1995 Fiscal Year Final Research Report Summary
Studies on Sugar Recognition by Animal Lectins
| Project/Area Number |
05044164
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KAWASAKI Toshisuke Professor, Pharmaceutical Sciences, Kyoto University, 薬学部, 教授 (50025706)
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| Co-Investigator(Kenkyū-buntansha) |
LEE Reiko takasaki Researcher, Biology Departmen, Johns Hopkins University, 生物学部, 研究員
LEE Yuan chuan Professor, Biology Department, Johns Hopkins University, 生物学部, 教授
KAWASAKI Nobuko Associate Professor, College of Medical Technology, Kyoto University, 医療技術短期大学部, 助教授 (70077676)
YAMASHITA Ikuo Professor, Faculty of Engineering, Kyoto Sangyo University, 工学部, 部長 (70025675)
KOZUTSUMI Yasunori Associate Professor, Pharmaceutical Sciences, Kyoto University, 薬学部, 助教授 (70205425)
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| Project Period (FY) |
1993 – 1995
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| Keywords | animal lectin / mannan-binding protein / transcription / promoter / dexamethasone / DNAsequence / mRNA / cytokine |
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| Research Abstract |
Serum mannan-binding protein (MBP) is a C-type lectin which binds to sugar chains terminated with mannose or N-acetylglucosamine residue. Once MBP binds to ligand sugars on a solid support such as bacterial cells, it activates complement through a new pathway called "lectin pathway". The physiological significance of this lectin was demonstrated clearly by the finding that the patients deficient of the lectin in their serum suffer from serious infectious diseases. In the past one year, we have studied the mechanism of the expression of MBP mRNA by analyzing promoter activity of the 5' upstream region of human MBP gene. 5' upstream region gene fragment -845/+69, which contains several consensus sequences in addition to basic promoter elements CAAT and TATA boxes, was inserted into reporter plasmid containing luciferase gene. The resultant construct was transfected into Hep G2 cells, which was shown to express MBP mRNA.Treatment of the transfected cells with cytokines such as IL6, TNF-a, INF-g and PMA (phorbol 12-myristate 13-acetate) did not show any significant effects on the level of expression of luciferase, while dexamethasone inhibited the expression to one half the control level. Step wise deletions of the MBP gene from 5' upstream region resulted in the up and down regulation of the expression suggesting the presence of multiple negative and positive regulatory elements in this promoter regions.
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