ESTROGEN REGULATION OF RAT UTERINE CREATINE KINASE B

大鼠子宫的成熟是性类固醇的一个戏剧性的例子 行动上 青春期前的雌激素激增，或外源性雌激素， 会导致未成熟器官的深度重塑 之一 这一过程中最早的生化事件是一个快速的， 肌酸激酶B（CK B）合成的短暂增加， 子宫内膜和子宫肌层。 人们对这些过程知之甚少 在这种细胞内酶的雌激素调节中起作用， 雌激素调节的模型主要来自研究 卵生脊椎动物的分泌蛋白。 诱导这些 产品对雌激素的反应要慢得多， 通常是特化细胞类型的主要产物。 肌酸激酶B调节的变异特征表明， 替代性监管策略可能会积极参与其监管 通过雌激素;提供了一种新的模型， 目的，了解雌激素作用的分子基础， 追究 本提案将涉及两个方面： 1. 子宫CKB mRNA水平如何改变？ CKB mRNA水平 雌激素给药后数分钟内增加，3小时达到峰值 并在6小时内降至基础水平。 抑制物数据 表明最初的增加是由于增强 转录，但随后的减少发生在一段时间内， 一般蛋白质合成迅速增加。 我们提议， 并将测试雌激素刺激合成的假设 导致CKB mRNA选择性降解的RN'酶。 2. 雌激素刺激CKB的机制是什么 表情？ 雌激素反应元件被发现在几个 雌激素调节基因，但没有这些基序的完美副本。 在CKB基因中发现。 这些数据表明， 序列，或共有基序的多个不完整拷贝， 介导CKB转录的受体激活。 替代品 将通过在雌激素敏感细胞中的转染研究来测试 线 将评价来自CKB基因的片段， 赋予氯霉素雌激素反应性的能力 乙酰转移酶报告序列。 积极的进一步分析 序列将包括受体结合的体外研究。

Maturation of the rat uterus is a dramatic example of sex steroid action. The prepubertal estrogen surge, or exogenous estrogen, causes profound remodeling of the immature organ. One of the earliest biochemical events in this process is a rapid but transient increase in creatine kinase B (CKB) synthesis in both the endometrium and myometrium. Little is known of the processes active in the estrogen regulation of this intracellular enzyme as models for estrogen regulation are primarily derived from studies on secretory proteins in oviparous vertebrates. Induction of these products show a much slower response to estrogen, and they are typically the principal products of specialized cell types. The variant features of creatine kinase B modulation suggest that alternative regulatory strategies may be active in its regulation by estrogen; providing a novel model in which our long term objective, understanding the molecular bases estrogen action can be investigated. Two aspects will be addressed in this proposal: 1. How are levels of uterine CKB mRNA altered? Levels of CKB mRNA increase within minutes of estrogen administration, peak at 3 hours and decline towards basal levels within 6 hours. Inhibitor data indicate that the initial increase is due to enhanced transcription, yet the subsequent decrease occurs during a period when general protein synthesis is increasing rapidly. We propose, and will test, the hypothesis that estrogen stimulates synthesis of an RN'ase leading to the selective degradation of CKB mRNA. 2. What is the mechanism by which estrogen stimulates CKB expression? Estrogen response elements are found in several estrogen regulated genes, but no perfect copies of these motifs are found in the CKB gene. These data suggest that different sequences, or multiple imperfect copies of the consensus motif, mediate receptor activation of CKB transcription. The alternatives will be tested by transfection studies in estrogen sensitive cell lines. Segments from the CKB gene will be evaluated for the ability to confer estrogen responsiveness on a chloramphenicol acetyl transferase reporter sequence. Further analysis of positive sequences will include in-vitro studies of receptor binding.