Modulation of Cav 1.3 L-type Ca2+ channels by PDZ-protein interactions

PDZ-蛋白质相互作用对 Cav 1.3 L 型 Ca2 通道的调节

• 批准号: 7798590
• 负责人: AMY LEE
• 金额: $ 34.55万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7798590
• 关键词: Action Potentials; Adult; Arrhythmia; Atrial Fibrillation; Binding; Biochemical; Biological Assay; Bradycardia; Brain; C-terminal; Calmodulin; Cardiac; Cardiac Myocytes; Cardiovascular system; Cells; Complex; Data; Development; Diabetes Mellitus; Drug abuse; Electrophysiology (science); Endocrine; Equilibrium; Event; Exhibits; Goals; Heart; Heart Atrium; Heart Rate; Immunochemistry; Mediating; Molecular; Molecular Biology; Mus; Nervous system structure; Neurons; Neurophysiology - biologic function; PDZ protein; Parkinson Disease; Peptides; Periodicity; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Physiological; Play; Process; Property; Protein Kinase C; Proteins; Protocols documentation; Recruitment Activity; Regulation; Research; Role; Screening procedure; Signal Transduction; Signaling Molecule; Sinoatrial Node; Site; Stimulus; Structure-Activity Relationship; Substantia nigra structure; Supraventricular Arrhythmia; Testing; Therapeutic; Tissues; alternative treatment; base; calmodulin-dependent protein kinase II; cell type; channel blockers; densin-180; design; dopaminergic neuron; effective therapy; in vivo; inhibitor/antagonist; insight; insulin secretion; neuroadaptation; neuronal excitability; novel; patch clamp; prevent; psychostimulant; public health relevance; receptor; response; scaffold; simulation; voltage

DESCRIPTION (provided by applicant): Voltage-gated L-type Ca2+ channels mediate Ca2+ signals that are essential for cardiac, endocrine, and neural functions. Although Cav1.2 is the predominant class of L-type channel in most tissues, Cav1.3 L-type channels play a major role in cardiac rhythmicity and neuronal excitability. Since small changes in Ca2+ influx can profoundly influence cellular excitability, factors that regulate Cav1.3 channels may control the balance between normal and diseased states of the nervous and cardiovascular systems. In screening for signaling molecules that specifically modulate Cav1.3, we discovered a novel regulation of these channels by interactions with proteins containing motifs known as PDZ-domains. The PDZ-protein, erbin, binds to the C-terminal domain (CT) of the 11-subunit (111.3) of Cav1.3 and dramatically enhances channel opening in response to depolarizing stimuli in a process termed voltage-dependent facilitation (VDF). A closely related protein, densin-180, also interacts with the 111.3 CT but does not influence VDF. Instead, densin-180 inhibits Ca2+-dependent inactivation of Cav1.3 and this effect depends on functional recruitment of calmodulin-dependent kinase II. Based on these findings, we hypothesize that Cav1.3 channels are fundamentally regulated by PDZ-protein interactions, which may diversify the signaling potential of these channels in different cell-types. The goal of this proposal is to characterize the molecular mechanism by which Cav1.3 channels are differentially modulated by such PDZ interactions, and the physiological significance of this regulation using molecular biology, immunochemistry, and electrophysiology. The proposed studies will clarify structure/function relationships and modulatory mechanisms that distinguish Cav1.3 from other L-type channels, which will broaden our understanding of the diverse physiological roles of Cav1.3 in regulating heart-rate, insulin secretion, and neural adaptations to psychostimulants. The long-term objective of this research is to gain molecular insights into the development of Cav1.3-selective drugs, which may provide novel and effective treatments for cardiac arrhythmias, diabetes, and drug abuse. PUBLIC HEALTH RELEVANCE: The proposed research will modulate voltage-gated Ca2+ channels. We will elucidate new structure/function relationships and modulatory mechanisms, which may be altered in diseased states of the cardiovascular and nervous systems.

描述（由申请人提供）：电压门控L型Ca2+通道介导Ca2+信号，这对于心脏，内分泌和神经功能至关重要。尽管CAV1.2是大多数组织中L型通道的主要类别，但CAV1.3 L型通道在心脏节奏和神经元兴奋性中起主要作用。由于CA2+流入的小变化会深刻影响细胞兴奋性，因此调节CAV1.3通道的因素可以控制神经和心血管系统正常状态和患病状态之间的平衡。在筛选特异性调节CAV1.3的信号分子时，我们通过与含有称为PDZ-域的蛋白质的蛋白质相互作用发现了这些通道的新调节。 PDZ蛋白ERBIN与CAV1.3的11-亚基（111.3）的C末端结构域（CT）结合，并在一个被称为电压依赖性辅导（VDF）的过程中对去极化刺激的响应，从而大大增强了通道的开口。密切相关的蛋白质Densin-180也与111.3 CT相互作用，但不影响VDF。取而代之的是，densin-180抑制了Ca2+依赖性cav1.3的失活，而这种作用取决于钙调蛋白依赖性激酶II的功能募集。基于这些发现，我们假设CAV1.3通道从根本上受到PDZ蛋白质相互作用的调节，这可能会使这些通道在不同细胞类型中的信号传导潜力多样化。该提案的目的是表征通过这种PDZ相互作用差异调节CAV1.3通道的分子机制，并使用分子生物学，免疫化学和电生理学来调节该调节的生理意义。拟议的研究将阐明将CAV1.3与其他L型通道区分开的结构/功能关系和调节机制，这将扩大我们对CAV1.3在调节心脏率，胰岛素分泌和神经适应心理刺激物中的生理作用的理解。这项研究的长期目标是获得对CAV1.3选择药物发展的分子见解，这可能为心律不齐，糖尿病和药物滥用提供新颖有效的治疗方法。公共卫生相关性：拟议的研究将调节电压门控CA2+通道。我们将阐明新的结构/功能关系和调节机制，在心血管和神经系统的患病状态中可能会改变。