Regulation of RBM20 expression and activity in cardiac development and disease

RBM20 表达和活性在心脏发育和疾病中的调节

• 批准号: 271048839
• 负责人: Professor Dr. Michael Gotthardt
• 金额: --
• 依托单位: Forschungsgruppe Neuromuskuläre und kardiovaskuläre Zellbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/271048839?language=en
• 关键词: Regulation; RBM20; expression; activity; cardiac

Alternative splicing plays a major role in the regulation of gene expression and in the generation of proteome diversity. Lately it has been increasingly recognized that defects in splice factors as well as their target sites can cause human disease. Accordingly, alternative splicing has the potential to serve as a therapeutic target for various inherited diseases of the central nervous system, heart, and skeletal muscle. We have recently established RNA binding motif protein 20 (RBM20) as a regulator of cardiac splicing with a broad substrate spectrum that includes titin. Mutations in RBM20 result in severe forms of human dilated cardiomyopathy (DCM) with deregulation of several alternatively spliced transcripts that contribute to the disease state. As RBM20 modulates splicing of select substrates that orchestrate both electrical and mechanical cardiac function, an RBM20 directed therapy is expected to improve diverse aspects of cardiac pathology.The clinical relevance of RBM20 deficiency and its substrate spectrum have been described in the past five years and we are only beginning to understand its regulation on the RNA and protein level. Thus, little is known about the regulation of RBM20 expression, about the interactions of RBM20 with the basic splicing machinery, about the modulation of its splicing activity, and about the underlying mechanisms by which mutations in RBM20 contribute to cardiac pathology. To dissect the molecular functions of RBM20, to understand its regulation and to develop RBM20 as a therapeutic target, we propose the following aims:Aim 1: Regulation of RBM20 expressionHypothesis: The expression of RBM20 is spatially and temporally regulated to adapt titin isoform expression in developing and diseased striated muscleTest 1.1: Physiological RBM20 RNA and protein expression.Test 1.2: RBM20 levels in cardiac remodeling and disease.Test 1.3: Characterization of the human RBM20 promoter.Test 1.4: Pharmacological modulation of RBM20 transcript levels.Aim 2: Regulation of RBM20-mediated splicingHypothesis: RBM20 regulates alternative splicing through specific interactions with RNA and components of the splicing machineryTest 2.1: The molecular and mechanistic basis of RBM20-dependent splicing.Test 2.2: RBM20 protein domains involved in the regulation of alternative splicing.Aim 3: Functional consequences of RBM20 mutationsHypothesis: Mutations of RBM20 that are linked to DCM alter function, stability or localization of the proteinTest 3.1: Protein homeostasis of mutant RBM20.Test 3.2: Nuclear localization, RNA binding and splicing regulation of mutant RBM20.

选择性剪接在基因表达的调控和蛋白质组多样性的产生中起着重要作用。最近人们越来越认识到剪接因子及其靶位点的缺陷会导致人类疾病。因此，选择性剪接有可能作为中枢神经系统、心脏和骨骼肌的各种遗传性疾病的治疗靶点。我们最近建立了RNA结合基序蛋白20（RBM20）作为一个调节心脏剪接与广泛的底物谱，包括肌联蛋白。RBM20的突变导致严重形式的人类扩张型心肌病（DCM），并导致疾病状态的几种选择性剪接转录物失调。由于RBM20调节选择底物的剪接，协调电和机械心脏功能，RBM20定向治疗有望改善心脏病理学的各个方面，RBM20缺陷及其底物谱的临床相关性在过去五年中已被描述，我们才刚刚开始了解其在RNA和蛋白质水平上的调节。因此，人们对RBM 20表达的调节、RBM 20与基本剪接机制的相互作用、其剪接活性的调节以及RBM 20突变导致心脏病理学的潜在机制知之甚少。为了剖析RBM20的分子功能，理解其调节并开发RBM20作为治疗靶点，我们提出以下目的：目的1：RBM20表达的调节假设：RBM20的表达在空间和时间上受到调节，以适应发育和患病横纹肌中肌联蛋白同种型的表达测试1.1：生理RBM20 RNA和蛋白质表达测试1.2：RBM20在心脏重塑和疾病中的水平。试验1.3：人RBM20启动子的特性。试验1.4：RBM20转录水平的药理学调节。目的2：RBM20介导的剪接的调节。假设：RBM20通过与RNA和剪接机制的组分的特异性相互作用调节可变剪接。试验2.1：RBM20依赖性剪接的分子和机制基础。试验2.2：RBM20蛋白质结构域参与可变剪接的调节。目的3：RBM20突变的功能后果假设：与DCM相关的RBM20突变改变蛋白质的功能、稳定性或定位。试验3.1：突变型RBM20的蛋白质稳态。试验3.2：突变型RBM20的核定位、RNA结合和剪接调节。