics (Florens et al, 2002; Hall et al, 2005; Khan et al, 2005; Lasonder et al, 2002; Lasonder et al, 2008; Patra et al, 2008; Sinden, 2009; Wuchty et al, 2009), and metabolism (Besteiro et al, 2010; Olszewski et al, 2010; Olszewski et al, 2009; Teng et al, 2009) have also provided key insight to the basic biology of the parasite. However, the promise of simply gleaning this genomic information for development of effective drugs and vaccines has not been realized.…”