title: Thioredoxin of golden pompano involved in the immune response to Photobacterium damselae.
abstract: Thioredoxin (TRX) is one of the key systems responsible for keeping the intracellular environment in a highly reduced state. In this study, a full-length TRX cDNA sequence (ToTRX) from golden pompano Trachinotus ovatus was identified after pyrosequencing of golden pompano cDNA library. ToTRX cDNA is comprised of 786 bp, and contained a 324 bp open reading frame (ORF) encoding a 107 amino acid polypeptide, a 5' untranslated region (UTR) of 116 bp, and a long 3'- UTR of 346 bp. Multiple sequence alignment revealed that ToTRX contained the highly conserved redox active disulphide/dithiol site (CGPC) of the thioredoxin active family, and phylogenetic tree showed that ToTRX had a closer evolution relationship with TRX from Oplegnathus fasciatus and Anoplopoma fimbria. ToTRX mRNA is ubiquitously expressed in all detected tissues with the higher expression levels in the stomach, gill and fin tissues. The expression of ToTRX mRNA was significantly up-regulated in liver, kidney, intestine and spleen of golden pompano injected with Photobacterium damselae. The recombinant ToTRX protein (rToTRX) was expressed in Escherichia coli BL21 (DE3), and then purified and refolded. The insulin disulfides assay was performed to investigate the enzymatic oxidoreductase activity of rToTRX, and the results demonstrated that rToTRX exhibited a high reducing activity in presence of DTT, while no activity was observed in the regroup without DTT and blank control group. Over all, the study provided the useful information to help further understand the functional mechanism of TRX in marine fish immunity.
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, PR China.
authors.forename: Long
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China.
authors.forename: Huayang
authors.initials: H
authors.lastname: Guo
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China.
authors.forename: Shigui
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China. Electronic address: zhangdch@163.com.
authors.forename: Dianchang
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010473:Perciformes; D010776:Photobacterium / Q000502:physiology*; D010802:Phylogeny; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D013879:Thioredoxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D013879:Thioredoxins
keywords: Antioxidant function; Immune response; Thioredoxin; Trachinotus ovatus; mRNA expression