title: Characterization and  bacterial-binding activity of a novel C-type lectin from the red-spotted  grouper, Epinephelus akaara.
abstract: Because of their specific binding to carbohydrates, lectins play a crucial role in pathogen recognition and clearance in vertebrate animals. Previously, only two types of collectins had been isolated from bony fish: mannan-binding lectin (MBL) and galactose-binding lectin (GalBL). We sequenced a novel collectin (designated EALec1) from the red-spotted grouper, Epinephelus akaara. The gene structure of EALec1 and the alignment of the carbohydrate recognition domain of the three collectins demonstrated that EALec1 is a new type of collectin derived from MBL. We examined the expression pattern of the EALec1 transcripts in 12 tissues of the red-spotted grouper. The EALec1 gene was found to have multiple copies; their transcripts were detected in all 12 tissues. EALec1 was also recombined and expressed in Escherichia coli to investigate its immune functions and carbohydrate-binding characterization. We concluded that EALec1 belongs to the mannan-binding lectin group, despite its different Ca²⁺-dependent sites in the carbohydrate recognition domain, and that it is involved in the recognition and clearance of invaders in the red-spotted grouper.
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China.
authors.forename: Z W
authors.initials: ZW
authors.lastname: Zhang
authors.forename: X F
authors.initials: XF
authors.lastname: Shi
authors.forename: M
authors.initials: M
authors.lastname: Qu
authors.forename: S X
authors.initials: SX
authors.lastname: Ding
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001422:Bacterial Adhesion; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D005091:Exons / Q000235:genetics; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D016678:Genome / Q000235:genetics; D007438:Introns / Q000235:genetics; D037181:Lectins, C-Type / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics / Q000378:metabolism*; D018807:Polymorphism, Single-Stranded Conformational; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D037181:Lectins, C-Type; D012333:RNA, Messenger; D011994:Recombinant Proteins