title: Plasmodium interspersed repeats: the major multigene superfamily of malaria parasites.
abstract: Functionally related homologues of known genes can be difficult to identify in divergent species. In this paper, we show how multi-character analysis can be used to elucidate the relationships among divergent members of gene superfamilies. We used probabilistic modelling in conjunction with protein structural predictions and gene-structure analyses on a whole-genome scale to find gene homologies that are missed by conventional similarity-search strategies and identified a variant gene superfamily in six species of malaria (Plasmodium interspersed repeats, pir). The superfamily includes rif in P.falciparum, vir in P.vivax, a novel family kir in P.knowlesi and the cir/bir/yir family in three rodent malarias. Our data indicate that this is the major multi-gene family in malaria parasites. Protein localization of products from pir members to the infected erythrocyte membrane in the rodent malaria parasite P.chabaudi, demonstrates phenotypic similarity to the products of pir in other malaria species. The results give critical insight into the evolutionary adaptation of malaria parasites to their host and provide important data for comparative immunology between malaria parasites obtained from laboratory models and their human counterparts.
authors.affiliation: Institute of Biomedical and Life Sciences, Division of Infection and Immunity, IBLS, University of Glasgow, Glasgow G12 8QQ, UK. c.janssen@bio.gla.ac.uk
authors.forename: Christoph S
authors.initials: CS
authors.lastname: Janssen
authors.forename: R Stephen
authors.initials: RS
authors.lastname: Phillips
authors.forename: C Michael R
authors.initials: CM
authors.lastname: Turner
authors.forename: Michael P
authors.initials: MP
authors.lastname: Barrett
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D017125:Genes, Protozoan; D023281:Genomics; D006801:Humans; D020071:Interspersed Repetitive Sequences; D008288:Malaria / Q000469:parasitology; D005810:Multigene Family; D010802:Phylogeny; D010961:Plasmodium / Q000235:genetics*; D015800:Protozoan Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics
chemical_list: D015800:Protozoan Proteins