Reprogramming of cardiac genome by Smyd1 in hypertrophy and failure

项目摘要/摘要 现在人们意识到基因组是动态的，DNA的选择性包装支配着 一组不同的基因在细胞中的表达。DNA包裹在核小体周围及其组织 进入高阶结构从根本上是受染色质重塑酶的影响。这些酶 通过以下方式选择性地沿DNA链定位核小体并影响组蛋白与DNA的相互作用 修饰组蛋白的氨基末端。 染色质结构的大体变化在发育过程中最为突出，并影响细胞的命运 通过建立特定细胞类型的基因表达。还观察到染色质结构的变化。 在疾病和染色质破坏期间，重塑酶与心肌肥厚有关。 然而，需要对心脏中调节染色质结构的蛋白质网络有一个清晰的了解。 了解疾病期间基因表达是如何在全基因组范围内重新编程的。 尽管组蛋白的翻译后修饰(PTM)已经得到了很好的证实，但酶 负责有选择地添加和删除这些监管标志的工作才刚刚开始 特色化的。一个新出现的组蛋白甲基转移酶(HMTs)家族称为SMID。生殖系 肌肉受限家族成员Smyd1的缺失导致心脏受损导致胚胎死亡 差异化。与此观察一致的是，在肌肉前体细胞中过表达Smyd1导致了 加快了差异化。尽管对Smyd1在开发过程中的作用有这些耐人寻味的见解，但它的 内源性在心脏疾病中的定位、调节和作用尚不清楚。我的初步数据 证明心力衰竭期间Smyd1的丰度增加，并建立确定其 这一应用中的活性、细胞内定位和作用机制。 该应用的短期目标是了解Smyd1在成人心肌和心肌中的作用。 以确定其在心力衰竭期间的下游靶点。这个项目的长期目标是整合 这些概念有助于理解赋予心脏基因组中Smyd1靶向性的因素。这 应用程序利用最先进的蛋白质组学、动物生理学、生物化学、成像和Next 世代测序技术，以促进我们对心力衰竭的理解。我们的方法将提供 对HMT的激活和调节的基本见解以及授予 他们以基因组为靶标的特异性。对临床领域的意义是提供了一种机械性的 为基因组如何与疾病重新编程奠定基础，以便未来的干预可以针对特定的 染色质重塑事件具有治疗性。

PROJECT SUMMARY/ABSTRACT It is now appreciated that genomes are dynamic and that selective packing of DNA governs the expression of distinct sets of genes in a cell. The wrapping of DNA around nucleosomes and its organization into higher order structures is fundamentally influenced by chromatin remodeling enzymes. These enzymes selectively position nucleosomes along the DNA strand and influence the interaction of histones with DNA by modifying the amino terminal tails of histones. Gross changes in chromatin structure are most prominent during development and influence cell fate by establishing cell-type-specific gene expression. Changes in chromatin structure have also been observed during disease and disruption of chromatin remodeling enzymes has been implicated in cardiac hypertrophy. However, a clear picture of the protein networks that modulate chromatin architecture in the heart is needed to understand how gene expression is reprogrammed on a genome-wide scale during disease. Although the post-translational modification (PTM) of histones has been well established, the enzymes responsible for the selective addition and removal of these regulatory marks have only begun to be characterized. A newly emerging family of histone methyltransferases (HMTs) is called Smyd. Germline deletion of the muscle-restricted family member, Smyd1, leads to embryonic lethality due to impaired cardiac differentiation. Consistent with this observation, overexpression of Smyd1 in muscle precursor cells led to accelerated differentiation. Despite these intriguing insights into the role of Smyd1 during development, its endogenous localization, regulation and role in cardiac disease are unknown. My preliminary data demonstrate increased Smyd1 abundance during heart failure and establish the approaches to determine its activity, intracellular localization and mechanisms of action in this application. The short term goal of this application is to understand the role of Smyd1 in the adult myocardium and to characterize its downstream targets during heart failure. The long term goal of this project is to integrate these concepts to understand the factors that confer targeting specificity to Smyd1 in the cardiac genome. This application leverages state-of-the-art proteomics, animal physiology, biochemistry, imaging and next generation sequencing technology to advance our understanding of heart failure. Our approach will provide fundamental insights into the activation and regulation of HMTs, as well as the mechanisms that confer specificity in their targeting of the genome. The significance to the clinical realm is to provide a mechanistic basis for how the genome is reprogrammed with disease, such that future interventions can target specific chromatin remodeling events therapeutically.