Trypanosoma cruzi: A putative vacuolar ATP synthase subunit and a CAAX prenyl protease-encoding gene, as examples of gene identification in genome projects

An international genome program has been initiated to increase the knowledg e about the Trypanosoma cruzi genome and thereby find effective tools to tr eat Chagas' disease. We here report the molecular characterization of two n ovel genes found in the course of this project. Two of the open reading fra mes (ORF) identified in the sequencing of the third smallest chromosome of the CL Brener strain of T. cruzi were selected for further molecular charac terization due to their similarity to genes with interesting functions in o ther organisms and their potential as targets to combat the parasite. The f irst ORF (402 bp) showed homology to a 14-kDa vacuolar ATP synthase subunit F from a variety of organisms, such as yeast, rat, bovine, human, and a nu mber of prokaryotes. The second ORF (1188 bp) resembled a CAAX prenyl prote ase-encoding gent, identified in different organisms, including Homo sapien s, Saccharomyces cerevisiae, and Arabidopsis thaliana, as well as several p rokaryotes. RT-PCR from T. cruzi total epimastigote RNA allowed us to isola te the complete transcripts: of these genes. Furthermore, screening of an a vailable normalized cDNA library derived from the same stage of the parasit e confirmed that both genes are expressed at least in the epimastigote stag e of T. cruzi. Comparison of the putative T. cruzi proteins to their counte rparts in other organisms revealed significant protein sequence conservatio n over large evolutionary distances. Computer analysis revealed the presenc e of several motifs in both proteins, possibly related to the regulation an d localization of these proteins in the parasite. (C) 2000 Academic Press.