BIOCHEMICAL ACTION OF STEROID HORMONES IN EUKARYOTES

本研究方案旨在进一步开发出一套独特的模型系统 目的：研究类固醇激素与靶细胞的相互作用。 激素作用的生化机制。心得安是一种类固醇激素 在卵菌Achlya中诱导雄性分化 双性恋。这种水霉是最原始的真核生物 已知有性生殖是由类固醇激素控制的 系统。它为荷尔蒙作用的研究提供了几个优点 由于它的细胞组织和生殖系统相对简单。 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antherdiol受体。少校 Achlya胞浆中受体组分的部分表征和显示 与高等生物体中的类固醇受体非常相似。 我们建议循两个主要调查方向推行这个制度。 有关antherdiol受体的分子特性将在 更多细节。为了实现这一点，高纯度的受体制剂 将获得该受体，并将制备针对该受体的单抗 作为进一步分析的必要工具。要分析的属性包括 分子量、亚基和氨基酸组成及受体 磷酸化。受体与另一个受体的可能联系 细胞蛋白质将被记录下来并进行更详细的描述。 此外，还将启动对类固醇激素Oogoniol的研究， 它指导性形态发生的雌性。合适的放射性物质 将制备用于检测和分析卵黄醇的类固醇 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。将与高等生物体进行比较 这应该揭示出一些最一般和最重要的特征 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.