MOLECULAR CONTROL OF HORMONALLY RESPONSIVE GENES

基因调控在时间和空间上的精确模式是不可或缺的 正常的发育过程。 激素，组织特异性和 发育调控可以从分子和遗传学角度进行分析 小鼠主要的C4/Slp基因家族的方法 组织相容性复合体 C4是补体的第四种成分， 在体液免疫的效应器机制中必不可少。 期间 在进化过程中，C4基因经历了复制， 在功能和管理方面。 复制品的乘积 基因Slp（性别限制蛋白）在结构上与C4相似，但 不参与补体途径，受雄激素调节。 DNA水平上的广泛同源性发生在编码区和上游 和这些邻近基因的下游。 监管差异 这两种基因都存在于同类小鼠品系中， 变异和非连锁基因。 因此，这是一个模型系统 将DNA序列的差异与 法规;进一步比较可以确定具体因素 基因控制。 该提案的具体目标是在分子水平上界定： I）参与激素调节的顺式作用序列; 与这些序列直接或间接相互作用的因子; III） 顺式和反式元素的相互作用， 调控 顺式作用序列将通过转染克隆的基因来定义， 基因构建体。 Slp的激素调节是由于上游的 增强子元件，其衍生自前病毒LTR;该元件将是 诱变以确定内部结构域和确切的序列要求。 反式作用因子将根据它们的序列来识别- 特异性结合。 生物化学表征将有助于分离 编码这些蛋白质的基因，其功能和调节，然后可能是 更容易检查。 发展调节特别容易在 C4/Slp系统，由于其遗传学和因为主要网站的 表达是肝脏，其在之前、期间和之后完全分化。 在雄激素激活Slp的转录后。 照明 Slp和C4调节的分子基础将与一般的 基因表达、激素控制和进化的机制。

Gene regulation in temporally and spatially precise patterns is integral to normal developmental processes. Hormonal, tissue-specific and developmental regulation can be analyzed by molecular and genetic approaches in the C4/Slp gene family of the mouse major histocompatibility complex. C4, the fourth component of complement, is essential in the effector mechanism of humoral immunity. During evolution, the C4 gene has undergone duplication, allowing divergence with respect to function and regulation. The product of the duplicate gene, Slp (sex-limited protein), is structurally similar to C4, but does not participate in the complement pathway and is regulated by androgen. Extensive homology at the DNA level occurs in coding regions and upstream and downstream of these neighboring genes. Regulatory differences of both genes are found in congenic mouse strains and are due to allelic variation as well as nonlinked genes. Thus this serves as a model system in which to correlate differences in DNA sequence with differences in regulation; further comparison allows identification of specific factors in gene control. The specific aims of this proposal are to define at the molecular level: I) cis-acting sequences involved in hormonal regulation; II) trans-acting factors that interact directly or indirectly with these sequences; III) interactions of cis and trans elements that specify developmental regulation. Cis-acting sequences will be defined by transfection of cloned genes and gene constructs. Hormonal regulation of Slp is due to an upstream enhancer element that derives from a proviral LTR; this element will be mutagenized to define internal domains and exact sequence requirements. Trans-acting factors will be identified by virtue of their sequence- specific binding. Biochemical characterization will aid isolation of genes encoding these proteins, whose function and regulation may then be more readily examined. Developmental regulation is particularly accessible to analysis in the C4/Slp system due to its genetics and because the major site of expression is liver, which is fully differentiated before, during and after transcriptional activation of Slp by androgen. Illumination of the molecular basis of Slp and C4 regulation will be relevant to general mechanisms of gene expression, hormonal control and evolution.