Reprogramming of cardiac genome by Smyd1 in hypertrophy and failure

项目总结/摘要 现在认识到，基因组是动态的，并且DNA的选择性包装决定了基因组的结构。 细胞中不同基因组的表达。DNA包裹核小体及其组织 进入更高级的结构是从根本上影响染色质重塑酶。 这些酶 选择性地将核小体沿着DNA链定位，并通过以下方式影响组蛋白与DNA的相互作用： 修饰组蛋白的氨基末端尾部。 染色质结构的总体变化在发育过程中最为突出，并影响细胞命运 通过建立细胞类型特异性基因表达。 染色质结构的变化也被观察到 在疾病期间，染色质重塑酶的破坏与心脏肥大有关。 然而，我们需要一个清晰的图像来描述心脏中调节染色质结构的蛋白质网络 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。 虽然组蛋白的翻译后修饰（PTM）已经很好地建立，但酶 负责选择性地添加和删除这些监管标志的人才刚刚开始 表征了 一个新出现的组蛋白甲基转移酶（HMTs）家族被称为Smyd。 种系 肌肉限制性家族成员Smyd 1的缺失，由于心脏功能受损导致胚胎死亡。 分化 与这一观察结果相一致，肌肉前体细胞中Smyd 1的过度表达导致了 加速分化。 尽管这些有趣的见解Smyd 1在发展过程中的作用， 内源性定位、调节和在心脏病中的作用是未知的。 我的初步数据 证明心力衰竭期间Smyd 1丰度增加，并建立确定其 活性、细胞内定位和作用机制。 本申请的短期目标是了解Smyd 1在成人心肌中的作用， 来表征心力衰竭时的下游靶点。 该项目的长期目标是整合 这些概念来理解赋予心脏基因组中Smyd 1靶向特异性的因素。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，成像和下一代 第二代测序技术来推进我们对心力衰竭的理解。我们的方法将提供 对HMT的激活和调节以及赋予HMT的机制的基本见解， 基因组靶向的特异性。 对临床领域的意义在于提供一种机制 基因组如何随着疾病重新编程的基础，以便未来的干预措施可以针对特定的 染色质重塑事件。

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.