title: Characterization and transcriptional regulation of thioredoxin reductase 1 on exposure to oxidative stress inducing environmental pollutants in Chironomus riparius.
abstract: We characterized thioredoxin reductase 1 (TrxR1) from Chironomus riparius (CrTrxR1) and studied its expression under oxidative stress. The full-length cDNA is 1820bp long and contains an open reading frame (ORF) of 1488bp. The deduced CrTrxR1 protein has 495 amino acids and a calculated molecular mass of 54.41kDa and an isoelectric point of 6.15. There was a 71bp 5' and a 261bp 3' untranslated region with a polyadenylation signal site (AATAAA). Homologous alignments showed the presence of conserved catalytic domain Cys-Val-Asn-Val-Gly-Cys (CVNVGC), the C-terminal amino acids 'CCS' and conserved amino acids required in catalysis. The expression of CrTrxR1 is measured using quantitative real-time PCR after exposure to 50 and 100mg/L of paraquat (PQ) and 2, 10 and 20mg/L of cadmium chloride (Cd). CrTrxR1 mRNA was upregulated after PQ exposure at all conditions tested. The highest level of CrTrxR1 expression was observed after exposure to 10mg/L of Cd for 24h followed by 20mg/L for 48h. Significant downregulation of CrTrxR1 was observed after exposure to 10 and 20mg/L of Cd for 72h. This study shows that the CrTrxR1 could be potentially used as a biomarker of oxidative stress inducing environmental contaminants.
authors: School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea.
authors: Prakash M Gopalakrishnan
authors: PM
authors: Nair
authors: Jinhee
authors: J
authors: Choi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019256:Cadmium Chloride / Q000633:toxicity*; D002683:Chironomidae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D017124:Conserved Sequence; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D010269:Paraquat / Q000633:toxicity*; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D054481:Thioredoxin Reductase 1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D019476:Insect Proteins; D054481:Thioredoxin Reductase 1; D019256:Cadmium Chloride; D010269:Paraquat