Regulation of Histone Deacetylases by mAKAP Signalosomes

mAKAP 信号小体对组蛋白脱乙酰酶的调节

• 批准号: 10308025
• 负责人: Kimberly L Dodge-Kafka
• 金额: $ 53.02万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-15 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10308025
• 关键词: A kinase anchoring protein; Acute; Adrenergic Agents; Adult; Apoptosis; Binding; Binding Proteins; Cardiac; Cardiac Myocytes; Catecholamines; Cell Nucleus; Chronic; Chronic stress; Complex; Coupled; Cyclic AMP-Dependent Protein Kinases; Data; Dependovirus; Diagnosis; Disease; Enzymes; Event; Fibrosis; Functional disorder; G alpha q Protein; Gene Expression; Genetic Transcription; HDAC5 gene; Heart failure; Histone Deacetylase; Holoenzymes; Hypertrophy; In Vitro; Knockout Mice; Modeling; Muscle; Muscle Cells; Muscle Proteins; Muscle function; Myocardial; Neonatal; Neurosecretory Systems; Nuclear Export; Nuclear Import; Operative Surgical Procedures; Pathologic; Pathway interactions; Peptides; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiological; Post-Translational Protein Processing; Prevention; Process; Protein phosphatase; Proteins; Publishing; Rattus; Regimen; Regulation; Role; Scaffolding Protein; Signal Transduction; Site; Stress; Structure; Syndrome; Testing; Therapeutic; Transcription Repressor; Ventricular; Ventricular Remodeling; alpha-adrenergic receptor; base; cardiogenesis; conditional knockout; constriction; in vitro testing; in vivo; interstitial; mortality; mouse model; mutant; pressure; prevent; protein B; protein kinase D; receptor; response; salt-inducible kinase; scaffold

The cardiac response to chronic stress involves the activation of a myocyte signal transduction network that in disease promotes pathological cardiac remodeling and heart failure. Underlying these cellular and pathophysiological changes is the altered transcription of genes that determine cardiac phenotype. Class IIa histone deacetylases are transcriptional repressors whose nuclear export is associated with the induction of pathological remodeling. These HDACs are regulated by multiple, functionally opposing post-translational modifications, including phosphorylation by PKD and PKA that promote nuclear export and import, respectively. The scaffold protein mAKAPβ orchestrates signaling in the cardiac myocyte required for pathological cardiac remodeling. Whereas mAKAPβ-bound PKD was required for HDAC5 nuclear export in response to α-adrenergic receptor stimulation of cultured neonatal rat ventricular myocytes, mAKAPβ-bound PKA conferred β-adrenergic (βAR) inhibition of that process. βAR signaling promoting class IIa HDAC retention in the nucleus is, however, only upon acute βAR stimulation. Chronic βAR stimulation as present in disease resulted in HDAC5 nuclear export, also by a mAKAPβ-dependent mechanism. In this project, we will investigate the bidirectional control of class IIa HDAC phosphorylation and nuclear export by mAKAPβ signalosomes. We propose that this switch in signaling is due in part to the presence of PKA-inducible protein phosphatase 2A (PP2A) and salt-inducible kinase I (SIK1) activity in mAKAPβ signalosomes. Specific Aim 1: Requirement for mAKAPβ - class IIa HDAC complexes in pathological remodeling. In this Aim we will characterize the structure and function of mAKAPβ- complexes containing HDAC5 and the HDAC target MEF2D, as well as their importance for catecholamine- induced hypertrophy of adult myocytes in vitro. Using adeno-associated virus to deliver the disruptor peptide to the cardiac myocyte in vivo, we will test whether inhibited complex formation will prevent the pathological remodeling and heart failure induced by pressure overload. Specific Aim 2: Elucidation of the mechanism for mAKAPβ-dependent β-adrenergic inhibition of HDAC5 nuclear export. Using specific mAKAP mutant proteins and anchoring disruptor proteins, we will dissect the relative roles of PKA-dependent HDAC5 phosphorylation and PP2A activation at mAKAPβ in inhibiting GqPCR-induced HDAC5 nuclear export. Specific Aim 3: Requirement for SIK1 in HDAC nuclear export and pathological remodeling. We now reveal that the HDAC kinase SIK1 binds mAKAPβ and that mAKAPβ-bound PKA is required for SIK1 induction in myocytes. We will study whether SIK1 and its phosphorylation by mAKAPβ-bound PKA is required for HDAC5 nuclear export in vitro and test the relevance of SIK1 to the adult cardiac myocyte in vivo using a conditional knock-out mouse model. These Aims will elucidate how mAKAPβ signalosomes bidirectionally coordinate type IIa HDAC function in myocytes. In addition, this project will reveal how targeting of mAKAPβ signalosome regulation of HDACs can be therapeutically beneficial in the prevention of cardiac remodeling and heart failure.

对慢性应激的心脏反应涉及在 疾病促进病理心脏重塑和心力衰竭。这些细胞和 病理生理变化是决定心脏表型的基因的转录改变。 IIA级 Hisstone脱乙酰基酶是转录表示，其核出口与诱导有关 病理重塑。这些HDAC由多个功能相反的翻译后调节 修饰，包括分别促进核出口和进口的PKD和PKA的磷酸化。 脚手架蛋白Makapβ在病理心脏中策划了心肌的信号传导 重塑。而HDAC5核导出需要α-肾上腺素的HDAC5核输出需要 培养的新生大鼠心室肌细胞的受体刺激MAKAPβ结合的PKA赋予β-肾上腺素 （βAR）抑制该过程。但是 仅在急性βAR刺激下。疾病中存在的慢性βAR刺激导致HDAC5核 出口，也是通过makapβ依赖机制的。在这个项目中，我们将研究的双向控制 IIA类HDAC磷酸化和MAKAPβ信号体的核输出。我们建议此切换 信号传导部分归因于PKA诱导的蛋白磷酸酶2a（PP2A）和盐诱导 MAKAPβ信号体中的激酶I（SIK1）活性。特定目标1：MAKAPβ-IIA类HDAC的要求 病理重塑中的复合物。在此目标中，我们将表征makapβ-的结构和功能 含有HDAC5和HDAC靶标MEF2D的复合物，以及它们对Catecholamine-的重要性 在体外诱导成年肌细胞的肥大。使用腺相关病毒将破坏者肽传递到 心肌在体内，我们将测试抑制的复合形成是否会阻止病理 压力超负荷引起的重塑和心力衰竭。特定目的2：阐明机制 MAKAPβ依赖性的β-肾上腺素能抑制HDAC5核输出。使用特定的makap突变体 蛋白质和锚定破坏蛋白，我们将剖析依赖PKA的HDAC5的相对作用 MAKAPβ的磷酸化和PP2A激活在抑制GQPCR诱导的HDAC5核输出方面。具体的 目标3：在HDAC核出口和病理重塑中对SIK1的要求。我们现在透露 HDAC激酶SIK1结合makapβ，肌细胞中SIK1诱导需要MAKAPβ结合的PKA。 我们将研究SIK1是否需要HDAC5核的SIK1及其磷酸化。 体外导出并测试Sik1使用条件敲除的体内成人心肌细胞的相关性 鼠标模型。这些目的将阐明makapβ信号体如何双向坐标IIA型HDAC 在肌细胞中的功能。此外，该项目将揭示Makapβ信号体调节的靶向 HDAC可以对预防心脏重塑和心力衰竭有热有益。