Cytosolic glutathione S-transferases of Oesophagostomum dentatum.
Oesophagostomum dentatum stages were investigated for glutathione S-transferase (GST) expression at the protein and mRNA levels. GST activity was detected in all stages (infectious and parasitic stages including third- and fourth-stage larvae of different ages as well as males and females) and could be dose-dependently inhibited with sulfobromophthalein (SBP). Addition of SBP to in vitro larval cultures reversibly inhibited development from third- to fourth-stage larvae. Two glutathione-affinity purified proteins (23 and 25 kDa) were detected in lysates of exsheathed third-stage larvae by SDS-PAGE. PCR-primers were designed based on peptide sequences and conserved GST sequences of other nematodes for complete cDNA sequences (621 and 624 nt) of 2 isoforms, Od-GST1 and Od-GST2, with 72% nucleotide similarity and 75% for the deduced proteins. Genomic sequences consisted of 7 exons and 6 introns spanning 1296 bp for Od-GST1 and 1579 and 1606 bp for Od-GST2. Quantitative real-time-PCR revealed considerably elevated levels of Od-GST1 in the early parasitic stages and slightly reduced levels of Od-GST2 in male worms. Both Od-GSTs were most similar to GST of Ancylostoma caninum (nucleotides: 73 and 70%; amino acids: 80 and 73%). The first three exons (75 amino acids) corresponded to a synthetic prostaglandin D2 synthase (53% similarity). O. dentatum GSTs might be involved in intrinsic metabolic pathways which could play a role both in nematode physiology and in host-parasite interactions.
Joachim
A
A
Institute of Parasitology and Zoology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, A-1210 Vienna, Austria. Anja.Joachim@vu-wien.ac.at
Ruttkowski
B
B
D000818:Animals; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D015870:Gene Expression; D005982:Glutathione Transferase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D007814:Larva / Q000201:enzymology; D008297:Male; D009815:Oesophagostomum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D018076:DNA, Complementary; D007527:Isoenzymes; D005982:Glutathione Transferase