title: First report of two thioredoxin homologues in crustaceans: molecular characterization, genomic organization and expression pattern in swimming crab Portunus trituberculatus.
abstract: Previously, we had reported two homologues of the thioredoxin (Trx) super-family (PtTrx1 and PtTrx2) identified from eyestalk and haemocytes cDNA library of swimming crab Portunus trituberculatus, respectively. It was the first report of two thioredoxin homologues from the same crustacean species. Here, we focused on the molecular characterization, genomic organization and expression pattern of PtTrx1 and PtTrx2. The full-length cDNA sequences of PtTrx1 and PtTrx2 were 739 and 1300 bp, encoding 105 and 133 amino acids, respectively. They both had a conserved CGPC active site and highly similar tertiary structures, which containing four β-sheets and four α-helixes. Specifically, PtTrx2 was encoded by a nuclear gene and its cellular localization was targeted to mitochondria by an N-terminal mitochondrial pre-sequence. Sequence analysis revealed PtTrx1 and PtTrx2 were encoded by different genomic locus. As the first analyzed genomic structure of PtTrxs in crustaceans, two introns with microsatellites were found in the open reading frame region of these genes. Quantitative real-time PCR analysis revealed the mRNA expression of PtTrx1 transcripts were mainly detected in gill, while, PtTrx2 in eyestalk and gill. The temporal expression levels of PtTrxs transcripts in haemocytes showed different expression patterns after challenge with Vibrio alginolyticus, Micrococcus luteus and Pichia pastoris. These results together indicate that PtTrxs should be involved in the responses to pathogen challenge of P. trituberculatus.
authors.affiliation: EMBL, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Chengwen
authors.initials: C
authors.lastname: Song
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Cui
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Shuangyan
authors.initials: S
authors.lastname: Wang
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000662:veterinary; D016982:Micrococcus luteus / Q000502:physiology; D008969:Molecular Sequence Data; D010843:Pichia / Q000502:physiology; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary; D013879:Thioredoxins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D014018:Tissue Distribution; D044149:Vibrio alginolyticus / Q000502:physiology
chemical_list: D060829:Arthropod Proteins; D018076:DNA, Complementary; D012333:RNA, Messenger; D013879:Thioredoxins