title: Identification and functional characterization of a novel member of low-density lipoprotein receptor-related protein (LRP)-like family in amphioxus.
abstract: Low-density lipoprotein receptor-related protein (LRP) is a group of important endocytic receptors contributing to binding ligands and maintaining internal environment. In this study, we identified a soluble LRP-like molecule in the amphioxus B. japonicum, BjLRP, with an uncharacterized domain structure combination of LY-EGF-CRD-EGF-CRD. It was mainly expressed in the gill, muscle, notochord and testis, and was significantly up-regulated following the challenge with bacteria. Recombinant BjLRP was capable of interacting with both Gram-negative and positive bacteria as well as PAMPs including lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN). Interestingly, recombinant LY peptide was also able to bind to the Gram-negative and positive bacteria as well as the PAMPs LPS, LTA and PGN. By contrast, none of recombinant EGF1, EGF2, CRD1 and CRD2 had affinity to the bacteria and the PAMPs. In addition, BjLRPΔLY had no affinity to the PAMPs, although BjLRPΔLY showed slight affinity to the bacteria. These suggest that the interaction of BjLRP with the bacteria and PAMPs was primarily attributable to the LY domain. It is clear that BjLRP is a novel pattern recognition protein capable of identifying and interacting with invading bacteria in amphioxus.
authors.affiliation: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Baozhen
authors.initials: B
authors.lastname: Qu
authors.affiliation: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Zengyu
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Deyan
authors.initials: D
authors.lastname: Jiao
authors.affiliation: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Department of Marine Biology, Ocean University of China, Qingdao 266003, China. Electronic address: jamesdong@ouc.edu.cn.
authors.forename: Guangdong
authors.initials: G
authors.lastname: Ji
authors.affiliation: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Department of Marine Biology, Ocean University of China, Qingdao 266003, China. Electronic address: sczhang@ouc.edu.cn.
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D026502:LDL-Receptor Related Proteins / Q000235:genetics* / Q000378:metabolism; D064175:Lancelets / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D008070:Lipopolysaccharides / Q000378:metabolism; D011485:Protein Binding
chemical_list: D026502:LDL-Receptor Related Proteins; D008070:Lipopolysaccharides
keywords: Amphioxus; Branchiostoma japonicum; Innate immunity; Low-density lipoprotein receptor-related protein (LRP); Pattern recognition receptor (PRR)