Alpha-Myosin Heavy Chain Gene Repression & Heart Failure

描述(由申请人提供)：这项工作的总体目标 应用于确定α-MHC背后的分子机制 在心力衰竭期间发生的下调。最近从以下方面获得的数据 动物和人类都显示出α-MHC基因产物的相当大的损失。 然而，心力衰竭时α-MHC下调背后的机制 几乎仍然是未知的。最近，PI克隆并鉴定了一种 发挥基因抑制作用的单链DNA结合蛋白(PNRB) 抄写。有趣的是，PI发现PNRB不仅与 α-MHC基因的基本顺式调控元件，也与编码有关 α-MHC信使核糖核酸。对应于该编码的RNA寡核苷酸 区域有能力从心脏核中特异性地拉下PNRB 提取。此外，PNRB的细胞水平被发现非常高 在衰弱的心脏里。根据这些观察，公安局认为PNRB 起双重作用，同时损害转录和翻译调节 超负荷心脏中α-MHC基因的表达。在这项提案中，实验 旨在进一步探讨PNRB在控制中的意义 在心力衰竭期间α-MHC的表达。私家侦探将审查 PNRB参与α-MHC报告基因的转录和翻译。这个 PI还将分析PNRB在α-MHC中的生理意义 表达在片刻的心脏准备中，并对其收缩特性进行研究 一颗衰竭的心脏。

DESCRIPTION (provided by the applicant): The broad objective of this application is to determine the molecular mechanisms behind alpha-MHC down-regulation that occurs during heart failure. Recent data obtained from both animals and humans indicate a considerable loss of alpha-MHC gene product. However, the mechanism behind alpha-MHC down-regulation during heart failure remains virtually unknown. Recently, the PI has cloned and characterized a single-strand DNA-binding protein (PNRB) that plays a repressor role in gene transcription. Interestingly, the PI found that PNRB binds not only to an essential cis-regulatory element of the alpha-MHC gene but also to the coding region of alpha-MHC mRNA. The RNA oligonucleotide corresponding to this coding region has the ability to specifically pull down PNRB from cardiac nuclear extract. Furthermore, cellular levels of PNRB are found to be tremendously high in failing hearts. In light of these observations, the PI believes that PNRB plays a dual role, impairing both transcription and translational regulation of alpha-MHC gene expression in overloaded hearts. In this proposal, experiments have been designed to further explore the significance of PNRB in the control of alpha-MHC expression during heart failure. The PI will examine the role of PNRB in the transcription and translation of the alpha-MHC-reporter gene. The PI will also analyze the physiological significance of PNRB in alpha-MHC expression in a while heart preparation, and on the contractile characteristics of a failing heart.