PROGESTERONE RECEPTOR REGULATION

孕酮的作用，一种在控制 女性生殖组织的功能和生长，如乳房 和子宫，似乎是通过与细胞内 孕酮受体（PR）。 虽然我们对这一点了解很多， 这种蛋白质的性质，很少有人知道的合成和降解 PR和调节这些比率的因素。 我们的初步研究 为PR的生物合成、非酶结合前体提供了证据 而当它与公共关系相关联时， 抗白细胞介素RU 486与白细胞介素。 我们的目标是研究荷尔蒙因素 参与PR水平和营业额的调节，以调查 PR的生物合成前体，并检查核PR的性质 配合物 我们将使用密度偏移技术来研究周转率 动力学受配体性质的影响（配体蛋白vs 抗胰蛋白酶素）和受体占有水平。 我们将比较 其中PR处于雌激素控制下的系统（MCF-7人乳腺癌 和大鼠子宫细胞）和不依赖雌激素（T47 D人乳腺癌 癌细胞）。 我们将利用动力学模型，从该PR 前体池大小和生物合成、活化和降解速率 常数可以推导出来，我们将试图表征前体 这些方法也将使我们能够 解决雌二醇是否增加PR水平的重要问题， 受体合成、前体激活或稳定的变化 PR. 由于我们已经发现核PR与抗孕激素复合物 沉积物作为6 S物种的条件下， 是专门的4S，我们将研究影响6S/4S比率的因素， 通过交联测定6S物质的亚基组成， 光亲和标记，并评估6S物质是否代表 “未活化”的非DNA结合形式的PR。这些研究应该提供新的 关于这种重要的生物合成和降解的信息 调节蛋白，并对受体相互作用，可能是基础 β-淀粉样蛋白拮抗剂作用。

The actions of progesterone, a hormone of central importance in controlling the function and growth of female reproductive tissues, such as the breast and uterus, appear to be mediated via interaction with an intracellular protein, the progesterone receptor (PR). Although much is known about the nature of this protein, little is known about the synthesis and degradation of PR and factors that regulate these rates. Our initial studies have provided evidence for a biosynthetic, non hormone-binding precursor of PR and for differences in the form of PR when it is associated with the antiprogestin RU486 vs progestin. Our aims are to study hormonal factors involved in regulation of PR levels and turnover, to investigate biosynthetic precursors of PR, and to examine the nature of nuclear PR complexes. We will use the density shift technique to examine how turnover kinetics are affected by the nature of the ligand (progestin vs antiprogestin) and the level of receptor occupancy. We will compare systems in which PR is under estrogen control (MCF-7 human breast cancer and rat uterine cells) and independent of estrogen (T47D human brease cancer cells). We will utilize a kinetic model, from which the PR precursor pool size and biosynthetic, activation and degradation rate constants can be derived, and we will attempt to characterize the precursor using monoclonal antibodies to PR. These approaches will also enable us to address the important issue of whether estradiol increases PR levels by changes in receptor synthesis, precursor activation, or stabilization of PR. Since we have found that nuclear PR complexes with antiprogestin sediment as 6 S species under conditions where the complexes with progestin are exclusively 4 S, we will examine factors that affect the 6 S/4 S ratio, determine the subunit composition of the 6 S species by crosslinking and photoaffinity labelling, and evaluate whether the 6 S species represents an "unactivated" non-DNA binding form of PR. These studies should provide new information on the biosynthesis and degradation of this important regulatory protein, and on the receptor interactions that may underlie progestin antagonist action.