Two novel phospholipid hydroperoxide glutathione peroxidase genes ofParagonimus westermaniinduced by oxidative stress

Abstract

Phospholipid hydroperoxide glutathione peroxidase (PHGPx; GPx4) plays unique roles in the protection of cells against oxidative stress by catalysing reduction of lipid hydroperoxides. We characterized 2 novel GPx genes from a lung fluke, Paragonimus westermani (designated PwGPx1 and PwGPx2). These single copy genes spanned 6559 and 12 371 bp, respectively, and contained each of 5 intervening introns. The PwGPx2 harboured a codon for Sec and a Sec insertion sequence motif. Proteins encoded by the Paragonimus genes demonstrated a primary structure characteristic to the PHGPx family, including preservation of catalytic and glutathione-binding domains and absence of the subunit interaction domain. Expression of PwGPx1 increased gradually as the parasite matured, whereas that of PwGPx2 was temporally regulated. PwGPx2 was expressed at the basal level from the metacercariae to the 3-week-old juveniles; however, the expression was significantly induced in the 7-week-old immature worms and reached a plateau in the 12-week-old adults and eggs. PwGPx1 and PwGPx2 were largely localized in vitellocytes within vitelline glands and eggs. Oxidative stress-inducible paraquat, juglone and H2O2 substantially augmented the PwGPx1 and PwGPx2 expressions in viable worms by 1.5- to 11-fold. Our results strongly suggested that PwGPxs may actively participate in detoxification of oxidative hazards in P. westermani.

Molecular cloning and characterization of a phospholipid hydroperoxide glutathione peroxidase gene from a blood fluke Schistosoma japonicum

“…westermani parasites, were also found localised in vitellocytes within vitelline follicles and premature eggs [20,21]. In the present study, our RT-PCR and western blotting results showed that the S. japonicum GPx expression was found to be confined exclusively to the adult female worms and eggs (Fig.…”

“…Clonorchis sinensis [20] and Paragonimus westermani [21] Observations regarding the tissue distribution of the C. sinensis, P. westermani and S. mansoni PHGPxs were shown to be largely localized in vitellocytes within vitelline follicles and eggs [20][21][22].…”

“…at 37 o C. The worms were transferred into fresh media containing methyl viologen dichloride hydrate (paraquat, 10/50 mM) or H 2 O 2 (0.2/1.0 mM) and incubated for 2 h at 37 o C[20,21].The worms were washed more than 10 times with cold physiological saline at 4 o C. Soluble proteins were prepared from each of the experimental groups, as described above. Incubation with medium only was used as a control.…”

Expression and characterization of a phospholipid hydroperoxide glutathione peroxidase gene inSchistosoma japonicum

“…2008) and two GPx proteins in P. westermani (Kim et al . 2009), showing strong phylogenetic affinities towards the vertebrate PHGPx, have been described. In the present study, we isolated and characterized a novel PHGPx gene from a blood fluke S. japonicum .…”

“…2008) and Paragonimus westermani (Kim et al . 2009). Observations regarding the tissue distribution of the S. mansoni, C. sinensis and P. westermani PHGPxs were shown to be largely localized in vitellocytes within vitelline follicles and eggs (Roche et al .…”