title: Molecular characterization and functional analysis of a novel C-type lectin receptor-like gene from a teleost fish, Plecoglossus altivelis.
abstract: C-type lectin-like receptors (CLRs) are important pathogen pattern recognition molecules that recognize carbohydrate structures. However, the functions of these receptors in fish keep less known. In this study, we characterized a novel CLR from a teleost fish, Plecoglossus altivelis (ayu), tentatively named PaCD209L. The cDNA of PaCD209L is 1464 nucleotides (nts) in length, encoding a polypeptide of 281 amino acid residues with a calculated molecular weight of 31.5 kDa. Multiple alignment of the deduced amino acid sequences of PaCD209L and other related fish CLRs revealed that the PaCD209L sequence had typical characteristics of fish CLRs, but without Ca(2+)-binding sites. Sequence comparison and phylogenetic tree analysis showed that PaCD209L shared the highest amino acid identity (44%) with rainbow trout (Oncorhynchus mykiss) CD209 aE PaCD209L transcripts were detected in all of the tissues examined, mainly expressed in the brain and heart. Upon Vibrio anguillarum infection, PaCD209L transcripts were upregulated in all tested tissues and in monocytes/macrophages (MO/MΦ). We prepared recombinant PaCD209L (rPaCD209L) by prokaryotic expression and raised antiserum against PaCD209L. Western blot analysis revealed that native PaCD209L was glycosylated, and its protein expression significantly increased in ayu MO/MΦ upon V. anguillarum infection. In addition, rPaCD209L was able to bind Gram-positive and Gram-negative bacteria in the absence of Ca(2+). After PaCD209L was blocked by anti-PaCD209L IgG, the phagocytosis and bacterial killing activity of MO/MΦ significantly decreased. These results suggest that PaCD209L plays an important role in the regulation of MO/MΦ functions in ayu.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Guan-Jun
authors.initials: GJ
authors.lastname: Yang
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Xin-Jiang
authors.initials: XJ
authors.lastname: Lu
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China; The Donghai Sea Collaborative Innovation Center for Industrial Upgrading Mariculture, Ningbo University, Ningbo 315211, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China; The Donghai Sea Collaborative Innovation Center for Industrial Upgrading Mariculture, Ningbo University, Ningbo 315211, China. Electronic address: jchen1975@163.com.
authors.forename: Jiong
authors.initials: J
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000276:immunology; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005434:Flow Cytometry; D037181:Lectins, C-Type / Q000235:genetics* / Q000276:immunology; D008957:Models, Genetic; D008969:Molecular Sequence Data; D036441:Osmeriformes / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D010587:Phagocytosis / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013045:Species Specificity; D014733:Vibrio / Q000276:immunology*
chemical_list: D015815:Cell Adhesion Molecules; D017931:DNA Primers; D018076:DNA, Complementary; D037181:Lectins, C-Type
keywords: Bacterial infection; C-type lectin receptor; Gene expression; Monocyte/macrophage functions; Sequence analysis