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.

阐明调查神经元生存和可塑性的机制与 了解正常的学习和记忆以及心理的认知障碍 迟钝，衰老和阿尔茨海默氏症。通过L型电压门控钙离子（Ca2+）的涌入 钙通道（LTCC）会影响突触可塑性和神经元的长期变化 通过在细胞核中打开和关闭基因转录来生存。虽然已知信号 调节LTCC活性和基因需要很近的Ca2+影响部位 表达，组织通道代理信号并传递的分子机制 对细胞核的尚不清楚。 LTCC活性在神经元中的一个重要途径 受调节涉及B-肾上腺素受体介导的cAMP生产模拟 腺苷酸环化酶和激酶PKA的激活。以前的研究表明 通过PKA对LTCC活性的有效调节需要通道蛋白的磷酸化和 通过与A-激酶锚定蛋白（AKAP）结合，在通道附近PKA的定位。 但是，关于Akap的角色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，一个可能发挥的AKAP 将LTCC磷酸化和信号传导转化为转录因子的关键作用 是AKAP79/150。我们的总体假设是AKAP79/150针对PKA，并且可以向LTCCS进行。 双向调节核的通道活性和信号传导。我们将测试这个 在模型的背景下，锚定的模型可以强烈反对营地PKA 调节通道电流以作为CA2+负反馈机制起作用。在 此外，我们还将探索PKA的动态锚定和can akap79/150的新作用 这些质膜局部局部CA2+信号传导事件，也控制下游激活 NFAT和CREB转录因子。那就是我们的研究将表征一个新颖的分子 组装坐标质膜LTCC Ca2+信号传导以调节局部和 在神经元可塑性中很重要的远端反应。我们将使用生化，细胞生物学 HEK-293细胞和海马神经元中的电生理方法研究 AKAP79/150-LTCC调节：（ AIM 1）直接的分子和功能表征 神经元通道调节中AKAP79/150与LTCC CAV1.2之间的相互作用； （目标2） 动态PKA的作用，可以在神经元LTCC调节中锚定锚定至AKAP79/150； （目标3） AKAP79/150与通道相关信号复合物在调节神经元LTCC中的作用 兴奋 - 转录耦合。