title: A C-type lectin isolated from the skin of Japanese bullhead shark (Heterodontus japonicus) binds a remarkably broad range of sugars and induces blood coagulation.
abstract: The aim of this study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein [designated as H. japonicus C-type-lectin (HjCL)] identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, haemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defence on the skin surface especially when the shark is injured and bleeds.
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan tsutsui@kitasato-u.ac.jp.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tsutsui
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Yuma
authors.initials: Y
authors.lastname: Dotsuta
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Ono
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Masanari
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tateno
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Hirabayashi
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan and Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakamura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001777:Blood Coagulation / Q000187:drug effects*; D050260:Carbohydrate Metabolism; D003001:Cloning, Molecular; D006386:Hemagglutination Tests; D037181:Lectins, C-Type / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011485:Protein Binding; D012754:Sharks; D012867:Skin / Q000378:metabolism*
chemical_list: D037181:Lectins, C-Type
keywords: C-type lectin; blood clotting; self-defence; shark skin; sugar specificity