title: Molecular diversity of skin mucus lectins in fish.
abstract: Among lectins in the skin mucus of fish, primary structures of four different types of lectin have been determined. Congerin from the conger eel Conger myriaster and AJL-1 from the Japanese eel Anguilla japonica were identified as galectin, characterized by its specific binding to beta-galactoside. Eel has additionally a unique lectin, AJL-2, which has a highly conserved sequence of C-type lectins but displays Ca(2+)-independent activity. This is rational because the lectin exerts its function on the cutaneous surface, which is exposed to a Ca(2+) scarce environment when the eel is in fresh water. The third type lectin is pufflectin, a mannose specific lectin in the skin mucus of pufferfish Takifugu rubripes. This lectin showed no sequence similarity with any known animal lectins but, surprisingly, shares sequence homology with mannose-binding lectins of monocotyledonous plants. The fourth lectin was found in the ponyfish Leiognathus nuchalis and exhibits homology with rhamnose-binding lectins known in eggs of some fish species. These lectins, except ponyfish lectin, showed agglutination of certain bacteria. In addition, pufflectin was found to bind to a parasitic trematode, Heterobothrium okamotoi. Taken together, these results demonstrate that skin mucus lectins in fish have wide molecular diversity.
authors.affiliation: Fisheries Laboratory, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Maisaka, Shizuoka 431-0211, Japan. ayuzuru@mail.ecc.u-tokyo.ac.jp
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tasumi
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tsutsui
authors.forename: Masaki
authors.initials: M
authors.lastname: Okamoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suetake
mesh_terms: D000818:Animals; D004524:Eels; D005399:Fishes / Q000378:metabolism*; D037161:Galectins; D037102:Lectins / Q000737:chemistry*; D009093:Mucus / Q000737:chemistry* / Q000378:metabolism; D012210:Rhamnose; D012867:Skin / Q000737:chemistry* / Q000378:metabolism; D023721:Tetraodontiformes
chemical_list: D037161:Galectins; D037102:Lectins; D012210:Rhamnose