2004 Fiscal Year Final Research Report Summary
Biodefense function of fish lectin family which bind to pathogenic bacteria and microspodian parasites
| Project/Area Number |
14360118
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fisheries chemistry
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| Research Institution | Tohoku University |
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Principal Investigator |
MURAMOTO Koji Tohoku University, Graduate School of Life Sciences, Professor, 大学院・生命科学研究科, 教授 (90157800)
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| Co-Investigator(Kenkyū-buntansha) |
OGAWA Tomohisa Tohoku University, Graduate School of Life Sciences, Associate Professor, 大学院・生命科学研究科, 助教授 (80240901)
NAGANUMA Takako Tohoku University, Graduate School of Life Sciences, Research Associate, 大学院・生命科学研究科, 助手 (50250733)
SANEYOSHI Mineo Teikyo University of Science and Technology, Faculty of Science and Technology, Professor, 理工学部, 教授 (20002339)
YOKOYAMA Hiroshi The University of Tokyo, Graduate School of Agricultural and Life Sciences, Assistant Professor, 大学院・農学生命科学研究科, 助手 (70261956)
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| Project Period (FY) |
2002 – 2004
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| Keywords | lectin / rhamnose / fish eggs / microsporidium / salmon / ayu / Spanish mackerel / carbohydrate chain |
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| Research Abstract |
L-Rhamnose-binding lectins (RBLs), named CSL1〜3, SML, and SFL, were isolated and characterized from the eggs of chum salmon, Spanish mackerel, and ayu, respectively. They were composed of two or three tandemly repeated domains, which consisted of about 100 amino acid residues with 30〜55% sequence identity. SML was the first RBL, which was a glycoprotein. The structure of the sugar chain and the assignment of 8 disulfide bonds of SML were determined. On the basis of the sequences, the molecular evolution of the carbohydrate recognition domains (CRD) was discussed phylogenetically in term of their structure-function relationship. RBLs agglutinated Gram-negative and Gram positive bacteria by recognizing the structures of lipopolysaccharide and lipoteichoic acid on their surfaces, respectively. RBLs tightly bound to the microspodian, Glugea plecoglossi, via glycoproteins and glycolipids on the surface in a concentration-dependent manner as shown by fluorescence spectrometer and confocal laser scanning microscope. The binding could not be inhibited by L-rhmnose, indicating the presence of a specific binding site besides CRD. The treatment of the spores with SFL could not prevent the transmission to ayu. RBLs also bound to rainbow trout gonal cultured cells, RTG-2, and stimulated the interleukin-8 gene expression, but not IL-1β gene in the cells. The tissue distribution of RBLs demonstrated that the lectins expressed in the liver was transported to the immune system and oocytes via blood stream. These results suggest that RBLs function as non-self recognition molecules in the innate immunity not only in the eggs but also in the adult fishes.
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Research Products
(24 results)
