REGULATED EXPRESSION OF CATECHOLAMINE BIOSYNTHESIS GENES

儿茶酚胺生物合成基因的调控表达

• 批准号: 6385691
• 负责人: Elaine J. Lewis
• 金额: $ 23.25万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6385691
• 关键词: DNA binding protein; biosynthesis; catecholamines; crosslink; cyclic AMP; dopamine beta monooxygenase; enzyme activity; enzyme induction /repression; gene expression; genetic regulation; genetic regulatory element; genetic transcription; immunoprecipitation; intermolecular interaction; laboratory rat; neurons; neurotransmitter biosynthesis; norepinephrine; phosphorylation; polymerase chain reaction; protein kinase A; protein structure function; tissue /cell culture; transcription factor; tyrosine 3 monooxygenase

The overall focus of this proposal is to delineate the molecular and genetic events which lead to the regulated expression of the neuroendocrine genes tyrosine hydroxylase (TH) and dopamine beta-hydroxylase. TH is the initial and rate limiting enzyme in the biosynthesis of dopamine, norepinephrine and epinephrine, and DBH catalyzes the conversion of dopamine to norepinephrine. TH and DBH are co-expressed in noradrenergic and adrenergic cells, and the expression of the TH and DBH genes are frequently coordinately regulated by environmental, neuronal and hormonal influences. This ongoing research program has identified several of the genetic regulatory elements which control the transcription of the TH and DBH genes, as well as the transcription factors which interact with the regulatory elements to control the rate of transcription. In this current proposal, we will utilize biochemical, molecular biology and cellular approaches to: (l) investigate how second messengers and protein kinase cascades interact with the tissue specific transcription factor Phox2a/Arix to influence transcription of the TH and DBH genes through analysis of Arix phosphorylation, (2) identify and characterize the proteins which repress DBH gene expression in inappropriate tissues, and (3) evaluate the interaction of transcription factors Phox2a/Arix, Phox2b/NBPhox, CREB/ATF and AP1 with the TH and DBH genes within intact cells. These experiments will define the mechanisms by which tissue specific transcription factors interact with ubiquitous factors to mediate selective expression of the TH and DBH genes. Knowledge of the mechanisms underlying the regulated expression of these genes is relevant to studies where dopaminergic cells are lost, such as Parkinson's disease, and where aberrant balance of neurotransmitters lead to disease, such as hypertension and bipolar mental disorders.

该提案的总体重点是描述导致神经内分泌基因酪氨酸羟化酶（TH）和多巴胺β-羟化酶表达调节的分子和遗传事件。 TH 是多巴胺、去甲肾上腺素和肾上腺素生物合成的起始酶和限速酶，DBH 催化多巴胺转化为去甲肾上腺素。 TH 和 DBH 在去甲肾上腺素能和肾上腺素能细胞中共表达，并且 TH 和 DBH 基因的表达经常受到环境、神经元和激素影响的协调调节。这项正在进行的研究计划已经确定了一些控制 TH 和 DBH 基因转录的遗传调控元件，以及与调控元件相互作用以控制转录速率的转录因子。 在当前的提案中，我们将利用生化、分子生物学和细胞方法来：(l) 研究第二信使和蛋白激酶级联如何与组织特异性转录因子 Phox2a/Arix 相互作用，通过分析 Arix 磷酸化来影响 TH 和 DBH 基因的转录，(2) 识别和表征在不适当的组织中抑制 DBH 基因表达的蛋白质，以及 (3)评估转录因子Phox2a/Arix、Phox2b/NBPhox、CREB/ATF和AP1与完整细胞内TH和DBH基因的相互作用。这些实验将定义组织特异性转录因子与普遍存在的因子相互作用以介导 TH 和 DBH 基因选择性表达的机制。了解这些基因表达调节的机制与多巴胺能细胞丢失（例如帕金森病）以及神经递质平衡异常导致疾病（例如高血压和双相情感障碍）的研究相关。