REGULATION OF ESTROGEN RESPONSIVE GENES

这项研究的长期目标是了解机制， 类固醇激素通过它来指导基因的转录。 这项建议 旨在研究生物效应的分子基础， 雌激素在鸟类繁殖中的作用 蛋黄蛋白基因都是 对雌激素敏感;然而，诱导的动力学变化。 以下 雌激素、极低密度载脂蛋白II（apo-II） RNA在2-3小时内出现，而在RNA出现之前有大约20小时的滞后。 可以测量卵黄蛋白原I（VTG-I）RNA。 这些的基础 差异完全未知。 所提出的实验设计 为了研究雌激素反应元件的作用， 另外的转录因子，并确定这些转录因子是否 差异反映了雌激素的主要和/或次要作用。 到 为了实现这一目标，有关几个调控区域的信息 基因是必需的。 VTG-II基因的特征在于 调节成分和基因结构。 序列分析及 足迹数据可用于apo-II基因，但功能 分析仍有待完成。 本提案的具体目标 1）鉴定指导转录的apo-II基因座的序列 2）分离和表征基因组， 编码VTG-I基因的克隆，3）鉴定VTG-I基因座的序列 在功能测定中指导基因的转录，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 主要用于通过转染进行DNA序列的功能分析 进入雌激素应答的人肝癌细胞系HepG 2。 一种新型 将使用两种不同的报告基因的方法， 共转染以允许在相同细胞中分析。 类固醇激素在生殖和发育中至关重要， 健康和疾病。 关于类固醇作用机制的基本信息 监管应提供一个基础，以了解增长， 激素依赖性肿瘤，并可能导致改善药物治疗， 雌激素依赖性乳腺肿瘤

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.