1-Methyladenine production from ATP by starfish ovarian follicle cells.
1-Methyladenine production from ATP by starfish ovarian follicle cells.
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海星卵巢卵泡细胞从 ATP 产生 1-甲基腺嘌呤。
DOI：
10.1016/s0304-4165(99)00041-0
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Y. Nagahama
中科院分区：
文献类型：
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作者：
M. Mita;M. Yoshikuni;Y. Nagahama
1-甲基腺嘌呤（1-MeAde）是海星卵泡细胞受桡神经释放的性腺刺激物质（GSS）刺激而产生的卵母细胞成熟诱导物质。我们之前已经表明，GSS导致细胞内ATP水平的降低与1-MeAde的产生一致。本研究考察了1-MeAde的腺嘌呤分子是否直接来源于ATP。当从海星Asterina pectinifera分离的卵泡细胞中预先加载[U-14C]腺嘌呤或[U-14C]腺苷时，细胞内放射性标记的腺嘌呤核苷酸水平增加，特别是ATP。与GSS进一步孵育后，细胞内放射性标记ATP水平下降，同时培养基中[14C]1-MeAde水平显著升高。GSS作用下消耗的ATP量与1-MeAde产生的ATP量相似。然而，无论GSS是否存在，ADP和AMP的水平都没有变化。这些发现有力地表明，在GSS的影响下，1-MeAde是由ATP作为底物在卵泡细胞中合成的。此外，使用[甲基- 3h]蛋氨酸，发现1-MeAde的甲基来自蛋氨酸。因此，GSS似乎通过海星卵巢卵泡细胞的甲基化过程刺激ATP合成1-MeAde。
1-Methyladenine (1-MeAde), the oocyte maturation-inducing substance in starfish, is produced by ovarian follicle cells upon stimulation with a gonad-stimulating substance (GSS) released from the radial nerves. We have shown previously that GSS causes a reduction in the intracellular levels of ATP coincident with 1-MeAde production. The present study examined whether the adenine molecule of 1-MeAde is directly derived from ATP. When isolated follicle cells from the starfish Asterina pectinifera were preloaded with [U-14C]adenine or [U-14C]adenosine, there was an increase in the intracellular levels of radiolabeled adenine nucleotides, particularly ATP. Following further incubation with GSS, the intracellular levels of radiolabeled ATP decreased, concomitant with a marked increase in the levels of [14C]1-MeAde in the medium. The amount of ATP consumed under the influence of GSS was similar to the amount of 1-MeAde produced. However, there was no change in the levels of ADP and AMP regardless of the presence or absence of GSS. These findings strongly suggest that 1-MeAde is synthesized from ATP as a substrate in follicle cells under the influence of GSS. Furthermore, using [methyl-3H]methionine, the methyl group of 1-MeAde was found to be derived from methionine. Thus GSS appears to stimulate the synthesis of 1-MeAde from ATP via the methylation process in starfish ovarian follicle cells.