title: Molecular characterization and mRNA expression of catalase from pearl oyster Pinctada fucata.
abstract: Catalase (EC 1.11.1.6) is an important antioxidant enzyme that protects aerobic organisms against oxidative damage by degrading hydrogen peroxide to water and oxygen. In the present study, a catalase cDNA of peal oyster Pincatada fucata (designated as PoCAT) is cloned and characterized by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) methods. PoCAT is 2428 bp long and consists of a 5'-UTR of 140 bp, an unusually long 3'-UTR of 749 bp, and an open reading frame (ORF) of 1539 bp. The ORF of PoCAT encodes a polypeptide of 512 amino acids with molecular weight of 58.1 kDa and the theoretical isoelectric point of 8.4. PoCAT shares 62.3-82.2% identity and 73.0-92.0% similarity to other catalase amino acid sequences. Sequence alignment indicates that PoCAT contains the proximal heme-ligand signature sequence (R³⁵¹LFSYSDT³⁵⁸), the proximal active site signature (F⁶¹NRERIPERVVHAKGGGA⁷⁸), and the three catalytic amino acid residues (His⁷², Asn¹⁴⁵, and Tyr³⁵⁵). PoCAT has two potential glycosylation sites (N⁴³⁶YS⁴³⁸ and N⁴⁷⁸FS⁴⁸⁰) and a peroxisome targeting signal (ASL). PoCAT mRNA was ubiquitously expressed in all detected tissues, and the expression level of PoCAT mRNA was higher in intestine and mantle. The expression profile analysis showed that the expression level of PoCAT mRNA in intestine was significantly up-regulated at 2, 4 and 12 h after Vibrio alginolyticus stimulation. These results demonstrated that PoCAT is a typical member of catalase family and might be involved in innate immune responses of pearl oyster.
authors: Division of Aquaculture and Biotechnology, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
authors: Huayang
authors: H
authors: Guo
authors: Dianchang
authors: D
authors: Zhang
authors: Shuge
authors: S
authors: Cui
authors: Mingqiang
authors: M
authors: Chen
authors: Kaichang
authors: K
authors: Wu
authors: Youning
authors: Y
authors: Li
authors: Tianfeng
authors: T
authors: Su
authors: Shigui
authors: S
authors: Jiang
mesh_terms: D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D007113:Immunity, Innate / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D049911:Pinctada / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D002374:Catalase