REGULATION OF ESTROGEN RESPONSIVE GENES

这项研究的长期目标是了解其作用机制。 类固醇激素通过它来指导基因的转录。这项建议 旨在研究人血清白蛋白生物学效应的分子基础 鸟类繁殖过程中的雌激素。卵黄蛋白基因都是 对雌激素有反应；然而，诱导的动力学有所不同。跟随 雌激素、极低密度载脂蛋白II(apo-II)的应用 RNA在2-3小时内出现，而在此之前有大约20小时的延迟 可以测量卵黄蛋白原I(VTG-I)RNA。这些的基础是 分歧是完全未知的。建议的实验是设计的 为了研究雌激素反应元件的作用，要求 额外的转录因子，并确定这样的 差异反映了雌激素的主要和/或次要影响。至 要实现这一目标，关于几个监管区域的信息 基因是必需的。VTG-II基因的特征是 调节成分和基因结构。序列分析和 Apo-II基因的足迹数据是可用的，但具有功能 分析还有待完成。这项建议的具体目的 是为了1)识别指导转录的apo-II基因座序列 2)基因组的分离和鉴定 编码VTG-I基因的克隆，3)VTG-I基因座序列的鉴定 在功能分析中直接转录基因，以及4) 确定VTG-I基因对雌激素反应缓慢的基础 与apo-II基因的快速反应相比。这些研究将依赖于 主要是通过转染法对DNA序列进行功能分析 将其导入雌激素敏感的人肝癌细胞系HepG2。一本小说 将使用两种不同的报告基因的方法 共转染，以便在相同的细胞中进行分析。 类固醇激素在生殖和发育过程中至关重要，在 健康和疾病。关于类固醇作用机制的基本信息 监管应为理解的增长提供基础 激素依赖性肿瘤，并可能导致改进的药物治疗 雌激素依赖型乳腺肿瘤。

The long range objective of this research is to understand the mechanisms by which steroid hormones direct the transcription of genes. This proposal is designed to examine the molecular basis for the biological effects of estrogen during avian reproduction. The yolk protein genes are all responsive to estrogen; however, the kinetics of induction vary. Following the administration of estrogen, very low density apolipoprotein II (apo-II) RNA appears within 2-3 hours while there is a lag of about 20 hours before vitellogenin I (VTG-I) RNA can be measured. The basis for these differences is completely unknown. The proposed experiments are designed to examine the role of estrogen response elements, the requirement for additional transcriptional factors, and to determine whether such differences reflect primary and/or secondary effects of estrogen. To accomplish this goal, information about the regulatory regions of several genes is required. The VTG-II gene has been characterized in terms of regulatory components and gene structure. Sequence analysis and footprinting data are available for the apo-II gene, but functional analysis remains to be accomplished. The specific aims of this proposal are to 1) Identify sequences of the apo-II locus that direct transcription of the gene in functional assays, 2) Isolate and characterize genomic clones coding for the VTG-I gene, 3) Identify sequences of the VTG-I locus that direct transcription of the gene in functional assays, and 4) Determine the basis for the slow response to estrogen of the VTG-I gene compared to the rapid response of the apo-II gene. These studies will rely predominately on functional analysis of the DNA sequences by transfection into the estrogen responsive human hepatoma cell line, HepG2. A novel approach will be used in which two different reporter genes will be cotransfected to allow analysis in the same cells. Steroid hormones are crucial in reproduction and development, as well as in health and disease. Basic information concerning the mechanisms of steroid regulation should provide a foundation for understanding the growth of hormone dependent tumors, and may lead to improved drug therapy for estrogen dependent breast tumors.