MOLECULAR CONTROL OF HORMONALLY RESPONSIVE GENES

在时间和空间精确模式中的基因调控是完整的 到正常的发育过程。荷尔蒙，组织特异性和 发育调控可以从分子和遗传两个方面进行分析 小鼠C4/SLP基因家族的研究进展 组织相容性复合体。补语的第四个成分C4是 在体液免疫的效应机制中必不可少。在.期间 在进化过程中，C4基因经历了复制，允许分化 在功能和监管方面。复制品的乘积 SLP(性别限制蛋白)基因在结构上与C4相似，但 不参与补体途径，受雄激素调节。 在DNA水平上的广泛同源性发生在编码区和上游 以及这些邻近基因的下游。监管方面的差异 这两个基因都是在同种小鼠品系中发现的，都是由于等位基因造成的。 变异以及非连锁基因。因此，这是一个模型系统 其中DNA序列的差异与DNA序列的差异 监管；进一步的比较可以确定具体因素 在基因控制方面。 这项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；ii)反式作用 直接或间接与这些序列相互作用的因素；三) 决定发育的顺式和反式元素的相互作用 监管。 顺式作用序列将通过转染克隆的基因和 基因结构。系统性红斑狼疮的激素调节是由于上游的 从前LTR派生的增强器元素；该元素将是 突变以定义内部结构域和精确的序列要求。 反式作用因子将通过它们的序列来识别- 特定的绑定。生化特征将有助于分离出 编码这些蛋白质的基因，其功能和调节可能是 更容易被检查。 发育调节特别容易在 C4/SLP系统由于其遗传学和由于主要部位 表现为肝脏，在之前、期间和期间都有充分分化 在雄激素转录激活SLP之后。照明的照明 SLP和C4调节的分子基础将与一般相关 基因表达、荷尔蒙控制和进化的机制。

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.