title: A single CRD C-type lectin from Eriocheir sinensis (EsLecB) with microbial-binding, antibacterial prophenoloxidase activation and hem-encapsulation activities.
abstract: C-type lectins (CTLs) exist widely in crustaceans. To date, thirteen CTLs have been reported in crustaceans, and play significant roles in pathogen recognition, encapsulation of hemocytes and antimicrobial activity in the innate immune response. Based on the initial expressed sequence tags (EST) of a hepatopancreatic cDNA library, a novel CTL, designated as EsLecB, with a 470 bp open reading frame encodes a polypeptide of 156 amino acids, including a signal peptide of 19 amino acid residues and one carbohydrate-recognition domain of 131 aa residues, was cloned from the crustacean Eriocheir sinensis. By qRT-PCR analysis, EsLecB was detected in all tested tissues, and showed highest expression in hemocytes, hepatopancreas and heart. The expression of EsLecB was up-regulated following injections of PAMPs or bacteria. The recombinant protein (rEsLecB) expressed in Escherichia coli had a calcium-independent but carbohydrate-dependent microbial-binding and microbial-agglutinating, microorganism growth inhibitory and hem-encapsulation activities. Moreover, the rEsLecB could stimulate the activation of prophenoloxidase in vitro. These results indicated that EsLecB, as an antibacterial pattern recognition receptor is involved in innate immunity, and may act as an upstream detector of the prophenoloxidase activating system, which can detect pathogen invasion in E. sinensis.
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Zi-Yan
authors.initials: ZY
authors.lastname: Fang
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Xue-Jie
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: You-Ting
authors.initials: YT
authors.lastname: Zhu
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China. Electronic address: wwli@bio.ecnu.edu.cn.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Li
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China. Electronic address: qwang@bio.ecnu.edu.cn.
authors.forename: Qun
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001419:Bacteria / Q000737:chemistry; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D004156:Catechol Oxidase / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004792:Enzyme Precursors / Q000378:metabolism; D015870:Gene Expression; D007113:Immunity, Innate; D037181:Lectins, C-Type / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D000069452:Pathogen-Associated Molecular Pattern Molecules / Q000494:pharmacology; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D000900:Anti-Bacterial Agents; D060829:Arthropod Proteins; D018076:DNA, Complementary; D004792:Enzyme Precursors; D037181:Lectins, C-Type; D000069452:Pathogen-Associated Molecular Pattern Molecules; D012333:RNA, Messenger; D011994:Recombinant Proteins; C038451:pro-phenoloxidase; D004156:Catechol Oxidase
keywords: Antibacterial activity; C-type lectin; Eriocheir sinensis; Pattern recognition receptor