STRUCTURE AND REGULATION OF LIVER ACUTE PHASE GENES

急性期蛋白是由肝细胞产生的，是很重要的 在防御组织损伤和感染方面。字母2- 巨球蛋白(Alpha2M)是一种广泛的蛋白酶抑制剂，它是 在急性和慢性炎症中增加了几个100倍； α-抑制因子III(Alpha1I3)，结构上的近亲IS 强劲下降。这两个基因的转录都受 糖皮质激素和白介素6(IL6)的作用方向相反。 我们已经分离并鉴定了这两个基因的DNA克隆 在Alpha1I3中找到了一个糖皮质激素反应元件 基因5‘侧翼区。我们已经确定了合适的大鼠肝癌 研究这两种基因在培养和培养过程中的调控 还分离了大鼠白细胞介素6的DNA克隆。这些将被用来 生产重组白介素6以定位白介素6反应对照 这两种基因的元素。 在这篇续集中，我们将描述顺式和反式动作的特征 这两个基因的控制元件负责通过 这两种荷尔蒙。将通过以下方式映射顺元素 在肝癌细胞或转基因小鼠中的转基因研究。这个 负责这两个基因的肝脏转录的元件将 通过肝细胞核提取液中的细胞外转录进行研究。 大鼠肝脏的独特可用性将被开发用于纯化 特定器官中相关反式因子的微克量 亲和层析。它们作为转录因子的功能 将通过突变和互补来建立。部分 这些因子的氨基酸序列将被确定并 相应的DNA克隆将被分离出来。对组织的研究 因子基因的特异性和发育调节将是 已启动。重组因子将在合适的 系统及其生化的初步表征 将尝试执行函数。 这项研究的目的是描述这些元素的特征 介导急性期基因转录的瞬时调控 并将它们与负责马厩的元素进行比较。 这些基因和其他基因的肝脏特异性表达。我们希望 了解急性期控制是否通过不同的 引起肝脏转录的相同元素的组合 或者它是否包含了本质上不同的元素。这是 试图通过专注于一种生化上可行的系统， 生物学上相关的并且已经很好地刻画了。改进 了解炎症介质对基因的调控可能 便于今后炎症控制物质的设计。

Acute phase proteins are produced by hepatocytes and are important in the defense against tissue damage and infections. Alpha2- macroglobulin (alpha2M), a broad range proteinase inhibitor, is increased several 100 fold-in acute and chronic inflammations; alpha-inhibitor III (alpha1I3), a close structural relative is strongly decreased. Transcription of both genes is controlled by glucocorticoids and interleukin 6 (IL6) in opposite directions. We have isolated and characterized DNA clones for both genes and have located a glucocorticoid responsive element in the alpha1I3 gene 5' flanking region. We have identified suitable rat hepatoma cell lines to study the regulation of both genes in culture and have also isolated rat IL6 DNA clones. These will be used to produce recombinant IL6 in order to map the IL6 responsive control elements of both genes. ln this continuation we will characterize the cis- and trans-acting control elements of both genes responsible for their regulation by these two hormones. The cis-elements will be mapped by transfection studies in hepatoma cells or transgenic mice. The elements responsible for hepatic transcription of both genes will be studied by cell free transcription in liver nuclear extracts. The unique availability of rat liver will be exploited to purify microgram amounts of relevant trans-factors by specific ORA affinity chromatography. Their function as transcription factors will be established by mutagenesis and complementation. Partial amino acid sequences of the factors will be determined and corresponding DNA clones will be isolated. Studies of the tissue specific and developmental regulation oF the factor genes will be initiated. Recombinant factors will be expressed in suitable systems and an initial characterization of their biochemical functions will be attempted. The purpose of this research is to characterize the elements mediating the transient control of acute phase gene transcription and to compare them with the elements responsible for the stable. liver specific expression of these and other genes. We wish to learn whether acute phase control is achieved by different combinations of the same elements that cause hepatic transcription or whether it involves qualitatively different elements. This is attempted by focusing on a system that is biochemically feasible, biologically relevant and already well characterized. Improved knowledge of gene regulation by inflammatory mediators may facilitate the future design of control substances of inflammation.