title: A prophenoloxidase from Artemia sinica: cDNA cloning, expression and activity analysis during early development.
abstract: To understand the defense mechanisms of Crustacean animals, brine shrimp Artemia sinica prophenoloxidase (AsproPO) cDNA was cloned and its expression at early developmental stages was examined by reverse-transcription PCR (RT-PCR) and semi-quantitative RT-PCR, and activity of phenoloxidase (PO) at different developmental stages was further detected by using l-3,4-dihydroxyphenylalanine (l-DOPA) as a specific substrate in this study. It was found that the full-length of AsproPO cDNA is 2125 bp and it contains an open reading frame of 2100 bp encoding a protein of 699 amino acids. The deduced amino acid sequence of AsproPO has two putative copper binding sites highly conserved in Arthropods. Semi-quantitative RT-PCR analyses showed that the gene of AsproPO expressed at Emergence, Instar I and Instar II stages but did not at 0 h and 6 h stages. Activity measurement showed that PO activity could only be detected at Instar II stage but the other measured stages. All these implied that Artemia proPO immune system was complexly modulated during early development.
authors.affiliation: Department of Marine Biology, College of Marine Life Sciences, Ocean University of China, Yushan Road 5, Qingdao 266003, People's Republic of China. tjfan@ouc.edu.cn
authors.forename: Tingjun
authors.initials: T
authors.lastname: Fan
authors.forename: Liyan
authors.initials: L
authors.lastname: Wang
authors.forename: Xianyuan
authors.initials: X
authors.lastname: Fan
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Yu
authors.forename: Guojian
authors.initials: G
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001156:Artemia / Q000201:enzymology* / Q000276:immunology*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004156:Catechol Oxidase / Q000235:genetics* / Q000378:metabolism*; D003300:Copper / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004792:Enzyme Precursors / Q000235:genetics* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000276:immunology*; D007980:Levodopa / Q000378:metabolism; D008018:Life Cycle Stages / Q000276:immunology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; D004792:Enzyme Precursors; D007980:Levodopa; D003300:Copper; C038451:pro-phenoloxidase; D004156:Catechol Oxidase