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Biosynthesis of maturation-inducing hormone (1-methyladenine) by starfish ovarian follicle cells and its relation to cell adhesion factor

海星卵泡细胞成熟诱导激素（1-甲基腺嘌呤）的生物合成及其与细胞粘附因子的关系

基本信息

批准号：
09640797
负责人：
MITA Masatoshi
金额：
$ 1.47万
依托单位：
Teikyo Junior College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

1. Biosynthesis of 1-methyladenineTo determine possible substrates of 1-methyladenine (1-MeA) biosynthesis in starfish ovarian follicle cells, [methyl-^<14>C] methionine, [U-^<14>C] adenine and [U-^<14>C] adenosine were used. A direct methyl donor was found to be S-adenosylmethionine and the adenine molecule of 1-MeA to be drived from ATP.Although 1-MeA was also shown to be synthesized partially from SAM by heat tratment, further studies on the enzyme system related to the methylation in vivo should be provide additional insight into 1-MeA biosynthesis in starfish ovarian follicle cells.2.1-Methyladenine production and cell adhesion factorAs a cell adhesion factor, Mg^<2+>-dependent ecto-ATP diphosphohydrolase (ATPDase) was partially purified from starfish ovarian follicle cells. The ecto-ATPDase was located in cell surface and its molecular weight was about 60,000. It is probable that the ecto-ATPDase is responsible for protection of oocytes from phagocytes and parasites during oogenesis.Others : Ten N^1-substituted adenine derivatives were newly synthesized. It was suggested that regional specific structures of the N^1-site of adenine are related to binding with 1-MeA receptors in oocytes. Comparing with starfish oocyte maturation, several Gialpha subunit proteins were identified in medaka (Oryzias latipes) oocytes. During oocyte maturation, Gialpha proteins decreased and were absent in ovulated eggs.

1. 1-甲基腺嘌呤的生物合成为了确定海星卵泡细胞中1-甲基腺嘌呤（1-MeA）生物合成的可能底物，使用了[甲基-^<14>C]甲硫氨酸、[U-^<14>C]腺嘌呤和[U-^<14>C]腺苷。一个直接的甲基供体是S-腺苷甲硫氨酸，而1-MeA的腺嘌呤分子是由ATP驱动的。对体内甲基化相关酶系统的进一步研究将为海星卵泡细胞中1-MeA的生物合成提供额外的见解。甲基腺嘌呤的产生和细胞粘附因子作为一种细胞粘附因子，Mg^<2+>依赖的胞外ATP二磷酸水解酶（ATPDase）从海星卵泡细胞中部分纯化。该酶定位于细胞表面，分子量约为60，000。在卵母细胞发生过程中，胞外ATP酶可能起保护卵母细胞免受吞噬细胞和寄生虫侵害的作用。结果表明，腺嘌呤的N^1位的区域特异性结构与卵母细胞中1-MeA受体的结合有关。与海星卵母细胞成熟比较，青鳉卵母细胞中鉴定出几种Gia α亚基蛋白。在卵母细胞成熟过程中，Gialpha蛋白减少，并在排卵卵中不存在。