title: Phylogenomic analyses of malaria parasites and evolution of their exported proteins.
abstract: BACKGROUND
  Plasmodium falciparum is the most malignant agent of human malaria. It belongs to the taxon Laverania, which includes other ape-infecting Plasmodium species. The origin of the Laverania is still debated. P. falciparum exports pathogenicity-related proteins into the host cell using the Plasmodium export element (PEXEL). Predictions based on the presence of a PEXEL motif suggest that more than 300 proteins are exported by P. falciparum, while there are many fewer exported proteins in non-Laverania.
  
  
  RESULTS
  A whole-genome approach was applied to resolve the phylogeny of eight Plasmodium species and four outgroup taxa. By using 218 orthologous proteins we received unanimous support for a sister group position of Laverania and avian malaria parasites. This observation was corroborated by the analyses of 28 exported proteins with orthologs present in all Plasmodium species. Most interestingly, several deviations from the P. falciparum PEXEL motif were found to be present in the orthologous sequences of non-Laverania.
  
  
  CONCLUSIONS
  Our phylogenomic analyses strongly support the hypotheses that the Laverania have been founded by a single Plasmodium species switching from birds to African great apes or vice versa. The deviations from the canonical PEXEL motif in orthologs may explain the comparably low number of exported proteins that have been predicted in non-Laverania.
authors.affiliation: Institute of Zoology and Zoological Museum, University of Hamburg, Martin-Luther-King-Platz 3, D-20146 Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Pick
authors.forename: Ingo
authors.initials: I
authors.lastname: Ebersberger
authors.forename: Tobias
authors.initials: T
authors.lastname: Spielmann
authors.forename: Iris
authors.initials: I
authors.lastname: Bruchhaus
authors.forename: Thorsten
authors.initials: T
authors.lastname: Burmester
mesh_terms: D020816:Amino Acid Motifs; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D006801:Humans; D008288:Malaria / Q000469:parasitology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010961:Plasmodium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D021381:Protein Transport; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism*; D055571:Secretory Pathway; D016415:Sequence Alignment
chemical_list: D001427:Bacterial Toxins; D015800:Protozoan Proteins