HORMONAL REGULATION OF ETHANOL METABOLISM

乙醇代谢的激素调节

• 批准号: 2042952
• 负责人: ESTEBAN MEZEY
• 金额: $ 33.43万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-06-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2042952
• 关键词: ADP ribosylation; DNA damage; DNA directed RNA polymerase; NAD nucleosidase; acetaldehyde; alcohol dehydrogenase; binding proteins; collagen; ethanol; gene expression; genetic crossing over; genetic enhancer element; genetic promoter element; genetic regulatory element; genetic transcription; histones; hormone regulation /control mechanism; laboratory rat; liver cells; liver metabolism; nonhistone nucleoprotein; nucleolus; protein sequence; somatotropin; tissue /cell culture; transfection; vasopressins

The objectives of the proposal are: 1) To investigate the mechanisms by which growth hormone (GH) regulates the expression of the rat class I alcohol dehydrogenase (ADH) gene and 2) To study the effects of ethanol on the ADP ribosylation of hepatocyte nuclear proteins as it relates to the effects of ethanol and/or acetaldehyde on DNA damage, DNA synthesis and gene expression. Proteins from rat liver nuclear extracts bound to 3 regions of the rat ADH promoter, designated as 1, 2, and 3 corresponding to positions -2 to -18, -36 to -44 and -52 to -60 relative to the start-site of transcription. CCAAT/enhancer binding protein (C/EBP) is one of the nuclear proteins that binds to region 1, and additional factors that interact with this site will be investigated. Region 2 has the binding sequence for a protein that functions cooperatively with the glucocorticoid receptor and will not be studied further. Region 3 appears to interact with the protein upstream regulatory factor and this interaction will be characterized further. The cis-acting element(s) within the ADH promoter that are required for GH to act will be determined by transfection experiments in both primary heptocyte culture and HepG2 cells using ADH promoter constructs. Lastly, the effect of GH on candidate protein(s) responsible for regulating expression of the ADH gene will be examined directly. Studies in the second objective of the proposal will determine the time course and reversibility of ethanol-induced enhancement of poly (ADP-ribose) polymerase activity and ADP-ribosylation of proteins in hepatocyte culture, and the role of these changes in the inhibitory effect of ethanol on DNA synthesis. Study of mechanisms for the ethanol-induced increase in poly (ADP-ribose) polymerase will concentrate on whether it is a consequence of ethanol or acetaldehyde induced mutagenicity as evidenced by sister-chromatid exchanges or DNA strand breaks or results from activation of poly (ADP-ribose) glycohydrolase which removes poly (ADP- ribose) residues from poly (ADP-ribose) polymerase reversing inhibition caused by autoribosylation. Histone and non-histone proteins whose ribosylation is augmented by ethanol will be identified. The binding of histone H1 to the alpha2(I) collagen promoter and the effect of its ribosylation on the binding to and expression of this collagen gene will be studied.

该提案的目标是：1）调查机制 哪种生长激素（GH）调节大鼠I类的表达 酒精脱氢酶（ADH）基因和2）研究乙醇对乙醇的影响 肝细胞核蛋白的ADP核糖基化与 乙醇和/或乙醛对DNA损伤，DNA合成和 基因表达。 大鼠肝核提取物的蛋白质结合到3 大鼠ADH启动子的区域，指定为1、2和3 位置-2至-18，-36至-44和-52至-60相对于起始站点 转录。 CCAAT/增强剂结合蛋白（C/EBP）是 与区域1结合的核蛋白质以及其他因素 将研究与此站点的互动。 区域2具有结合 与糖皮质激素合作起作用的蛋白质序列 受体，不会进一步研究。 区域3似乎相互作用 随着蛋白质上游调节因素，这种相互作用将是 进一步表征。 ADH启动子内的顺式作用元件 GH采取行动所必需的将由转染确定 使用ADH进行原代征肠细胞培养和HEPG2细胞的实验 启动子结构。 最后，GH对候选蛋白的影响 负责调节ADH基因的表达 直接地。 提案的第二个目标中的研究将决定 乙醇诱导的多聚的时间过程和可逆性 （ADP-核糖）聚合酶活性和蛋白质中蛋白质的ADP-核糖基化 肝细胞培养以及这些变化在抑制作用中的作用 乙醇在DNA合成中的含量。 研究乙醇诱导的机制 聚（ADP-核糖）聚合酶的增加将集中于它是否是 乙醇或乙醛引起的诱变性的结果如证明 通过姐妹 - 染色剂交换或DNA链断裂或从 去除聚（ADP- 来自聚（ADP-核糖）聚合酶反向抑制的核糖）残基 由自质基化引起。 组蛋白和非历史蛋白的蛋白 乙醇将增强核糖基化。 结合 组蛋白H1与α2（i）胶原蛋白启动子及其效果 在该胶原基因的结合和表达上的核糖基化将是 研究。