title: A novel C-type lectin (Cflec-3) from Chlamys farreri with three carbohydrate-recognition domains.
abstract: C-type lectins are a superfamily of carbohydrate-recognition proteins which play crucial roles in the innate immunity. In this study, the gene of a C-type lectin with multiple carbohydrate-recognition domains (CRDs) from scallop Chlamys farreri (designated as Cflec-3) was cloned by rapid amplification of cDNA ends (RACE) approach based on expression sequence tag (EST) analysis. The full-length cDNA of Cflec-3 was of 2256 bp. The open reading frame encoded a polypeptide of 516 amino acids, including a signal sequence and three CRDs. The deduced amino acid sequence of Cflec-3 showed high similarity to members of C-type lectin superfamily. By fluorescent quantitative real-time PCR, the Cflec-3 mRNA was mainly detected in hepatopancreas, adductor, mantle, and marginally in gill, gonad and hemocytes of healthy scallops. After scallops were challenged by Listonella anguillarum, the mRNA level of Cflec-3 in hemocytes was up-regulated and was significantly higher than that of blank at 8 h and 12 h post-challenge. The function of Cflec-3 was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli BL21 (DE3)-pLysS. The recombined Cflec-3 (rCflec-3) agglutinated Gram-negative bacteria Pseudomonas stutzeri. The agglutinating activity was calcium-dependent and could be inhibited by D-mannose. These results collectively suggested that Cflec-3 was involved in the immune response against microbe infection and contributed to nonself-recognition and clearance of bacterial pathogens in scallop.
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Song
authors.forename: Jianmin
authors.initials: J
authors.lastname: Zhao
authors.forename: Limei
authors.initials: L
authors.lastname: Qiu
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Cong
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000371:Agglutination; D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D037181:Lectins, C-Type / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D049897:Pectinidae / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000302:isolation & purification; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013995:Time
chemical_list: D018076:DNA, Complementary; D037181:Lectins, C-Type; D011994:Recombinant Proteins