Proteinases of piroplasmid bovine pathogens: comparative genomic analysis of Babesia bovis and Theileria annulata

SCHNITTGER L; MESPLET M; FLORIN-CHRISTENSEN M

Congreso; 13th International Congress of Parasitology (ICOPA); 2014

Proteinases of piroplasmid bovine pathogens: comparative genomic analysisof Babesia bovis and Theileria annulataBACKGROUND: Closely related piroplasmids B. bovis and T. annulata share agenome of similar size (8 Mb) though T. annulata features an additional schizontparasite stage. Proteolytic enzymes of pathogenic apicomplexa parasites play animportant role in the invasion into, survival in, and egress from the bovine erythrocytehost cell. Due to their vital function in the parasite life cycle, they are consideredpotential vaccine candidates and pharmacological targets.METHODS: Based on bioinformatic tools, an algorithm has been conceived allowingpredicting and comparing putative proteinases in the genomes of the bovinepiroplasmid pathogens B. bovis and T. annulata.RESULTS: The repertoire of proteinases is of similar size in both piroplasmidspecies. All in all, 129 proteases were identified in the genome of B. bovis and 126 inthat of T. annulata. Orthology between proteinases could be determined for 97genes. A detailed analysis showed a similar number of peptidases of the aspartic,metallo, and threonine type. In contrast, a considerable higher number of cysteinepeptidases were found to be present in T. annulata (34 of which 13 are speciesspecific)compared to B. bovis (22 of which 1 is species-specific) while serineproteinases are more frequent in B. bovis (50 of which 23 species-specificproteinases) with respect to T. annulata (36 of which 9 are species-specific).CONCLUSIONS: Observed differences are mainly due to successive duplicationevents of members of the proteinase families C1 and S54. It is hypothesized thatobserved degradome disparities correspond to life cycle particularities between T.annulata and B. bovis.Financed by CONICET, INTA (PNBIO-1131034), and the European Commission(INCO 245145, PIROVAC)