title: Expression profiles of selenium dependent glutathione peroxidase and glutathione S-transferase from Exopalaemon carinicauda in response to Vibrio anguillarum and WSSV challenge.
abstract: A selenium-dependent glutathione peroxidase cDNA was obtained from the ridgetail white prawn Exopalaemon carinicauda (EcGPx) by rapid amplification of cDNA ends (RACE) methods. The full-length cDNA of EcGPx was 946 bp, which contains a 5'-untranslated region (UTR) of 105 bp, 3'-UTR of 280 bp with a poly (A) tail, an open reading frame (ORF) of 561 bp, encoding a 186 amino-acid polypeptide with the predicted molecular weight of 21.35 kDa and estimated isoelectric point of 7.65. It involves a putative selenocysteine (U39) residue which is encoded by an opal codon, (220)TGA(222), and forms an active site with residues Q73 and W141. Sequence analysis revealed that a GPx signature motif 2 ((63)LAFPCNQF(70)), an extra active site motif ((151)WNFEKF(156)), two putative N-glycosylation site ((75)NNT(77) and (107)NGS(109)), and two arginine residues (R89 and R167) were observed in the EcGPx sequence. Comparison of amino acid sequences showed that white shrimp GPx is more closely related to GPx1 and GPx2 subgroups. Quantitative real-time RT-PCR analysis indicated that two glutathione antioxidant enzymes of E. carinicauda, glutathione peroxidase (designated EcGPx) and glutathione S-transferase (designated EcGST) were widely expressed in all the tested tissues, but showed different expression patterns. After Vibrio anguillarum and WSSV challenge, EcGPx and EcGST transcripts both in hemocytes and hepatopancreas increased in the first 6 h and 3 h, respectively. The results suggested that EcGPx and EcGST might be associated with the immune defenses to V. anguillarum and WSSV in E. carinicauda.
authors.affiliation: Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao 266071, PR China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Duan
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Jitao
authors.initials: J
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
mesh_terms: D000818:Animals; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D033541:Palaemonidae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D014733:Vibrio / Q000502:physiology*; D046848:White spot syndrome virus 1 / Q000502:physiology*
chemical_list: D005979:Glutathione Peroxidase; C080439:selenium-independent glutathione peroxidase
keywords: Exopalaemon carinicauda; Expression; Gene cloning; Glutathione S-transferases (GST); Glutathione peroxidase (GPx)