title: Pattern recognition protein binds to lipopolysaccharide and β-1,3-glucan and activates shrimp prophenoloxidase system.
abstract: The prophenoloxidase (proPO) system is activated upon recognition of pathogens by pattern recognition proteins (PRPs), including a lipopolysaccharide- and β-1,3-glucan-binding protein (LGBP). However, shrimp LGBPs that are involved in the proPO system have yet to be clarified. Here, we focus on characterizing the role of a Penaeus monodon LGBP (PmLGBP) in the proPO system. We found that PmLGBP transcripts are expressed primarily in the hemocytes and are increased at 24 h after pathogenic bacterium Vibrio harveyi challenge. The binding studies carried out using ELISA indicated that recombinant (r)PmLGBP binds to β-1,3-glucan and LPS with a dissociation constant of 6.86 × 10(-7) M and 3.55 × 10(-7) M, respectively. Furthermore, we found that rPmLGBP could enhance the phenoloxidase (PO) activity of hemocyte suspensions in the presence of LPS or β-1,3-glucan. Using dsRNA interference-mediated gene silencing assay, we further demonstrated that knockdown of PmLGBP in shrimp in vivo significantly decreased the PmLGBP transcript level but had no effect on the expression of the other immune genes tested, including shrimp antimicrobial peptides (AMPs). However, suppression of proPO expression down-regulated PmLGBP, proPO-activating enzyme (PmPPAE2), and AMPs (penaeidin and crustin). Such PmLGBP down-regulated shrimp showed significantly decreased total PO activity. We conclude that PmLGBP functions as a pattern recognition protein for LPS and β-1,3-glucan in the shrimp proPO activating system.
authors.affiliation: Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand and; National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Road, Klong1, Klong Luang, Pathumthani 12120, Thailand.
authors.forename: Piti
authors.initials: P
authors.lastname: Amparyup
authors.affiliation: Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand and.
authors.forename: Jantiwan
authors.initials: J
authors.lastname: Sutthangkul
authors.affiliation: Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand and.
authors.forename: Walaiporn
authors.initials: W
authors.lastname: Charoensapsri
authors.affiliation: Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand and. Electronic address: anchalee.k@chula.ac.th.
authors.forename: Anchalee
authors.initials: A
authors.lastname: Tassanakajon
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D060829:Arthropod Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004156:Catechol Oxidase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D004792:Enzyme Precursors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005936:Glucans / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D037102:Lectins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D033561:Penaeidae / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D011485:Protein Binding; D014733:Vibrio / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014735:Vibrio Infections / Q000235:genetics / Q000378:metabolism
chemical_list: D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D004792:Enzyme Precursors; D005936:Glucans; D037102:Lectins; D008070:Lipopolysaccharides; C038451:pro-phenoloxidase; D004156:Catechol Oxidase