POSITIVE REGULATION OF INSULIN GENE TRANSCRIPTION

我们研究计划的最终目标是了解，在分子水平上， 术语，大鼠胰岛素II基因的所有顺式和反式作用元件 参与其在胰腺内的组织特异性表达 β细胞 尤其是我们试图理解积极的一面- 这个系统的组成部分。 我们最近对老鼠的特征进行了研究 胰岛素III基因5 ′-侧翼序列，包括其增强子。 我们 还示出了存在多个离散元件，其包括 该增强子是一个约10 bp的序列，位于 大鼠胰岛素基因II转录单位。 我们检测到一种DNA结合 蛋白质，它是唯一存在（活性）在胰岛素产生细胞， 与这个重要的调控序列特异性相互作用。 此外，最近我们已经鉴定并分离了两个lamda-gt 11-cDNA， 表达特异性结合所述抗体的融合蛋白的克隆 低聚的-100至-91元素。 我们建议进一步描述这些 顺式和反式作用组分， -100到-91元件，克隆编码它的基因，并研究它们的功能。 其促进胰岛素基因的作用机制 胰岛素基因的转录和表达调控 转录调节因子本身。 我们还将寻找更多的 胰岛素基因转录的反式作用因子 β细胞 一旦确定了这些因素， 与上文概述的通过-100至 -91元素。 了解胰岛素基因的调控机制 转录是获得全面，基本了解的基础， 葡萄糖稳态及其病理状态。

The ultimate goal of our research program is to understand, in molecular terms, all of the cis- and trans-acting elements of the rat insulin II gene which are involved in its tissue-specific expression within the pancreatic beta-cell. In particular we are attempting to understand the positive- acting components of this system. We have recently characterized the rat insulin III gene 5'-flanking sequences which encompass its enhancer. We have also shown that there are multiple, discrete elements which comprise this enhancer is an -10bp sequence located t positions -100 to -91 within the rat insulin gene II transcription unit. We have detected a DNA-binding protein, which is uniquely present (active) in insulin producing cells, that specifically interacts with this important regulatory sequence. Moreover, recently we have identified and isolated two lamda-gt11-cDNA clones which express a fusion protein which specifically binds to the oligomerized -100 to -91 element. We propose to further characterize these cis- and trans-acting components by purifying the factor which binds to the -100 to -91 element, cloning the gene which encodes it and studying both its mechanism of action regarding the promotion of insulin gene transcription and the regulation of expression of this insulin gene transcriptional regulator itself. We will also search for additional trans-acting factors which positively affect insulin gene transcription in beta-cells. Once this factors(s) has been identified it will be subjected to the analyses outlined above for the factor operating through the -100 to -91 element. Understanding the mechanism of regulation of insulin gene transcription is fundamental to gaining a thorough, basic understanding of glucose homeostasis and pathological states thereof.