title: Cloning and characterization of two lipopolysaccharide-binding protein/bactericidal permeability-increasing protein (LBP/BPI) genes from the sea cucumber Apostichopus japonicus with diversified function in modulating ROS production.
abstract: Lipopolysaccharide-binding protein and bactericidal permeability-increasing protein (LBP/BPI) play crucial role in modulating cellular signals in response to Gram-negative bacteria infection. In the present study, two isoforms of LBP/BPI genes (designated as AjLBP/BPI1 and AjLBP/BPI2, respectively) were cloned from the sea cucumber Apostichopus japonicus by RACE approach. The full-length cDNAs of AjLBP/BPI1 and AjLBP/BPI2 were of 1479 and 1455 bp and encoded two secreted proteins of 492 and 484 amino acid residues, respectively. Signal peptide, two BPI/LBP/CETP and one central domain were totally conserved in the deduced amino acid of AjLBP/BPI1 and AjLBP/BPI2. Phylogentic analysis further supported that AjLBP/BPI1 and AjLBP/BPI2 belonged to new members of invertebrates LBP/BPI family. Spatial expression analysis revealed that both AjLBP/BPI1 and AjLBP/BPI2 were ubiquitously expressed in all examined tissues with the larger magnitude in AjLBP/BPI1. The Vibrio splenfidus challenge and LPS stimulation could significantly up-regulate the mRNA expression of both AjLBP/BPI1 and AjLBP/BPI2, with the increase of AjLBP/BPI2 expression occurred earlier than that of AjLBP/BPI1. More importantly, we found that LPS induced ROS production was markedly depressed after AjLBP/BPI1 knock-down, but there was no significant change by AjLBP/BPI2 silencing. Consistently, the expression level of unclassified AjToll, not AjTLR3, was tightly correlated with that of AjLBP/BPI1. Silencing the AjToll also depressed the ROS production in the cultured coelomocytes. All these results indicated that AjLBP/BPI1 and AjLBP/BPI2 probably played distinct roles in bacterial mediating immune response in sea cucumber, and AjLBP/BPI1 depressed coelomocytes ROS production via modulating AjToll cascade.
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Yina
authors.initials: Y
authors.lastname: Shao
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China. Electronic address: lichenghua@nbu.edu.cn.
authors.forename: Chenghua
authors.initials: C
authors.lastname: Li
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Che
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Pengjuan
authors.initials: P
authors.lastname: Zhang
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Duan
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D055785:Gene Knockdown Techniques; D006801:Humans; D007113:Immunity, Innate; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012616:Sea Cucumbers / Q000502:physiology*; D015398:Signal Transduction; D014733:Vibrio / Q000276:immunology*; D014735:Vibrio Infections / Q000276:immunology*; D000099231:Lipopolysaccharide-Binding Protein
chemical_list: D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D020033:Protein Isoforms; D017382:Reactive Oxygen Species; D000099231:Lipopolysaccharide-Binding Protein
keywords: Apostichopus japonicus; Lipopolysaccharide-binding protein/bactericidal permeability–increasing protein; RNA interference; Respiratory burst; Toll like receptor