title: Particularity and universality of a putative Gram-negative bacteria-binding protein (GNBP) gene from amphioxus (Branchiostoma belcheri): insights into the function and evolution of GNBP.
abstract: Gram-negative bacteria-binding proteins (GNBPs) are important pattern recognition proteins (PRPs), which can initiate host defense in response to pathogen surface molecules. The roles of GNBP in innate immunity of arthropods and molluscs have recently been reported. However, the GNBP gene has not been characterized in the species of higher evolutionary status yet. In this study, we identified and characterized an amphioxus GNBP gene (designated as AmphiGNBP). First, we identified and cloned the AmphiGNBP and found that the AmphiGNBP encodes a putative protein with 558 amino acids, which contains a conserved β-1, 3-glucan recognizing and binding domain. Second, we found that the AmphiGNBP encodes two extra WSC (cell Wall integrity and Stress response Component) domains, which are unique in AmphiGNBP protein. The two WSC domains of AmphiGNBP protein coupled with the expansion of amphioxus immunity repertoire might undergo intensive domain shuffling during the age of the Cambrian explosion. Finally, we found that the AmphiGNBP was mainly expressed in immune tissues, such as hepatic cecum and intestine, and the expression of AmphiGNBP was affected after LPS stimulation. In conclusion, our findings disclose the particularity and universality of AmphiGNBP and provide profound insights into the function and evolution of GNBP.
authors.affiliation: Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jin
authors.forename: Lu
authors.initials: L
authors.lastname: Zhou
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Song
authors.forename: Jinjun
authors.initials: J
authors.lastname: Qian
authors.forename: Liming
authors.initials: L
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Ma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D043344:Chordata / Q000235:genetics* / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000276:immunology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D008070:Lipopolysaccharides; D012333:RNA, Messenger