Mechanism for Regulation of Phospholipase C by G Protein

G蛋白调节磷脂酶C的机制

• 批准号: 8401515
• 负责人: Alan V. Smrcka
• 金额: $ 30.26万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-30 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8401515
• 关键词: 1,2-diacylglycerol; A kinase anchoring protein; Ablation; Acute; Address; Adrenergic Receptor; Adult; Affect; Agonist; American; Angiotensin II; Animal Model; Arrhythmia; Binding; Biological Models; Buffers; Calcium; Cardiac; Cardiac Myocytes; Cardiac Output; Cell Fractionation; Cell Nucleus; Cells; Characteristics; Chest; Chronic; Complex; Coupled; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; DAG/PE-Binding Domain; Data; Development; Diagnosis; Diglycerides; Endothelin-1; Fluorescence Resonance Energy Transfer; Funding; GTP-Binding Proteins; Generations; Genes; Genetic; Goals; Guanosine Triphosphate Phosphohydrolases; Heart; Heart Hypertrophy; Heart failure; Hormones; Hydrolysis; Hypertrophy; Inositol; Insulin-Like Growth Factor I; Isoproterenol; Lead; Measures; Methods; Modeling; Molecular; Mus; Muscle; Muscle Cells; Myosin Heavy Chains; Nature; Neonatal; Nuclear; Nuclear Envelope; Pathogenesis; Pathway interactions; Pharmacological Treatment; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phospholipase C; Physiological; Process; Production; Protein Biosynthesis; Protein Isoforms; Proteins; Publishing; Rattus; Regulation; Regulatory Pathway; Role; RyR2; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum; Signal Pathway; Signal Transduction; Signaling Protein; Small Interfering RNA; Specific qualifier value; Stress; Tamoxifen; Ventricular; adenosine cyclic-3' ,5' -monophosphate binding proteins; base; constriction; cost; heart function; imaging modality; inhibitor/antagonist; mutant; novel; novel strategies; receptor; research study; response; rho; scaffold

DESCRIPTION (provided by applicant): Heart failure (HF) affects an estimated 4.7 million Americans, with approximately 550,000 new cases diagnosed annually and estimated annual costs ranging from $10 to $40 billion. One of the characteristics of progression to heart failure is reduced cardiac output due to decreased contractility and cardiac hypertrophy. We have identified a novel a cAMP-dependent pathway, involving the novel cAMP binding protein, Epac, and PLCe that increases cardiac calcium-induced calcium release (CICR) and ionotropic responses to ¿-adrenergic receptor (¿AR) stimulation. This pathway functions in physiological regulation of cardiac function and may also contribute to increased diastolic calcium release that underlies arrhythmogenesis during chronic adrenergic receptor stimulation. We will expand on this published discovery of a new PLCe dependent regulatory pathway in the heart by following new clues from our new exciting preliminary data on the importance of PLCe sub cellular scaffolding and signaling in regulation of both CICR and hypertrophy. The major focus is on I. understanding mechanisms underlying how sub cellular scaffolding of PLC5e may specify contractile vs. hypertrophic signaling, and II. Examining how PLCe can potentially integrate inputs from multiple signaling pathways by virtue of its unique ability to respond to multiple molecular signals. We will achieve these goals by exploring the following hypotheses: 1) Scaffolding to the Type II Ryanodine receptor (RyR2) and muscle A kinase anchoring protein (mAKAP) specifies distinct compartmentation of PLCe in cardiac cells. We found that PLCe forms complexes with both mAKAP and RyR2 in the heart. We hypothesize that mAKAP- and RyR2-complexed PLCe are separately compartmentalized pools in cardiac myocytes involved in regulation of hypertrophy and CICR, respectively. To address this idea we will examine the nature of the scaffold PLCe complexes and determine the roles of these complexes in cardiac function 2) Role of PLCe scaffolding in regulating hypertrophic signaling at the nucleus. We will explore the hypothesis developed in aim 1 that scaffolding PLCe in the heart specifies regulation of distinct functional Ca2+ signals involved in CICR in the SR, and inositol trisphosphate (IP3) dependent Ca2+ signals in the nucleus. We will also examine the role of scaffold PLCe in local diacylglycerol (DAG), PKC and PKD signals at the nucleus. We will also examine how PLCe can integrate multiple upstream signals to regulate these processes. 3) Mechanisms for PLCe- dependent regulation of cardiac hypertrophy. Preliminary data indicate that siRNA-dependent knockdown of PLCe inhibits protein synthesis stimulated by chronic ET-1 and Iso treatment in neonatal rat ventricular myocytes (NRVMs) suggesting PLCe involvement in cardiac hypertrophy, a marker for development of heart failure. We will explore these mechanisms further in a whole animal model system with cardiac myocyte specific deletion of PLCe.

描述（由申请人提供）：心力衰竭（HF）估计有470万美国人，每年诊断出约550,000例新病例，估计的年费用从10亿美元到400亿美元不等。由于收缩性和心脏肥大的降低，我们已经确定了一个无expectent的途径PAC，并且PLCE增加了心脏钙诱导的钙释放（CICR）和离子型对„的离子反应 - 肾上腺素受体（刺激。该途径在心脏功能的表现中起作用，也可能有助于增加慢性AdReceptor刺激期间的舒张钙的相对性化。f新的PLCE在心脏中的调节途径遵循我们对PLCE重要性的新令人兴奋的数据的线索，在某个时候，CICR和肥大的脚手架和信号。根据对多个分子信号的响应，我们将实现诱因假设：1）脚手架对II型ryanodine受体（RYR2）和肌肉锚固蛋白（MAKAP）指定PLSE在心脏细胞中的独特隔离。 e与心脏中的makap和ryr2形成复合物。劳力士在心脏功能中的作用2）在AIM 1中开发的假设在心脏中脚手架的假设指定了SR中CICR涉及的NAL的调节，而肌醇三磷酸盐（IP3）依赖于核中的CA2+信号。我们还将在局部检查局部二酰基甘油（DAG），PKC和PKD信号的作用数据表明，PLCE的siRNA依赖性敲低抑制了慢性ET-1和ISO治疗在新生大鼠心室心肌细胞（NRVM）中刺激的蛋白质合成，这表明PLCE参与心脏肥大，这是我们将进一步探索这些机制的标志。在整个动物模型系统中，PLCE的心肌细胞特异性缺失。