title: Identification and expression analysis on bactericidal permeability-increasing protein (BPI)/lipopolysaccharide-binding protein (LBP) of ark shell, Scapharca broughtonii.
abstract: Bactericidal permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP) are the numbers of the lipid transfer protein/lipopolysaccharide-binding protein family and play crucial roles in the innate immune response to Gram-negative bacteria. A novel Sb-BPI/LBP1 from ark shell Scapharca broughtonii was isolated by expressed sequence tag (EST) and RACE techniques. The Sb-BPI/LBP1 cDNA encoded a polypeptide of 484 amino acids with a putative signal peptide of 21 amino acid residues and a mature protein of 463 amino acids. The deduced amino acid sequence of Sb-BPI/LBP1 contained an N-terminal BPI/LBP/CETP domain BPI1 with three functional regions that display LPS-binding activity, and a C-terminal BPI/LBP/CETP domain BPI2. In structure and sequence, Sb-BPI/LBP1 showed highly similar to those of the BPI/LBPs from invertebrate and non-mammalian vertebrate, the LBPs and BPIs from mammal. By quantitative real-time RT-PCR, Sb-BPI/LBP1 transcripts could be detected in all normal tested tissues, including hepatopancreas, adductor muscle, mantle margin, heart, gonad, gill and hemocytes, and was universally up-regulatable at 24 h post LPS challenge. The mRNA expression of Sb-BPI/LBP1 in hemocytes was the most sensitive to LPS challenge, significantly up-regulated at 12 h post LPS challenge and peaked at 24 h (16.76-fold, P < 0.05). These results suggested that Sb-BPI/LBP1 was a constitutive and inducible acute-phase protein contributing to the host immune defense against Gram-negative bacterial infection in ark shell S. broughtonii.
authors.affiliation: Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Shandong Provincial Key Laboratory of Fishery Resources and Eco-environment, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, PR China. maoyz@ysfri.ac.cn
authors.forename: Yuze
authors.initials: Y
authors.lastname: Mao
authors.forename: Chunya
authors.initials: C
authors.lastname: Zhou
authors.forename: Ling
authors.initials: L
authors.lastname: Zhu
authors.forename: Yao
authors.initials: Y
authors.lastname: Huang
authors.forename: Tingru
authors.initials: T
authors.lastname: Yan
authors.forename: Jianguang
authors.initials: J
authors.lastname: Fang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D006090:Gram-Negative Bacteria; D054884:Host-Pathogen Interactions; D008070:Lipopolysaccharides / Q000633:toxicity; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D049894:Scapharca / Q000378:metabolism*; D000099231:Lipopolysaccharide-Binding Protein
chemical_list: D000209:Acute-Phase Proteins; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D002352:Carrier Proteins; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein; C021623:bactericidal permeability increasing protein
keywords: Bactericidal permeability-increasing protein (BPI)/lipopolysaccharide-binding protein (LBP); Immune response; LPS challenge; Scapharca broughtonii; mRNA expression