Alpha-Myosin Heavy Chain Gene Repression & Heart Failure

描述（由申请人提供）：本申请的广泛目标 应用是确定α-MHC背后的分子机制 在心力衰竭期间发生的下调。最近的数据来自 动物和人都表明α-MHC基因产物的相当大的损失。 然而，心力衰竭时α-MHC下调的机制 仍然是个未知数最近，PI克隆并鉴定了一种 一种单链DNA结合蛋白（PNRB），在基因中起阻遏作用 转录。有趣的是，PI发现PNRB不仅结合于 重要的顺式调控元件的α-MHC基因，而且编码 α-MHC mRNA的区域。对应于该编码的RNA寡核苷酸 该区域具有特异性地将PNRB从心脏核中拉下的能力 提取物此外，发现PNRB的细胞水平非常高， 在衰竭的心脏中。根据这些观察结果，PI认为PNRB 起着双重作用，损害转录和翻译调节， 超负荷心脏中的α-MHC基因表达。在这项研究中，实验 旨在进一步探讨PNRB在控制 在心力衰竭期间的α-MHC表达。主要研究者将审查以下人员的角色 PNRB在α-MHC报告基因的转录和翻译中的作用。的 PI还将分析PNRB在alpha-MHC中的生理意义 表达在一段时间的心脏制备中，并对收缩特性进行了研究 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.