Alpha-Myosin Heavy Chain Gene Repression & Heart Failure

描述（由申请人提供）：本项目的总体目标 应用是确定 α-MHC 背后的分子机制 心力衰竭期间发生的下调。最近的数据来自 动物和人类都表明 α-MHC 基因产物大量损失。 然而，心力衰竭期间 α-MHC 下调背后的机制 仍然几乎不为人所知。最近，PI 克隆并表征了 在基因中发挥抑制作用的单链 DNA 结合蛋白 (PNRB) 转录。有趣的是，PI 发现 PNRB 不仅与 α-MHC 基因的重要顺式调节元件，也是编码的重要元件 α-MHC mRNA 区域。与该编码对应的RNA寡核苷酸 该区域具有从心脏核中特异性拉下 PNRB 的能力 提取物。此外，PNRB 的细胞水平被发现非常高 在失败的心中。根据这些观察结果，PI 认为 PNRB 发挥双重作用，损害转录和翻译调节 超负荷心脏中的 α-MHC 基因表达。在这个提案中，实验 旨在进一步探讨PNRB在控制中的意义 心力衰竭期间 α-MHC 表达的影响。 PI 将审查以下角色的作用： PNRB 参与 α-MHC 报告基因的转录和翻译。的 PI还将分析PNRB在α-MHC中的生理意义 心脏准备期间的表达以及收缩特性 一颗失败的心。

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.