GLUCOKINASE GENE EXPRESSION IN THE PANCREATIC BETA CELL

胰腺β细胞中的葡萄糖激酶基因表达

• 批准号: 2444044
• 负责人: MARK A MAGNUSON
• 金额: $ 16.87万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2444044
• 关键词: DNA footprinting; antisense nucleic acid; enzyme mechanism; enzyme structure; fusion gene; gene deletion mutation; gene expression; genetic promoter element; genetically modified animals; glucokinase; glucose metabolism; laboratory mouse; molecular cloning; neoplastic cell culture for noncancer research; pancreatic islet function; polymerase chain reaction; protein isoforms; protein purification; protein structure function; transcription factor; transfection; transposon /insertion element

DESCRIPTION: Glucokinase (GK), a high Km hexokinase, is a key component of the glucose sensing apparatus of pancreatic beta cells and mutations in the human glucokinase gene are linked to the development of Maturity Onset Diabetes of Youth (MODY), an early onset form of NIDDM. While the GK gene has been established as one of only a few authentic diabetes genes, it is not understood how mutations in this gene actually cause hyperglycemia. Recent data suggests that the current notion that hyperglycemia in GK-deficient NIDDM is due primarily to a glucose sensing defect by the beta cell is overly simplistic. First, they have identified GK in extrapancreatic neural and neuroendocrine cells that, like pancreatic beta cells, may also be able to sense fluxes in glucose concentration. Second, GK ribozyme transgenic mice that have reduced amounts of GK in the beta cells are less severely affected than might have been predicted. Additional studies are necessary, therefore, to understand more about the cell-specific expression and function of GK in extrapancreatic neural and neuroendocrine cells and the pathogenesis of GK- deficient NIDDM. Four complementary Specific Aims are proposed: Specific Aim 1. Produce and characterize transgenic mice that contain copies of an 83 kb fragment of the mouse glucokinase gene and test the ability of the transgene to rescue the lethal embryonic phenotype observed with the total knock-out of the glucokinase gene. Specific Aim 2. Use a strategy of targeted oncogenesis in transgenic mice to identify and characterize extrapancreatic neuroendocrine cells that express the islet glucokinase isoform. Specific Aim 3. Identify and characterize negatively-acting cis-regulatory elements, and their binding protein(s), that repress expression of the upstream glucokinase promoter. Specific Aim 4. Establish a model system in which glucokinase can be conditionally removed from different cell types of the mouse with initial emphasis being placed on eliminating glucokinase in pancreatic beta cells.

描述：葡萄糖激酶（GK）是一种高Km的己糖激酶，是一种关键成分， 胰腺β细胞的葡萄糖感应装置和突变 在人类葡萄糖激酶基因的发展与成熟 青年发病型糖尿病（MODY）是NIDDM的一种早期发病形式。而 GK基因已被确定为仅有的几个真正的糖尿病之一 基因，目前还不清楚该基因的突变如何导致 高血糖症最近的数据表明，目前的概念， GK缺陷型NIDDM的高血糖主要是由于葡萄糖 β细胞的检测缺陷过于简单化。一是 在胰腺外神经和神经内分泌细胞中鉴定出GK， 像胰腺β细胞一样，也可能能够感知葡萄糖的流动， 浓度.第二，GK核酶转基因小鼠， β细胞中的GK含量受到的影响比可能的要小， 已经被预测。因此，需要进行更多的研究， 了解更多关于GK的细胞特异性表达和功能， 胰腺外神经和神经内分泌细胞与胰腺炎发病机制 GK缺陷型NIDDM。提出了四个互补的具体目标： 具体目标1。生产和表征转基因小鼠， 拷贝的小鼠葡糖激酶基因的83 kb片段，并测试 转基因拯救致死胚胎表型的能力 观察到葡萄糖激酶基因的完全敲除。具体目标 2.使用转基因小鼠中的靶向肿瘤发生策略来鉴定 并表征胰腺外神经内分泌细胞， 胰岛葡萄糖激酶亚型。具体目标3。识别和表征 负作用顺式调节元件，及其结合蛋白， 其抑制上游葡糖激酶启动子的表达。具体 目标4。建立葡萄糖激酶可条件性 从小鼠的不同细胞类型中取出， 用于消除胰腺β细胞中的葡萄糖激酶。