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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Proline Dehydrogenase Regulates Redox State and Respiratory Metabolism in Trypanosoma cruzi

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Author(s):
Paes, Lisvane Silva [1] ; Mantilla, Brian Suarez [1] ; Zimbres, Flavia Menezes [1] ; Furusho Pral, Elisabeth Mieko [1] ; de Melo, Patricia Diogo [2] ; Tahara, Erich B. [3] ; Kowaltowski, Alicia J. [3] ; Elias, Maria Carolina [2] ; Silber, Ariel Mariano [1]
Total Authors: 9
Affiliation:
[1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Parasitol, BR-05508 Sao Paulo - Brazil
[2] Inst Butantan, Ctr Appl Toxinol CAT CEPID, LETA, Sao Paulo - Brazil
[3] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-01498 Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: PLoS One; v. 8, n. 7 JUL 22 2013.
Web of Science Citations: 29
Abstract

Over the past three decades, L-proline has become recognized as an important metabolite for trypanosomatids. It is involved in a number of key processes, including energy metabolism, resistance to oxidative and nutritional stress and osmoregulation. In addition, this amino acid supports critical parasite life cycle processes by acting as an energy source, thus enabling host-cell invasion by the parasite and subsequent parasite differentiation. In this paper, we demonstrate that L-proline is oxidized to D 1-pyrroline-5-carboxylate (P5C) by the enzyme proline dehydrogenase (TcPRODH, E. C. 1.5.99.8) localized in Trypanosoma cruzi mitochondria. When expressed in its active form in Escherichia coli, TcPRODH exhibits a K-m of 16.58 +/- 1.69 mu M and a V-max of 66 +/- 2 nmol/min mg. Furthermore, we demonstrate that TcPRODH is a FAD-dependent dimeric state protein. TcPRODH mRNA and protein expression are strongly upregulated in the intracellular epimastigote, a stage which requires an external supply of proline. In addition, when Saccharomyces cerevisiae null mutants for this gene (PUT1) were complemented with the TcPRODH gene, diminished free intracellular proline levels and an enhanced sensitivity to oxidative stress in comparison to the null mutant were observed, supporting the hypothesis that free proline accumulation constitutes a defense against oxidative imbalance. Finally, we show that proline oxidation increases cytochrome c oxidase activity in mitochondrial vesicles. Overall, these results demonstrate that TcPRODH is involved in proline-dependant cytoprotection during periods of oxidative imbalance and also shed light on the participation of proline in energy metabolism, which drives critical processes of the T. cruzi life cycle. (AU)