title: Proline modulates the Trypanosoma cruzi resistance to reactive oxygen species and drugs through a novel D, L-proline transporter.
abstract: Trypanosoma cruzi, the etiological agent of Chagas' disease, has a metabolism largely based on the consumption of glucose and proline. This amino acid is essential for host cells infection and intracellular differentiation. In this work we identified a proline transporter (TcAAAP069) by yeasts complementation assays and overexpression in Trypanosoma cruzi epimastigotes. TcAAAP069 is mono-specific for proline but presents an unusual feature; the lack of stereospecificity, because it is competitively inhibited by the D- enantiomer. Parasites overexpressing TcAAAP069 have an increased intracellular proline concentration, 2.6-fold higher than controls, as a consequence of a higher proline transport rate. Furthermore, augmented proline concentration correlates with an improved resistance to trypanocidal drugs and also to reactive oxygen species including hydrogen peroxide and nitric oxide, emulating natural physiological situations. The IC50s for nifurtimox, benznidazole, H2O2 and NO. were 125%, 68%, 44% and 112% higher than controls, respectively. Finally, proline metabolism generates a higher concentration (48%) of ATP in TcAAAP069 parasites. Since proline participates on essential energy pathways, stress and drug resistance responses, these results provide a novel target for the development of new drugs for the treatments for Chagas' disease.
authors.affiliation: Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas "Alfredo Lanari", Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
authors.forename: Melisa
authors.initials: M
authors.lastname: Sayé
authors.affiliation: Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas "Alfredo Lanari", Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
authors.forename: Mariana R
authors.initials: MR
authors.lastname: Miranda
authors.affiliation: Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas "Alfredo Lanari", Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
authors.forename: Fabio
authors.initials: F
authors.lastname: di Girolamo
authors.affiliation: Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas "Alfredo Lanari", Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
authors.forename: María
authors.initials: M
authors.lastname: de los Milagros Cámara
authors.affiliation: Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas "Alfredo Lanari", Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Pereira
mesh_terms: D026921:Amino Acid Transport Systems, Neutral / Q000378:metabolism*; D019295:Computational Biology; D004351:Drug Resistance / Q000187:drug effects*; D008018:Life Cycle Stages / Q000187:drug effects; D011392:Proline / Q000494:pharmacology*; D021381:Protein Transport / Q000187:drug effects; D015800:Protozoan Proteins / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects; D013347:Subcellular Fractions / Q000378:metabolism; D014344:Trypanocidal Agents / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects* / Q000254:growth & development
chemical_list: D026921:Amino Acid Transport Systems, Neutral; D015800:Protozoan Proteins; D017382:Reactive Oxygen Species; D014344:Trypanocidal Agents; C033082:proline transporter; D011392:Proline