TISSUE SPECIFIC CNTRL ALPHA 1B ANDRENOCEPTOR EXPRESSION

描述：alpha 1B肾上腺素能受体（alpha 1BAR）是一种 G-蛋白偶联受体，在控制 心血管稳态和代谢过程中的肝脏，和最近 研究表明，不同的转录调控， alpha 1BAR基因在心脏和肝脏中的表达。 高博士 将测试假设，这种差异调节可能是由于 组织特异性调节相同转录因子的作用，或 基因与不同组织特异性转录的相互作用 因素 核因子1（NF 1）激活由转录因子驱动的转录。 Hep 3B细胞中α 1BAR基因的显性P2启动子和原代 肝细胞，但在DDT 1 MF-2细胞中抑制它。 这种双重性可能是由于 通过细胞特异性辅因子调节NF 1的活性。 这些 辅因子将通过使用酵母双杂交系统来鉴定。 的 NF 1的组织分布与2.7 kb的相对丰度平行， α 1BAR mRNA种类，除了心脏，其表达高水平的 α 1BAR和它的2.7kb mRNA，但很少（如果有的话）NF 1。 这表明 心脏中alpha 1BAR基因的转录涉及除以下因素之外的因素： NF 1。 事实上，DNA酶I足迹和DNA凝胶迁移率变化分析 显示P2启动子内的-721至-723区域结合一个新的， 以前未鉴定的转录因子，称为HF，在心脏。 这 因子将被进一步表征，通过DNA亲和纯化， 层析，如果需要的话，进行克隆。 这一因素在 转录控制将通过突变和转染来鉴定 分析。 参与细胞类型特异性辅因子的鉴定 NF 1和心脏特异性转录因子的调节功能 参与心脏中alpha 1BAR基因转录的基因将揭示 组织特异性调控的分子机制 α 1BAR基因表达。

DESCRIPTION: The alpha1B adrenergic receptor (alpha1BAR) is a G-protein-coupled receptor that plays an important role in the control of cardiovascular homeostasis and metabolic processes in the liver, and recent studies have shown differential regulation of the transcription of the alpha1BAR gene in heart and liver under a variety of conditions. Dr. Gao will test the hypothesis that this differential regulation may be due to the tissue specific modulation of the action of the same transcription factor or to the interaction of the gene with different, tissue-specific transcription factors. Nuclear factor 1 (NF1) activates transcription driven by the dominant P2 promoter of the alpha1BAR gene in Hep3B cells and primary hepatocytes, but inhibits it in DDT1MF-2 cells. This duality may be due to modulation of the activity of NF1 by cell-specific cofactors. These cofactors will be identified by using the yeast two-hybrid system. The tissue distribution of NF1 parallels the relative abundance of the 2.7-kb alpha1BAR mRNA species, except for the heart, which expresses high levels of alpha1BAR and its 2.7 kb mRNA but little, if any, NFl. This suggests that transcription of the alpha1BAR gene in heart involves factor(s) other than NF1. Indeed, DNase I footprinting and DNA gel mobility shift analyses showed that the region -721 to -723 within the P2 promoter binds a new, previously unidentified transcription factor, called HF, in heart. This factor will be further characterized, purified by DNA affinity chromatography and cloned, if necessary. The role of this factor in transcription control will be identified by mutational and transfection analyses. Identification of the cell type-specific cofactors involved in modulating function of NF1 and the cardiac-specific transcription factors involved in the transcription of alpha1BAR gene in heart will shed light on the molecular mechanisms involved in the tissue specific regulation of alpha1BAR gene expression.