2000 Fiscal Year Final Research Report Summary
Study of gonad-stimulating substance (GSS) and 1-methyladenine which are related to starfish oocyte maturation
| Project/Area Number |
11640672
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物形態・構造
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| Research Institution | Teikyo Junior College |
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Principal Investigator |
MITA Masatoshi Teikyo Junior College, Department of Domestic Science, Lectural, 生活科学科, 講師 (50190674)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Oocyte maturation / Gonad-stimulating substance / Glycoprotein hormone receptor / 1-Methyladenine / Ovarian follicle cells / Starfish |
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| Research Abstract |
1. cDNA cloning of glycoprotein-hormone receptor family
Using degenerate primers derived from consensus sequences of the memmalian glycoprotein hormone (LH, FSH and TSH) receptors, we cloned cDNAs (apGPHR) from ovaries of the starfish Asterina pectinifera. However, a partially purified gonad-stimulating substance (GSS) failed to increase cyclic AMP levels in COS-7 cells expressing apGPHR.This suggests that a new neural petide other than GSS is a ligand for the apGPHR in starfish.
2. 1-Methyladenine biosynthesis and its regulation
Previous in vitro studies have shown that 1-methyladenine (1-MeA) is produced from ATP and S-adenosylmethionine (SAM). In a cell-free system using follicle cells homogenized with a buffer solution, 1-MeA was also produced from ATP and SAM in the presence of cyclic AMP in a concentration dependent manner. It is possible that a unique methyltransferase is activated by cyclic AMP to produce 1-MeA, although it is unclear whether ATP is methylated directly or indirectly by SAM.
3. 1-Methyladenine receptor
Ten N1-substituted adenines as 1-MeA analogues were newly synthesized and used for analysis of the interaction between 1-MeA and its receptors on the surface of oocytes. It was suggested that regional specific structures of the N1-site of adenine are important to interact with 1-MeA receptors. In addition, on the molecular structure a negative charge in N1-site of adenine is required for the binding of the receptors.
Others : A high activity of ecto-ATP diphosphohydrolase (ATPDase) was present on the surface of ovarian follicle cells. It is unlikely that ecto-ATPDase is directly involved in 1-MeA production, but adenosine and AMP produced by ecto-ATPDase is responsible for prevention of precocity before oocyte maturation stage.
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Research Products
(10 results)
