title: Genomic structure, characterization and expression analysis of a manganese superoxide dismutase from pearl oyster Pinctada fucata.
abstract: Manganese superoxide dismutase (MnSOD) is a major component of the cellular defense mechanisms against oxidative damage. We cloned and analyzed the expression pattern and genomic structure of the MnSOD gene of pearl oyster Pinctada fucata, hereafter designated as PoMnSOD. The full-length PoMnSOD cDNA was 1080 bp in length and consisted of a 5'-untranslated region (UTR) of 222 bp, a 3'-UTR of 318 bp with a polyadenylation signal (AATAAA) at 15 nucleotides upstream of the poly (A) tail, and an open reading frame (ORF) of 540 bp encoding a polypeptide of 180 amino acids with an estimated molecular mass of 20.4 kDa and a predicted pI of 6.72. Sequence analysis showed that PoMnSOD contained MnSOD family signatures F(44)NGGGHLNH(52), I(97)QGSGWGWLA(106) and D(138)VWEHAYY(145), four conserved residues for manganese metal binding (H(4), H(52), D(138) and H(142)), and two potential N-glycosylation sites (N(33) and N(51)). Homology analysis revealed that PoMnSOD shared 47.6-55.9% identity and 57.4-65.6% similarity to the other known PoMnSOD amino acid sequences. PoMnSOD genomic DNA was 5040 bp in length and contained three exons and two introns, which was a tripartite organization and coincided with the consensus GT-AG splicing rule. PoMnSOD promoter contained the various transcription factors associated with the immune modulation and stress responses. Quantitative RT-PCR analysis demonstrated that PoMnSOD was constitutively expressed in all detected tissues, and PoMnSOD mRNA expression was significantly up-regulated in intestine, mantle, gills, digestive gland and haemocytes after Vibrio alginolyticus injection. These results suggested that PoMoSOD was an acute-response protein involved in the innate immune responses of pearl oyster, and provided general information about the mechanisms of innate immune defense against bacterial infection in pearl oyster.
authors.affiliation: Division of Aquaculture and Biotechnology, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Guangzhou 510300, China.
authors.forename: Dianchang
authors.initials: D
authors.lastname: Zhang
authors.forename: Shuge
authors.initials: S
authors.lastname: Cui
authors.forename: Huayang
authors.initials: H
authors.lastname: Guo
authors.forename: Shigui
authors.initials: S
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D049911:Pinctada / Q000201:enzymology / Q000235:genetics* / Q000276:immunology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D017385:Sequence Homology; D013482:Superoxide Dismutase / Q000235:genetics* / Q000276:immunology; D014157:Transcription Factors / Q000276:immunology
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D014157:Transcription Factors; D013482:Superoxide Dismutase
keywords: Expression analysis; Genomic structure; Manganese superoxide dismutase; Pearl oyster