BIOCHEMICAL ACTION OF STEROID HORMONES IN EUKARYOTES

本研究提案旨在进一步开发一个独特的模型系统 研究类固醇激素在靶细胞中的相互作用， 激素作用的生化机制。 雄激素是一种类固醇激素 在卵菌真菌Achlya中诱导雄性性别分化 两性人 这种水霉菌是最原始的真核生物 已知有性生殖由类固醇激素控制 系统 它为激素作用的研究提供了几个优势 由于其相对简单的细胞组织和生殖系统。 在过去的五年里，我们合成了一种放射性类固醇， 已被用于鉴定Achlya中的花药素受体。 主要 Achlya胞质溶胶中的受体组分部分表征并显示 与高等生物的类固醇受体非常相似。 我们建议沿着两条主要的调查路线推行这个制度。 雄二醇受体的分子特性将在 更多细节 为了实现这一点，高度纯化的受体制剂 并制备受体的单克隆抗体 作为进一步分析的必要工具。 要分析的属性包括 分子量、亚基和氨基酸组成以及受体 磷酸化 受体与另一个受体的可能联系 将更详细地记录和描述细胞蛋白。 此外，还将开始对类固醇激素卵果醇进行研究， 指导雌性的性形态发生。 合适的放射性 将制备甾体用于卵母细胞醇的检测和分析 Achlya中的受体。 这些研究应该为发展提供一些非常重要的工具 这个实验模型。 将与高等生物进行比较 这应该揭示了一些最普遍和最重要的特征， 真核生物中的类固醇调节。

This research proposal is designed to further develop a unique model system to study the interactions of steroid hormones in target cells and the biochemical mechanism of hormone action. Antheridiol is a steroid hormone which induces male sexual differentiation in the oomycete fungus, Achlya ambisexualis. This water mold is the most primitive eukaryotic organism known in which sexual reproduction is controlled by a steroid hormone system. It offers several advantages for investigations on hormone action due to its relatively simple cellular organization and reproductive system. Over the past five years, we have synthesized a radioactive steroid that has been used to identify antheridiol receptors in Achlya. The major receptor component in Achlya cytosol was partially characterized and shown to be remarkably similar to steroid receptors in higher organisms. We propose to pursue this system along two major lines of investigation. The molecular properties of the antheridiol receptor will be described in greater detail. To achieve this, highly purified receptor preparations will be obtained and monoclonal antibodies to the receptor will be prepared as necessary tools for further analysis. Properties to be analyzed include molecular weight, subunit and amino acid composition, and receptor phosphorylation. The probable association of the receptor with another cellular protein will be documented and described in more detail. In addition, studies will be initiated on the steroid hormone oogoniol, which directs sexual morphogenesis of the female. A suitable radioactive steroid will be prepared for the detection and analysis of oogoniol receptors in Achlya. These studies should provide some very important tools for the development of this experimental model. Comparisons will be made with higher organisms which should reveal some of the most general and important features of steroid regulation in eukaryotes.