title: A thioredoxin domain-containing protein 12 from black rockfish Sebastes schlegelii: Responses to immune challenges and protection from apoptosis against oxidative stress.
abstract: Thioredoxin (TXN) superfamily proteins are identified by the presence of a thioredoxin active site with a conserved CXXC active motif. TXN members are involved in a wide range of biochemical and biological functions including redox regulation, refolding of disulfide containing proteins, and regulation of transcription factors. In the present study, a thioredoxin domain-containing protein 12 was identified and characterized from black rockfish, Sebastes schlegelii (RfTXNDC12). The full length of RfTXNDC12 consists of a 522-bp coding region encoding a 173-amino acid protein. It has a 29-amino acid signal peptide and a single TXN active site with a consensus atypical WCGAC active motif. Multiple sequence alignment revealed that the active site is conserved among vertebrates. RfTXNDC12 shares highest identity with its Epinephelus coioides homolog. Transcriptional analysis revealed its ubiquitous expression in a wide range of tissues with the highest expression in the ovary. Immune challenges conducted with Streptococcus iniae and poly I:C caused upregulation of RfTXNDC12 transcript levels in gills and peripheral blood cells (PBCs), while lipopolysaccharide injection caused downregulation of RfTXNDC12 in gills and upregulation in PBCs. Similar to TXN, RfTXNDC12 exhibited insulin disulfide reducing activity. Interestingly, the recombinant protein showed significant protection of LNCaP cells against apoptosis induced by H2O2-mediated oxidative stress in a concentration dependent manner. Collectively, the present data indicate that RfTXNDC12 is a TXN superfamily member, which could function as a potential antioxidant enzyme and be involved in a defense mechanism against immune challenges.
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors.forename: William Shanthakumar
authors.initials: WS
authors.lastname: Thulasitha
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors.forename: Navaneethaiyer
authors.initials: N
authors.lastname: Umasuthan
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors.forename: R G P T
authors.initials: RGPT
authors.lastname: Jayasooriya
authors.affiliation: Genetics & Breeding Research Center, National Institute of Fisheries Science, Geoje 656-842, Republic of Korea.
authors.forename: Jae Koo
authors.initials: JK
authors.lastname: Noh
authors.affiliation: Graduate School of Medicine, Korea University, Ansan, Gyeonggido 425-707, Republic of Korea. Electronic address: hcpark67@korea.ac.kr.
authors.forename: Hae-Chul
authors.initials: HC
authors.lastname: Park
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea. Electronic address: jehee@jejunu.ac.kr.
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D017124:Conserved Sequence; D004220:Disulfides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D007328:Insulin / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D010473:Perciformes / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000201:enzymology / Q000473:pathology; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013879:Thioredoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D000975:Antioxidants; D004220:Disulfides; D029941:Fish Proteins; D007328:Insulin; D013879:Thioredoxins; D006861:Hydrogen Peroxide
keywords: Immune challenge; Oxidative stress; Rockfish; Thioredoxin domain containing protein 12