Polyamine metabolism in Trypanosoma cruzi: studies on the expression and regulation of heterologous genes involved in polyamine biosynthesis

Algranati, Israel D.

doi:10.1007/s00726-009-0425-6

Cited by 14 publications

(6 citation statements)

References 46 publications

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“…Unfortunately, there is limited information regarding the rate of Spd synthesis from Put (Fig. 1), although it appears to be fast [69]; spermidine synthase (SpdS) from T. cruzi has not been characterized. This additional internal source of Spd may further decrease the control exerted by SpdT.…”

Section: Discussionmentioning

confidence: 99%

Drug target validation of the trypanothione pathway enzymes through metabolic modelling

et al. 2012

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A kinetic model of trypanothione [T(SH) 2 ] metabolism in Trypanosoma cruzi was constructed based on enzyme kinetic parameters determined under near-physiological conditions (including glutathione synthetase), and the enzyme activities, metabolite concentrations and fluxes determined in the parasite under control and oxidizing conditions. The pathway structure is characterized by a T(SH) 2 synthetic module of low flux and low catalytic capacity, and another more catalytically efficient T(SH) 2 -dependent antioxidant ⁄ regenerating module. The model allowed quantification of the contribution of each enzyme to the control of T(SH) 2 synthesis and concentration (flux control and concentration control coefficients, respectively). The main control of flux was exerted by c-glutamylcysteine synthetase (cECS) and trypanothione synthetase (TryS) (control coefficients of 0.58-0.7 and 0.49-0.58, respectively), followed by spermidine transport (0.24); negligible flux controls by trypantothione reductase (TryR) and the T(SH) 2 -dependent antioxidant machinery were determined. The concentration of reduced T(SH) 2 was controlled by TryR (0.98) and oxidative stress ()0.99); however, cECS and TryS also exerted control on the cellular level of T(SH 2 ) when they were inhibited by more than 70%. The model predicted that in order to diminish the T(SH) 2 synthesis flux by 50%, it is necessary to inhibit cECS or TryS by 58 or 63%, respectively, or both by 50%, whereas more than 98% inhibition was required for TryR. Hence, simultaneous and moderate inhibition of cECS and TryS appears to be a promising multi-target therapeutic strategy. In contrast, use of highly potent and specific inhibitors for TryR and the antioxidant machinery is necessary to affect the antioxidant capabilities of the parasites. DatabaseThe glutathione synthetase gene sequences from the Ninoa and Queretaro strains have been submitted to the GenBank database under accession numbers HQ398240 and HQ398239, respectively Abbreviations

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Section: Discussionmentioning

confidence: 99%

Drug target validation of the trypanothione pathway enzymes through metabolic modelling

et al. 2012

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“…6; Fuell et al, 2010). Interestingly, the protozoa Trypanosoma cruzi lacks ODC activity and cannot grow in a medium without putrescine (Algranati, 2010).…”

Section: Evolution Of Plant Ldc For the Production Of Alkaloidsmentioning

confidence: 99%

Molecular Evolution and Functional Characterization of a Bifunctional Decarboxylase Involved in Lycopodium Alkaloid Biosynthesis

et al. 2016

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Lycopodium alkaloids (LAs) are derived from lysine (Lys) and are found mainly in Huperziaceae and Lycopodiaceae. LAs are potentially useful against Alzheimer's disease, schizophrenia, and myasthenia gravis. Here, we cloned the bifunctional lysine/ornithine decarboxylase (L/ODC), the first gene involved in LA biosynthesis, from the LA-producing plants Lycopodium clavatum and Huperzia serrata. We describe the in vitro and in vivo functional characterization of the L. clavatum L/ODC (LcL/ODC). The recombinant LcL/ODC preferentially catalyzed the decarboxylation of L-Lys over L-ornithine (L-Orn) by about 5 times. Transient expression of LcL/ODC fused with the amino or carboxyl terminus of green fluorescent protein, in onion (Allium cepa) epidermal cells and Nicotiana benthamiana leaves, showed LcL/ODC localization in the cytosol. Transgenic tobacco (Nicotiana tabacum) hairy roots and Arabidopsis (Arabidopsis thaliana) plants expressing LcL/ODC enhanced the production of a Lys-derived alkaloid, anabasine, and cadaverine, respectively, thus, confirming the function of LcL/ODC in plants. In addition, we present an example of the convergent evolution of plant Lys decarboxylase that resulted in the production of Lys-derived alkaloids in Leguminosae (legumes) and Lycopodiaceae (clubmosses). This convergent evolution event probably occurred via the promiscuous functions of the ancestral Orn decarboxylase, which is an enzyme involved in the primary metabolism of polyamine. The positive selection sites were detected by statistical analyses using phylogenetic trees and were confirmed by site-directed mutagenesis, suggesting the importance of those sites in granting the promiscuous function to Lys decarboxylase while retaining the ancestral Orn decarboxylase function. This study contributes to a better understanding of LA biosynthesis and the molecular evolution of plant Lys decarboxylase.

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“…Several studies related to polyamine metabolism in pathogenic protozoa have been carried out with the aim to affect the proliferation, infectivity, or differentiation of these organisms and find new therapeutic targets against parasitic diseases [1, 14, 15]. With this kind of approach it was discovered that the acute infections of Trypanosoma brucei brucei in mice as well as the human African sleeping sickness, caused by T. brucei gambiense , can be treated by α -difluoromethylornithine (DFMO), the specific and irreversible ornithine decarboxylase (ODC) inhibitor [16–18].…”

Section: Introductionmentioning

confidence: 99%

Trypanosoma cruzi Coexpressing Ornithine Decarboxylase and Green Fluorescence Proteins as a Tool to Study the Role of Polyamines in Chagas Disease Pathology

et al. 2011

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Polyamines are essential for Trypanosoma cruzi, the causative agent of Chagas disease. As T. cruzi behaves as a natural auxotrophic organism, it relies on host polyamines biosynthesis. In this paper we obtained a double-transfected T. cruzi parasite that expresses the green fluorescent protein (GFP) and a heterologous ornithine decarboxylase (ODC), used itself as a novel selectable marker. These autotrophic and fluorescent parasites were characterized; the ODC presented an apparent Km for ornithine of 0.51 ± 0.16 mM and an estimated Vmax value of 476.2 nmoles/h/mg of protein. These expressing ODC parasites showed higher metacyclogenesis capacity than the auxotrophic counterpart, supporting the idea that polyamines are engaged in this process. This double-transfected T. cruzi parasite results in a powerful tool—easy to follow by its fluorescence—to study the role of polyamines in Chagas disease pathology and in related processes such as parasite survival, invasion, proliferation, metacyclogenesis, and tissue spreading.

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Polyamine metabolism in Trypanosoma cruzi: studies on the expression and regulation of heterologous genes involved in polyamine biosynthesis

Cited by 14 publications

References 46 publications

Drug target validation of the trypanothione pathway enzymes through metabolic modelling

Drug target validation of the trypanothione pathway enzymes through metabolic modelling

Molecular Evolution and Functional Characterization of a Bifunctional Decarboxylase Involved in Lycopodium Alkaloid Biosynthesis

Trypanosoma cruzi Coexpressing Ornithine Decarboxylase and Green Fluorescence Proteins as a Tool to Study the Role of Polyamines in Chagas Disease Pathology

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