LaCount, D. J. et al. A protein interaction network of the malaria parasite Plasmodium falciparum. Nature 438, 103-107

Howard Hughes Medical Institute, University of Washington, Box 357730, Seattle, Washington 98195, USA.
Nature (Impact Factor: 41.46). 12/2005; 438(7064):103-7. DOI: 10.1038/nature04104
Source: PubMed

ABSTRACT Plasmodium falciparum causes the most severe form of malaria and kills up to 2.7 million people annually. Despite the global importance of P. falciparum, the vast majority of its proteins have not been characterized experimentally. Here we identify P. falciparum protein-protein interactions using a high-throughput version of the yeast two-hybrid assay that circumvents the difficulties in expressing P. falciparum proteins in Saccharomyces cerevisiae. From more than 32,000 yeast two-hybrid screens with P. falciparum protein fragments, we identified 2,846 unique interactions, most of which include at least one previously uncharacterized protein. Informatic analyses of network connectivity, coexpression of the genes encoding interacting fragments, and enrichment of specific protein domains or Gene Ontology annotations were used to identify groups of interacting proteins, including one implicated in chromatin modification, transcription, messenger RNA stability and ubiquitination, and another implicated in the invasion of host cells. These data constitute the first extensive description of the protein interaction network for this important human pathogen.

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Available from: Sudhir Sahasrabudhe, Sep 28, 2015
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    • "Expression profiling data throughout the intraerythrocytic cycle (oligonucleotide-based microarrays in both glass slide and Affymetrix formats) as well as single nucleotide polymorphism (SNP) analysis for 20 P. falciparum strains and 100 P. falciparum isolates (Jeffares et al., 2007; Mu et al., 2007; Volkman et al., 2007) are also available. Additional functional data sets include evidence of protein–protein interactions (Y2H and predicted interactome) (LaCount et al., 2005; Date and Stoeckert, 2006); Genome Ontology (GO) (Ashburner et al., 2000) and InterPro domain (Mulder et al., 2005) annotations for P. falciparum, P. vivax, P. berghei, P. yoelii, P. knowlesi and P. chabaudi; Enzyme Commission (EC) number (Ashburner et al., 2000) annotations for P. falciparum, P. yoelii and P. knowlesi (Ginsburg, 2006); and metabolic pathway assignments for P. falciparum (Ginsburg, 2006). Predictions of protein subcellular localisation (Bendtsen et al., 2004) and transmembrane domains (Krogh et al., 2001) for P. falciparum, P. vivax, P. berghei, P. yoelii, P. knowlesi and P. chabaudi are available, as well as parasite-specific predictions (P. "
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    ABSTRACT: Vaccines are one of the most effective interventions to improve public health, however, the generation of highly effective vaccines for many diseases has remained difficult. Three chronic diseases that characterise these difficulties include malaria, tuberculosis and HIV, and they alone account for half of the global infectious disease burden. The whole organism vaccine approach pioneered by Jenner in 1796 and refined by Pasteur in 1857 with the "isolate, inactive and inject" paradigm has proved highly successful for many viral and bacterial pathogens causing acute disease but has failed with respect to malaria, tuberculosis and HIV as well as many other diseases. A significant advance of the past decade has been the elucidation of the genomes, proteomes and transcriptomes of many pathogens. This information provides the foundation for new 21(st) Century approaches to identify target antigens for the development of vaccines, drugs and diagnostic tests. Innovative genome-based vaccine strategies have shown potential for a number of challenging pathogens, including malaria. We advocate that genome-based rational vaccine design will overcome the problem of poorly immunogenic, poorly protective vaccines that has plagued vaccine developers for many years.
    International Journal for Parasitology 09/2014; 44(12). DOI:10.1016/j.ijpara.2014.07.010 · 3.87 Impact Factor
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    • "Two of these proteins, the reticulocyte-binding protein and reticulocyte-binding protein 2 homologue are adhesins expressed by merozoites and have been shown to be involved in invasion of E [24], [25]. The LRR domain-containing protein (Gene bank accession # PFCO760c) is a conserved Plasmodium protein of unknown function [26]. The MATH and LRR domain-containing protein is thought to be involved in the invasion E [26], as well as the growth and survival of malaria parasites during development within the Es. "
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    ABSTRACT: Background Complement (C) is a crucial part of the innate immune system and becomes over activated during malaria, resulting in depletion of C components, especially those for lectin pathway (LP), thereby compromising the host's innate defense. In this study, involvement of P. falciparum antigens in C activation was investigated. Methods A highly synchronous culture of the Dd2 clone of P. falciparum was established in a serum free medium. Supernatants harvested from rings, trophozoites and schizonts at various parasite densities were tested for ability to activate C by quantifying amount of C3b deposited on erythrocytes (E). Uninfected sham culture was used as control. Remnants of each C pathway were determined using Wieslab complement System Screenkit (Euro-diagnostica, Sweden). To identify MBL binding antigens of LP, culture supernatants were added to MBL sepharose columns and trapped antigens eluted with increasing concentrations of EDTA (10 mM, 50 mM and 100 mM) and then desalted before being tested for ability to activate C. The EDTA eluate with highest activity was run on a polyacrylamide gel and silver stained proteins analyzed by mass spectroscopy. Results Antigens released by P. falciparum growing in culture activated C leading to C3b deposition on E. Maximal activation at 7% parasitemia was associated with schizont stage (36.7%) compared to 22% for rings, 21% for trophozoites and 3% for sham culture. All the three pathways of C were activated, with highest activation being for the alternative pathway (only 6% of C activation potential remained), 65% for classiical and 43% for the LP. Seven MBL binding merozoite proteins were identified by mass spectrometry in the 50 mM EDTA eluate. Conclusions MBL binding merozoite adhesins with ability to activate C pathway were identified. The survival advantage for such pronounced C activation is unclear, but opsonisation could facilitate recognition and invasion of E.
    PLoS ONE 08/2014; 9(8):e105093. DOI:10.1371/journal.pone.0105093 · 3.23 Impact Factor
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    • "The function of ApiAP2 proteins outside of the AP2 domain(s) itself is unclear, though the rest of the protein presumably has some involvement in facilitating protein–protein interactions. Yeast-two-hybrid studies have indicated that some P. falciparum ApiAP2 proteins interact with each other, as well as with other regulatory proteins, such as the histone acetyltransferase Gcn5 (76). Structural studies of a P. falcparum ApiAP2 (PF14_0633) demonstrate that AP2 domains can dimerize to bind DNA (56). "
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