Molecular characterization of phospholipid hydroperoxide glutathione peroxidases from Hydra vulgaris.
Apparent full-length cDNA sequences coding respectively for mitochondrial (HvGPx41) and nuclear (HvGPx42) phospholipid hydroperoxide glutathione peroxidase were isolated from Hydra vulgaris. The cDNA sequences share total identity in their 3'-end and differ in their 5'-end. The protein-coding regions of the HvGPx41 and HvGPx42 cDNA encode polypeptides of 190 and 168 amino acids, including a TGA-encoded selenocysteine, respectively. Phylogenetic analysis showed that the HvGPx41 and HvGPx42 are clustered together along with other phospholipid hydroperoxide glutathione peroxidases (PHGPx) from several organisms. A tertiary structure model generated for the H. vulgaris PHGPx displayed the thioredoxin fold. Hydrae exposed to starvation, metal and oxidative stress responded by regulating their PHGPx mRNA transcription. These results indicated that the PHGPx gene is affected by the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure. Hence the expression of PHGPx mRNA in hydra may have potential use as molecular biomarkers for assessing stress, toxicity and pro-oxidant quality of chemicals and aquatic environmental quality.
Dash
Bhagirathi
B
Faculty of Toxicology, Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Metz
Richard
R
Huebner
Henry J
HJ
Porter
Weston
W
Phillips
Timothy D
TD
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D006829:Hydra / Q000201:enzymology*; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D012333:RNA, Messenger; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase