title: Gene structure of an antimicrobial peptide from mandarin fish, Siniperca chuatsi (Basilewsky), suggests that moronecidins and pleurocidins belong in one family: the piscidins.
abstract: The gene of piscidin, an antimicrobial peptide, has been cloned from the mandarin fish, Siniperca chuatsi. From the first transcription initiation site, the mandarin fish piscidin gene extends 1693 nucleotides to the end of the 3' untranslated region and contains four exons and three introns. A predicted 79-residue prepropeptide consists of three domains: a signal peptide (22 aa), a mature peptide (22 aa) and a C-terminal prodomain (35 aa). The shortage of XQQ motif in the prodomain of mandarin fish piscidin and the similar gene structure between moronecidins (piscidins) and pleurocidins may indicate that they are derived from the same ancestor gene. We thus suggest that piscidin should be used as a terminology for these antimicrobial peptides in the future. The mandarin fish piscidin mRNA was abundant in intestine, spleen, pronephros and kidney analysed by real-time polymerase chain reaction. After stimulation with lipopoly saccharides (LPS), a marked increase in transcripts was observed in most tissues, indicating that piscidin is not only a constitutively expressed molecule, but also has an increased response to bacterial infection. The synthetic, amidated mandarin fish piscidin exhibited different antimicrobial activity against different fish bacterial pathogens, especially against species of Aeromonas, which may to certain extent reflect the pathogenicity of these bacteria.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, and Laboratory of Fish Diseases, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China.
authors.forename: B J
authors.initials: BJ
authors.lastname: Sun
authors.forename: H X
authors.initials: HX
authors.lastname: Xie
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.forename: P
authors.initials: P
authors.lastname: Nie
mesh_terms: D000199:Actins / Q000032:analysis; D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000737:chemistry; D029941:Fish Proteins / Q000032:analysis / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics* / Q000502:physiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012333:RNA, Messenger / Q000737:chemistry; D016415:Sequence Alignment / Q000662:veterinary
chemical_list: D000199:Actins; D023181:Antimicrobial Cationic Peptides; D017931:DNA Primers; D018076:DNA, Complementary; D029941:Fish Proteins; D012333:RNA, Messenger; C449802:moronecidin protein, Morone saxatilis; C105851:pleurocidin