AKAP Regulation of Neuronal L-type Calcium Channel Signaling to the Nucleus

AKAP 对神经元 L 型钙通道向细胞核信号传导的调节

基本信息

批准号：
8530768
负责人：
MARK L DELL'ACQUA
金额：
$ 53.9万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-12-15 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8530768
关键词：
A kinase anchoring protein Acute Adrenergic Agonists Adrenergic Receptor Aging Agonist Alzheimer&apos s Disease Autistic Disorder Binding Brain Calcineurin Calcium Calcium ion Calmodulin Cell Nucleus Cells Chronic Communication Coupling Cyclic AMP Cyclic AMP-Dependent Protein Kinases Cyclic AMP-Responsive DNA-Binding Protein Data Dendrites Dendritic Spines Development Distal Down Syndrome Feedback Forskolin Funding Gene Expression Gene Targeting Genetic Transcription Glutamate Receptor Glutamates Hippocampus (Brain)Image Impaired cognition Intellectual functioning disability Knock-in Mouse L Cells L-Type Calcium Channels Lasers Late Gene Transcriptions Lead Learning Leucine Zippers Link Long-Term Potentiation Luciferases Memory Messenger RNA Molecular Molecular Profiling Monitor Mus Nerve Degeneration Neuronal Plasticity Neurons Nimodipine PIX protein Pathway interactions Phase Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Positioning Attribute Protein Binding Protein Kinase RNA Interference Rattus Receptor Activation Regulation Reporter Role Scaffolding Protein Schizophrenia Signal Transduction Site Slice Stimulus Synapses Synaptic plasticity T-Cell Activation Testing Time Timothy syndrome Transcription Factor AP-1 Transcriptional Regulation Vertebral column activating transcription factor calcineurin phosphatase cellular imaging computerized data processing delta protein extracellular mRNA Expression mutant neuronal cell body novel novel therapeutics nuclear factors of activated T-cells postsynaptic protein complex public health relevance response transcription factor voltage

项目摘要

DESCRIPTION (provided by applicant): In hippocampal neurons, somato-dendritic CaV1.2 L-type voltage-gated Ca2+ channels (LTCC) function in excitation-transcription (E-T) coupling. Depolarizing stimuli that open LTCCs activate the transcription factors cAMP-response element binding protein (CREB) and nuclear factor of activated T-cells (NFAT) through Ca2+-regulated kinase and phosphatases. Importantly, LTCC transcriptional regulation is required for long-lasting forms of excitatory synaptic plasticity that underlie learning and memory, such as late-phase long-term potentiation (L-LTP). Thus, it is crucial to understand how LTCC activity and signaling are controlled to promote efficient, specific synapse to nucleus communication. The primary question in synapse-to-nucleus signaling is how local Ca2+ signals generated in dendrites are relayed remotely to the nucleus in the soma. In the last funding period, we established the postsynaptic scaffold protein A-kinase anchoring protein (AKAP) 79/150, which binds to CaV1.2 through a modified leucine zipper (LZ) motif and anchors the cAMP-dependent protein kinase (PKA) and Ca2+-calmodulin (CaM)-activated protein phosphatase-2B (calcineurin; CaN), as an essential regulator of neuronal LTCC currents and NFAT activation. We found that AKAP-anchored PKA promoted LTCC current enhancement that was strongly opposed by a Ca2+ negative feedback loop activating AKAP-anchored CaN to favor rapid, calcium-dependent inactivation (CDI). In addition, we found that local LTCC activation of AKAP-anchored CaN was required for NFAT translocation to the nucleus and transcription in response to depolarization. However, key questions remain regarding whether AKAP79/150 regulates LTCC Ca2+ influx specifically in dendritic spines in response to glutamate receptor activation and whether postsynaptic Ca2+ signals restricted in dendrites can locally activate CaN-NFAT signaling to the nucleus. We will explore these questions using a combination of whole-cell LTCC current recordings, local glutamate uncaging, Ca2+ imaging (Aim 1), NFAT imaging (Aim 2), transcriptional analyses, and extracellular recordings of L-LTP (Aim 3). In all three aims, AKAP79/150 regulation of LTCC activity and NFAT signaling will be investigated by expressing PKA anchoring deficient (delta-PKA), CaN anchoring deficient (delta-PIX), and LZ domain (delta-LZ) AKAP79 mutants in in rat neurons or using neurons from AKAP150 delta-PIX and delta-PKA knock-in mice. Overall, this project will test a central hypothesis in synapse-to-nucleus communication that postsynaptic Ca2+ signals are locally decoded in dendrites and then efficiently relayed to the nucleus to control gene expression linked to synaptic plasticity.

描述（由申请人提供）：在海马神经元中，somato dendritic cav1.2 L型电压门控CA2+通道（LTCC）在激发转录（E-T）耦合中的功能。开放LTCCS的去极化刺激激活了通过Ca2+调节的激酶和磷酸酶激活的T细胞（NFAT）的cAMP反应元件结合蛋白（CREB）和核因子。重要的是，LTCC的转录调节是基于学习和记忆（例如晚期长期增强（L-LTP））的长期兴奋性突触可塑性形式所必需的。因此，了解如何控制LTCC活性和信号传导以促进有效的，特定的突触到核通信，这一点至关重要。突触到核信号传导的主要问题是，树突中产生的局部Ca2+信号如何远程传播到Soma中的细胞核。 In the last funding period, we established the postsynaptic scaffold protein A-kinase anchoring protein (AKAP) 79/150, which binds to CaV1.2 through a modified leucine zipper (LZ) motif and anchors the cAMP-dependent protein kinase (PKA) and Ca2+-calmodulin (CaM)-activated protein phosphatase-2B (calcineurin; CaN), as an神经元LTCC电流和NFAT激活的基本调节剂。我们发现，AKAP锚定的PKA促进了LTCC电流增强，而LTCC电流的增强与CA2+负反馈环激活AKAP锚定的反馈可以有利于快速，钙依赖性的失活（CDI）。此外，我们发现，NFAT转移到核和转录响应去极化需要局部LTCC激活AKAP锚定的罐头。但是，关于AKAP79/150是否对谷氨酸受体激活的响应以及在树突中受到限制的突触后CA2+信号的响应是否可以局部激活CAN CAN-NFAT信号向原子核中限制，而在树突状棘中特别调节LTCC Ca2+涌入是否仍然存在关键问题。我们将使用全细胞LTCC当前录音，局部谷氨酸渗透，Ca2+成像（AIM 1），NFAT成像（AIM 2），转录分析和L-LTP的细胞外记录（AIM 3）的组合（AIM 3）来探讨这些问题。在所有三个目标中，将通过表达PKA锚定缺陷（Delta-PKA）来研究AKAP79/150 LTCC活性和NFAT信号的调节，可以锚定缺陷（Delta-Pix）和LZ域（Delta-Pix），以及在RATA NEURONS中使用AKAP150和使用Akap150的lakap79突变体的LZ域（Delta-Pix）和AKAP79突变体。总体而言，该项目将检验突触到核核交流的中心假设，即突触后Ca2+信号在树突中局部解码，然后有效地转发至核，以控制与突触可塑性相关的基因表达。