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.

心脏对慢性应激的反应涉及心肌细胞信号转导网络的激活，该网络在 疾病促进病理性心脏重塑和心力衰竭。在这些细胞和 病理生理变化是决定心脏表型的基因转录的改变。 IIa类 组蛋白脱乙酰酶是转录抑制因子，其核输出与诱导 病理性重塑。这些 HDAC 受到多种功能相反的翻译后调节 修饰，包括 PKD 和 PKA 的磷酸化，分别促进核输出和核输入。 支架蛋白 mAKAPβ 协调心肌细胞中病理性心脏病所需的信号传导 重塑。而 HDAC5 核输出需要 mAKAPβ 结合的 PKD 来响应 α-肾上腺素能 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-肾上腺素能 (βAR) 抑制该过程。然而，βAR 信号传导促进 IIa 类 HDAC 保留在细胞核中， 仅在急性βAR刺激时。疾病中存在的慢性 βAR 刺激导致 HDAC5 核 输出，也是通过 mAKAPβ 依赖机制。在这个项目中，我们将研究双向控制 mAKAPβ 信号体对 IIa 类 HDAC 进行磷酸化和核输出。我们建议将此切换 信号传导部分归因于 PKA 诱导型蛋白磷酸酶 2A (PP2A) 和盐诱导型蛋白磷酸酶 2A (PP2A) 的存在 mAKAPβ 信号小体中的激酶 I (SIK1) 活性。具体目标 1：mAKAPβ - IIa 类 HDAC 的要求 病理重塑复合体。在这个目标中，我们将表征 mAKAPβ-的结构和功能 含有 HDAC5 和 HDAC 目标 MEF2D 的复合物，以及它们对儿茶酚胺的重要性 体外诱导成体肌细胞肥大。使用腺相关病毒将干扰肽递送至 在体内的心肌细胞中，我们将测试抑制复合物的形成是否会阻止病理性的发生。 压力超负荷引起的重塑和心力衰竭。具体目标 2：阐明机制 mAKAPβ 依赖性 β-肾上腺素能抑制 HDAC5 核输出。使用特定的 mAKAP 突变体 蛋白和锚定破坏蛋白，我们将剖析 PKA 依赖性 HDAC5 的相对作用 mAKAPβ 的磷酸化和 PP2A 激活抑制 GqPCR 诱导的 HDAC5 核输出。具体的 目标 3：HDAC 核输出和病理重塑对 SIK1 的要求。我们现在透露 HDAC 激酶 SIK1 结合 mAKAPβ，并且 mAKAPβ 结合的 PKA 是肌细胞中 SIK1 诱导所必需的。 我们将研究 SIK1 及其被 mAKAPβ 结合的 PKA 磷酸化是否是 HDAC5 核所必需的 体外输出并使用条件敲除测试 SIK1 与体内成体心肌细胞的相关性 鼠标模型。这些目标将阐明 mAKAPβ 信号体如何双向协调 IIa 型 HDAC 在肌细胞中发挥作用。此外，该项目将揭示mAKAPβ信号体的靶向调控如何 HDAC 在预防心脏重塑和心力衰竭方面具有治疗作用。