title: Molecular cloning, characterization and expression of a C-type lectin cDNA in Chinese mitten crab, Eriocheir sinensis.
abstract: C-type lectins are pattern-recognition proteins which are functionally important for pathogen recognition and immune regulation in vertebrates and invertebrates. In this study, a lectin cDNA named as Es-Lectin was cloned and characterized from the Chinese mitten crab, Eriocheir sinensis. The full-length sequence of this Es-Lectin cDNA was 651 bp, including an open reading frame of 483 bp encoding 160 amino acids. The predicted molecular weight of the Es-Lectin was 11.8 kDa. A typical signal peptide of 21 amino acids was deduced at the N-terminus of the predicted protein. This Es-Lectin belongs to a C-type lectin and contains six cysteines, a conserved EPN motif (Glu-Pro-Asn) and an imperfect WND (Trp-Asn-Asp) motif (FND, Phe-Asn-Asp). This Es-Lectin had 55% and 32% identity with other two C-type lectins in E. sinensis, and 29-36% homology with decapods. Although the Es-Lectin was also expressed in gill, hepatopancreas, intestine, muscle and stomach, its expression in haemocytes was the greatest. The expression of Es-Lectins in haemocytes increased at 1.5 h after the Aeromonas hydrophila challenge. After a slight decrease, the Es-Lectin expression in haemocytes significantly increased at 48 h post-challenge. The diverse distribution of Es-Lectin and its enhancement by bacterial challenge indicate that C-type lectins are important in the innate immune response to bacterial infection, and can be activated for innate immune response in crab at the initial stage after pathogen infection.
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200062, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Liqiao
authors.initials: L
authors.lastname: Chen
authors.forename: Jianguang
authors.initials: J
authors.lastname: Qin
authors.forename: Daxian
authors.initials: D
authors.lastname: Zhao
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.forename: Chuanjie
authors.initials: C
authors.lastname: Qin
authors.forename: Na
authors.initials: N
authors.lastname: Yu
authors.forename: Erchao
authors.initials: E
authors.lastname: Li
mesh_terms: D016980:Aeromonas hydrophila; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000276:immunology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D037181:Lectins, C-Type / Q000235:genetics* / Q000276:immunology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000276:immunology / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D037181:Lectins, C-Type; D012333:RNA, Messenger