REGULATION OF PROLACTIN GENE EXPRESSION

总体目标是了解参与的分子事件， 催乳素基因的组织特异性、受调控的表达。 催乳素基因在转录水平上受一个 包括雌二醇，表皮生长因子， 促甲状腺激素释放激素和多巴胺。 建议研究 试图研究允许多激素 催乳素转录的调节。 尤其应注意 将集中在催乳素基因的细胞内调节因子 对催乳素基因重要的DNA序列 转录和DNA结合因子与这些相互作用 序列的 具体的目标是方法包括：1）作用 cAMP依赖性蛋白激酶的催化亚基在 介导cAMP对催乳素基因转录的影响将是 通过使用编码热稳定性的合成基因进行检测， 激酶抑制剂2）雌激素的结构特征 大鼠催乳素基因的反应元件，这是必要的， 结合雌二醇受体并刺激转录 将通过构建合成雌激素 应答元件和应答元件的诱变3） 雌激素受体的DNA结合域的特征， 对催乳素和雌激素反应的相互作用很重要 将通过克隆受体的诱变来探索元件 cDNA。 4)将使用接头扫描诱变来剖析 紧邻5'侧翼区的特异性DNA序列的作用 和催乳素的上游增强子/雌激素反应元件 基因5）与特定催乳素相互作用的DNA结合蛋白 基因序列将通过迁移率变动分析鉴定，纯化 通过亲和层析和cDNA克隆。 这些研究应 提高对所涉一般机制的理解 在基因表达的调节以及特定的 调节这种生理上重要的激素。

The overall goal is to understand the molecular events involved in the tissue-specific, regulated expression of the prolactin gene. The prolactin gene is regulated at the transcriptional level by a number of hormones including estradiol, epidermal growth factor, thyrotropin releasing hormone and dopamine. The proposed studied seek to examine the mechanisms which permit the multihormonal regulation of prolactin transcription. In particular attention will be focused on intracellular regulators of prolactin gene transcription, DNA sequences which are important for prolactin gene transcription and on DNA-binding factors which interact with these sequences. The specific aims are approaches include: 1) The role of the catalytic subunit of the cAMP-dependent protein kinase in mediating cAMP effects on prolactin gene transcription will be examined by using a synthetic gene coding for the heat stable inhibitor of the kinase 2) Structural features of the estrogen response element of the rat prolactin gene which are necessary for binding the estradiol receptor and for stimulation of transcription will be examined through construction of synthetic estrogen response elements and mutagenesis of the response element 3) Features of the DNA binding domain of the estrogen receptor which are important for interaction with the prolactin estrogen response element will be explored through mutagenesis of the cloned receptor cDNA. 4) Linker scanning mutagenesis will be used to dissect the role of specific DNA sequences in the immediate 5' flanking region and an upstream enhancer/estrogen response element of the prolactin gene 5) DNA binding proteins which interact with specific prolactin gene sequences will be identified by mobility shift assay, purified by affinity chromatography and cDNAs cloned. These studies should provide increased understanding of the general mechanisms involved in the regulation of gene expression as well as the specific regulation of this physiologically important hormone.