Yeast-binding C-type lectin with opsonic activity from conger eel (Conger myriaster) skin mucus.
A mannose-specific lectin with agglutination activity against a yeast, Saccharomyces serevisiae, was purified from conger eel (Conger myriaster) skin mucus. The lectin, named conCL-s, has a tetrameric structure consisting of two non-covalently associated dimers whose constituent monomers with a molecular mass of about 16,000 Da are linked by a disulphide bond. conCL-s is composed of 173 amino acid residues including a 24-residue signal peptide, and belongs to the C-type lectin family, which is typically characterized by binding to sugar in a Ca2+-dependent manner. Nevertheless, conCL-s showed Ca2+-independent activity in its yeast-binding. The gene expression of the lectin was widely detected in external and internal mucosal tissues, i.e., skin, gills, tongue, buccal cavity wall and esophagus. In these tissues, mRNA of conCL-s was exclusively distributed in club cells, which are one of the major components of the epidermis and mucosal epithelium in Anguilliforme species. conCL-s showed agglutination activity to a bacterium, Escherichia coli. Furthermore, attachment of the lectin to microspheres significantly enhanced their phagocytosis in conger eel macrophages. These findings suggest that conCL-s acts as an opsonin and plays an important role in the innate immunity on the body surface in conger eels.
Tsutsui
Shigeyuki
S
School of Fisheries Science, Kitasato University, Sanriku, Ofunato, Iwate 022-0101, Japan. tsutsui@kitasato-u.ac.jp
Iwamoto
Kyousuke
K
Nakamura
Osamu
O
Watanabe
Tasuku
T
D000371:Agglutination; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000235:genetics; D004524:Eels / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000276:immunology; D019143:Evolution, Molecular; D041981:Gastrointestinal Tract / Q000378:metabolism; D005880:Gills / Q000378:metabolism; D037181:Lectins, C-Type / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology; D008969:Molecular Sequence Data; D009093:Mucus / Q000737:chemistry; D009895:Opsonin Proteins / Q000276:immunology*; D010587:Phagocytosis; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D012867:Skin / Q000378:metabolism
D018076:DNA, Complementary; D037181:Lectins, C-Type; D009895:Opsonin Proteins