title: Cloning and characterization of two different L-type lectin genes from the Chinese mitten crab Eriocheir sinensis.
abstract: L-type lectins contain a leguminous lectin domain and bind to high-mannose type oligosaccharides. In the secretory pathway, L-type lectins play crucial functions in the trafficking, sorting, and targeting of maturing glycoproteins. This study identified two novel L-type lectins, designated as EsERGIC-53 and EsVIP36, from the Chinese mitten crab Eriocheir sinensis. The complete nucleotide sequence of ERGIC-53 cDNA was 1955 bp, containing a 1506 bp open reading frame (ORF) encoding a putative protein of 501 deduced amino acids. The full-length cDNA of VIP36 was 3474 bp with a 984 bp ORF encoding a 327-amino acid peptide. The deduced ERGIC-53 and VIP36 proteins contained a putative signal peptide and an L-type lectin-like domain. Phylogenetic analysis showed that ERGIC-53 and VIP36 belonged to different clades of L-type lectin family. Reverse transcription PCR showed that ERGIC-53 and VIP36 were expressed in all tested tissues. Quantitative real-time RT-PCR analysis revealed that ERGIC-53 and VIP36 transcripts in hepatopancreas were significantly induced at various time points after infection with lipopolysaccharide (LPS), peptidoglycan (PGN), Staphylococcus aureus, Vibrio parahaemolyticus, and Aeromonas hydrophila. A bacterium-binding experiment showed that both ERGIC-53 and VIP36 could bind to different microbes. Sugar binding assay revealed that these lectins could also bind to the glycoconjugates of bacteria surface, such as LPS, PGN, d-Mannose, and N-Acetyl-d-mannosamine. Moreover, these two L-type lectins agglutinated bacteria in a calcium-dependent manner, and both exerted the ability of facilitating the clearance of injected bacteria V. parahaemolyticus in the crab. Our results suggested that ERGIC-53 and VIP36 functioned as pattern recognition receptors in the immune system of E. sinensis.
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China.
authors.forename: Jing-Min
authors.initials: JM
authors.lastname: Tan
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China.
authors.forename: Shao-Wu
authors.initials: SW
authors.lastname: Yin
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China. Electronic address: njnuwang@263.net.
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China. Electronic address: renqian0402@126.com.
authors.forename: Qian
authors.initials: Q
authors.lastname: Ren
mesh_terms: D000371:Agglutination; D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D060829:Arthropod Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D003001:Cloning, Molecular; D017124:Conserved Sequence; D015870:Gene Expression; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D037102:Lectins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000737:chemistry; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013211:Staphylococcus aureus / Q000187:drug effects / Q000276:immunology; D014736:Vibrio parahaemolyticus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D060829:Arthropod Proteins; D037102:Lectins; D008070:Lipopolysaccharides
keywords: ERGIC-53; Eriocheir sinensis; Innate immunity; Pattern recognition receptor; VIP36