AKAP Anchored PKA and Calcineurin Regulation of Neuronal L-type Calcium Channels

AKAP 锚定 PKA 和钙调磷酸酶对神经元 L 型钙通道的调节

• 批准号: 8197228
• 负责人: MARK L DELL'ACQUA
• 金额: $ 33.95万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8197228
• 关键词: A kinase anchoring protein; Address; Adenylate Cyclase; Adrenergic Receptor; Affinity; Aging; Alzheimer' s Disease; Binding; Biochemical; Biological; CREB1 gene; Calcineurin; Calcium Channel; Calcium ion; Calcium/calmodulin-dependent protein kinase; Calmodulin; Cardiac Myocytes; Cell Nucleus; Cell Survival; Cell membrane; Cells; Complex; Coupling; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Dendrites; Dendritic Spines; Development; Distal; Down Syndrome; Enzymes; Equilibrium; Event; Excitatory Synapse; Feedback; Gene Expression; Genetic Transcription; Heart; Hippocampus (Brain); Impaired cognition; L-Type Calcium Channels; L-type calcium channel alpha(1C); Lead; Learning; Leucine Zippers; Mediating; Memory; Mental Retardation; Modeling; Molecular; Muscle Cells; Myocardial Contraction; Nerve Degeneration; Neuronal Plasticity; Neurons; Nuclear; Pathway interactions; Phosphorylation; Phosphotransferases; Physiological; Play; Positioning Attribute; Production; Protein Kinase; Protein phosphatase; Proteins; Recruitment Activity; Regulation; Role; Scaffolding Protein; Signal Transduction; Site; Surface; Synaptic plasticity; System; Testing; calcineurin phosphatase; computerized data processing; molecular assembly/self assembly; neuronal survival; novel; novel therapeutics; postsynaptic; protein complex; reconstitution; response; scaffold; transcription factor; voltage

Elucidating mechanisms regulating neuronal survival and plasticity is relevant for understanding normal learning and memory as well as cognitive impairments in mental retardation, aging and Alzheimer¿s. Influx of calcium ions (Ca2+) through L-type voltage-gated calcium channels (LTCCs) can influence long-term changes in synaptic plasticity and neuronal survival by turning on and off gene transcription in the nucleus. While it is known that signaling very near the site of Ca2+ influx is required for regulation of both LTCC activity and gene expression, molecular mechanisms that organize channel proximal signals and transduce them to the nucleus are largely unknown. One important pathway by which LTCC activity in neurons is regulated involves b-adrenergic receptor-mediated stimulation of cAMP production by adenylyl cyclase and activation of the kinase PKA. Previous studies in the heart suggest that efficient regulation of LTCC activity by PKA requires phosphorylation of the channel protein and localization of PKA near the channel through binding to A-kinase-anchoring proteins (AKAP). However, little is known about the roles of AKAPs or the opposing actions of protein phosphatases in neuronal LTCC regulation. In postsynaptic neurons one AKAP that may play a key role in regulating LTCC phosphorylation and signaling to transcription factors in the nucleus is AKAP79/150. Our overall hypothesis is that AKAP79/150 targets PKA and CaN to LTCCs to bi-directionally regulate channel activity and signaling to the nucleus. We will test this hypothesis in the context of a model in which anchored CaN strongly opposes cAMP-PKA regulation of the channel currents to function as a Ca2+ negative feedback mechanism. In addition, we will explore a novel role for dynamic anchoring of PKA and CaN to AKAP79/150 in these plasma membrane localized Ca2+ signaling events that also control downstream activation of NFAT and CREB transcription factors. Thus, our studies will characterize a novel molecular assembly that coordinates plasma membrane LTCC Ca2+ signaling to regulate both local and distal responses that are important in neuronal plasticity. We will use biochemical, cell biological and electrophysiological approaches in HEK-293 cells and hippocampal neurons to study AKAP79/150-LTCC regulation: (Aim 1) Molecular and functional characterization of a direct interaction between AKAP79/150 and the LTCC CaV1.2 in neuronal channel regulation; (Aim 2) Role of dynamic PKA and CaN anchoring to AKAP79/150 in neuronal LTCC regulation; (Aim 3) Role of the AKAP79/150 channel-associated signaling complex in regulating neuronal LTCC excitation-transcription coupling.

阐明调节神经元存活和可塑性的机制与 了解正常的学习和记忆以及心理认知障碍 发育迟缓、衰老和阿尔茨海默病¿ s. 钙离子 (Ca2+) 通过 L 型电压门控流入 钙通道（LTCC）可以影响突触可塑性和神经元的长期变化 通过打开和关闭细胞核中的基因转录来生存，而众所周知，信号传导。 LTCC 活性和基因的调节需要非常靠近 Ca2+ 流入位点 表达、组织通道近端信号并转导它们的分子机制 LTCC 在神经元中的活动的一个重要途径目前尚不清楚。 调节涉及 b-肾上腺素能受体介导的 cAMP 产生刺激 先前在心脏中的研究表明，腺苷酸环化酶和激酶 PKA 的激活。 PKA 有效调节 LTCC 活性需要通道蛋白的磷酸化和 PKA 通过与 A 激酶锚定蛋白 (AKAP) 结合而定位在通道附近。 然而，人们对 AKAP 的作用或蛋白质的相反作用知之甚少。 神经元 LTCC 调节中的磷酸酶 在突触后神经元中，AKAP 可能发挥着重要作用。 在调节 LTCC 磷酸化和细胞核转录因子信号传导中发挥关键作用 我们的总体假设是 AKAP79/150 将 PKA 和 CaN 靶向 LTCC。 双向调节通道活动和向细胞核发出的信号 我们将对此进行测试。 锚定 CaN 强烈反对 cAMP-PKA 模型背景下的假设 通道电流的调节起到Ca2+负反馈机制的作用。 此外，我们将探索 PKA 和 CaN 动态锚定到 AKAP79/150 的新作用 这些质膜局部 Ca2+ 信号传导事件也控制下游激活 因此，我们的研究将表征一种新的分子。 协调质膜 LTCC Ca2+ 信号传导以调节局部和 对神经元可塑性很重要的远端反应我们将使用生物化学、细胞生物学。 以及 HEK-293 细胞和海马神经元的电生理学方法进行研究 AKAP79/150-LTCC 调节：（目标 1）直接的分子和功能表征 AKAP79/150 与 LTCC CaV1.2 在神经通道调节中的相互作用； 动态 PKA 和 CaN 锚定于 AKAP79/150 在神经元 LTCC 调节中的作用（目标 3） AKAP79/150 通道相关信号复合物在调节神经元 LTCC 中的作用 激发-转录耦合。