Molecular Cloning and Characterization of a 2-Cys Peroxiredoxin From Taenia Solium

Abstract

A Taenia solium 2-Cys peroxiredoxin (Ts2-CysPrx) clone was isolated from a T. solium adult cDNA library. The clone encodes a polypeptide comprising 197 amino acids with a predictive Mr = 21,836. It has the 2 classical cysteine domains from the typical 2-Cys peroxiredoxins, and its primary amino acid sequence shows higher identity with 2 Echinococcus 2-Cys peroxiredoxins. Northern and Southern blot hybridizations exhibit an mRNA with a size of -1.0 kb, encoded by 1 gene. Ts2-CysPrx was expressed in Escherichia coli and purified by anion-exchange chromatography. Biochemical analysis showed Ts2-CysPrx is a dimer composed by monomers of -22 kDa that presented activity with hydrogen peroxide (H2O2) and cumene hydroperoxide. It presented the catalytic mechanism for a typical 2-CysPrx because the homodimeric oxidized form is reduced to a monomeric form by thioredoxin (Trx) and by dithiothreitol (DTT) and was converted to a homodimeric oxidized form by H2O2. Western blot studies using antibodies against Ts2-CysPrx revealed that the protein is expressed during the entire T. solium life cycle, as in other Taenia species. Immunohistochemical studies indicated that Ts2-CysPrx is localized on the tegument and in tegumentary and muscle cells of cysticerci. We also show that T. crassiceps cysticerci can tolerate H2O2 levels of 2.5 mM for 2.5 hr.

Characterization of one typical 2-Cys Peroxiredoxin gene of Taenia solium and Taenia crassiceps

“…Lack of induction of Tc2-CysPrx suggests that this protein could be an antioxidant housekeeping gene for endogenous H 2 O 2 that possibly participates as a redox regulator, rather than a responsive gene against exogenous oxidative stress. This is in accordance with our previous observations made in Ts2-CysPrx, where gene expression persists through all the life cycle of T. solium, even in the adult stage which is not subject to oxidative stress (Molina-López et al 2006). It is likely that other non-enzymatic antioxidant systems could act to protect the parasite, as seen in S. mansoni, where oxidant conditions induce albumin silent gene expression as a sacrificial protein prone to oxidation (Sayed et al 2006).…”

“…In this context, reports on S. mansoni and S. japonicum show that there are three typical 2-Cys Prxs isoforms in schistosomatids: a cytosolic overoxidation insensitive Prx1, which is overexpressed under oxidant conditions and which could participate in responsive antioxidant defense against exogenous H 2 O 2 ; and a cytosolic Prx2 and a peptide-targeted mitochondrial Prx3, which are both housekeeping genes. The latter two are prone to overoxidation by the presence of a C-terminal overoxidation FM motif, which is similar to the YF motif of the Taenia genes studied (Sayed and Williams 2004;Molina-López et al 2006). The absence of a mitochondrial signal peptide and the presence of the C-terminal YF motif suggest that Ts2-CysPrx and Tc2-CysPrx are cytosolic overoxidation susceptible Prxs, such as schistosomal Prx2.…”

“…The lack of catalase and the fact that no high H 2 O 2 -reducing activity glutathione peroxidase has been found in the Platyhelminthes phylum (Callahan et al 1988;Mei and LoVerde 1997) highlight the biological role of typical 2-Cys Prx as a major source of H 2 O 2 detoxification in these parasites (Pérez-Torres et al 2002;Lu et al 1998). Moreover, the localization of T. solium 2-Cys Prxs on the parasite tegument suggests that they are in direct contact with the host immune response (Molina-López et al 2006).…”

Cloning and characterization of thioredoxin peroxidases from Trichinella spiralis

“…TPXs are abundant in worms, and were identified in Dirofilaria immitis (Chandrashekar et al, 2000), Taenia solium (Molina-López et al, 2006), Schistosoma japonicum (Kumagai et al, 2009), S. mansoni (Vermeire and Yoshino, 2007) and other important helminth parasites (Henkle-Dührsen and Kampkötter, 2001). Here, three members of the TPX family from T. spiralis muscle larvae were characterized by AhpC-TSA domain and 1-cys Prx C domains, and reduced H 2 O 2 in vitro.…”

Peroxiredoxins in Parasites

“…Taenia solium and Taenia crassiceps have high H 2 O 2 tolerance, and constitutively express Prx1a (252). Antibodies against TsPrx1a were used to show its presence throughout development, as well as the presence of homologs in T. crassiceps cysticerci and Taenia saginata adults (170). Recombinant TsPrx1a was found to have Trx-dependent peroxidase activity with H 2 O 2 and cumene-OOH (170).…”