title: A thioredoxin with antioxidant activity identified from Eriocheir sinensis.
abstract: Thioredoxin, with a redox-active disulfide/dithiol in the active site, is the major ubiquitous disulfide reductase responsible for maintaining proteins in their reduced state. In the present study, the cDNA encoding thioredoxin-1 (designated EsTrx1) was cloned from Chinese mitten crab Eriocheir sinensis by using rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of EsTrx1 was of 641 bp, containing a 5' untranslated region (UTR) of 17 bp, a 3' UTR of 306 bp with a poly (A) tail, and an open reading frame (ORF) of 318 bp encoding a polypeptide of 105 amino acids. The high similarity of EsTrx1 with Trx1s from other animals indicated that EsTrx1 should be a new member of the Trx1 sub-family. Quantitative real-time PCR analysis revealed the presence of EsTrx1 transcripts in gill, gonad, hepatopancreas, muscle, heart and haemocytes. The expression of EsTrx1 mRNA in haemocytes was up-regulated after Listonella anguillarum challenge, reached the maximum level at 6h post-stimulation, and then dropped back to the original level gradually. In order to elucidate its biological functions, EsTrx1 was recombined and expressed in E. coli BL21 (DE3). The rEsTrx1 was demonstrated to possess the expected redox activity in enzymatic analysis, and to be more potent than GSH in antioxidant capacity. These results together indicated that EsTrx1 could function as an important antioxidant in a physiological context, and perhaps is involved in the responses to bacterial challenge.
authors.affiliation: The Key laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Changkao
authors.initials: C
authors.lastname: Mu
authors.forename: Jianmin
authors.initials: J
authors.lastname: Zhao
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Song
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.forename: Limei
authors.initials: L
authors.lastname: Qiu
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Gai
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Cui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000378:metabolism* / Q000382:microbiology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007328:Insulin / Q000378:metabolism; D053526:Listonella / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D013879:Thioredoxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000975:Antioxidants; D018076:DNA, Complementary; D007328:Insulin; D011994:Recombinant Proteins; D013879:Thioredoxins