LAUSR

Schistosoma mansoni depends upon the purine salvage pathway to obtain purine nucleotides; therefore, enzymes from this pathway are essential for parasite survival. Here, we focused on the adenine phosphoribosyltransferase (APRT) enzyme, which catalyzes the condensation reaction between adenine and PRPP (5-phosphoribosylpyrophosphate) to produce AMP and PPi. Kinetic experiments using the heterologously expressed protein of one APRT isoform from S. mansoni indicate that it is catalytically active, and whole-mount in situ hybridization studies indicate that the transcripts of this protein are concentrated in the posterior region of the ovary and vitellaria of female adult worms. Moreover, a phylogenetic analysis has shown that APRT exists in multiple copies originating from gene duplications at the base of the Schistosoma genus. Other enzymes from the purine and pyrimidine salvage pathways have also been found to present multiple copies in schistosomes, suggesting that evolutionary pressure to diversify these genes' families may be related to a specialized role in parasite reproduction.