Mechanisms of CaM Kinase II Signal Transduction

CaM 激酶 II 信号转导机制

• 批准号: 8218054
• 负责人: ROGER J COLBRAN
• 金额: $ 44.36万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-15 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8218054
• 关键词: Actinin; Amino Acids; Behavior; Binding; Biochemical; Brain; Brain region; Ca(2+)-Calmodulin Dependent Protein Kinase; Calcineurin; Calcium Channel; Calcium/calmodulin-dependent protein kinase; Calmodulin; Cells; Complex; Corpus striatum structure; Cyclic AMP-Dependent Protein Kinases; DLG1 gene; Data; Dendritic Spines; Development; Excitatory Synapse; Frequencies; Funding; Future; Glutamates; Goals; Health; Hippocampus (Brain); Human; In Vitro; Ion Channel Protein; Knock-in Mouse; Learning; Link; Mediating; Memory; Mental disorders; Messenger RNA; Molecular; Morphology; Mutant Strains Mice; Mutation; N-Methyl-D-Aspartate Receptors; Neurodevelopmental Disorder; Neurons; Pathway interactions; Phospholipids; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Play; Process; Protein Binding; Protein Isoforms; Proteins; Publications; RNA Splicing; Regulation; Research; Role; Signal Transduction; Signaling Protein; Site; Site-Directed Mutagenesis; Slice; Structure; Subcellular Fractions; Synapses; Synaptic Transmission; Synaptic plasticity; Testing; Therapeutic; Variant; calmodulin-dependent protein kinase II; density; in vivo; nervous system disorder; novel; novel strategies; postsynaptic; postsynaptic density protein; protein complex; protein protein interaction; receptor; response; synaptic function; voltage

DESCRIPTION (provided by applicant): The activity and subcellular localization of Ca2+/calmodulin(CaM)-dependent protein kinase II (CaMKII) are regulated by Ca2+/CaM binding, autophosphorylation at Thr286 and Thr305/306, and interactions with CaMKII- associated proteins (CaMKAPs). Inhibition of CaMKII, mutation of CaMKII autophosphorylation sites, or blocking CaMKII binding to NMDA receptor (NMDAR) GluN2B (formerly NR2B) subunits disrupts normal LTP at hippocampal glutamatergic synapses. However, at other excitatory synapses CaMKII is important for LTD induction or for synaptic changes independent of kinase activity. The specific molecular processes engaged by CaMKII to induce these disparate changes of synaptic function in different physiological situations remain unclear. The overarching goal of this project is to define mechanisms of CaMKII action toward specific downstream targets that are critical for normal regulation of excitatory synaptic transmission. Our unifying hypothesis is that CaMKII actions are "micro-regulated" in discrete subcellular compartments by changing the composition of CaMKII complexes with its substrates and other proteins. Thus, the repertoire of downstream CaMKII actions in a specific cellular/physiological context will be dictated by other components of these complexes. In previous funding periods, we made excellent progress characterizing CaMKII complexes containing NMDAR subunits, 21/22 subunits of voltage-gated Ca2+ channels, densin, 1-actinin and/or SAP97, generating 20 primary research publications. Interestingly, these CaMKAPs interact with CaMKII by multiple molecular mechanisms, and also typically interact with other synaptic proteins. Our findings suggest novel mechanisms for precise modulation of CaMKII-dependent actions on key synaptic signaling proteins, as well as for regulated assembly of multi-protein complexes in postsynaptic densities (PSDs). This competing renewal application proposes the use of a combination of biochemical, molecular and electrophysiological approaches in vitro, in heterologous cells, and in neurons/brain slices to test the following specific hypotheses: Aim 1: Test the hypothesis that 2 subunits and densin differentially target CaMKII isoforms to regulate L-type voltage-gated Ca2+ channels. Aim 2: Test the hypothesis that 1-actinin activates CaMKII to regulate GluN2B- NMDARs and that phospholipids modulate this pathway. Aim 3: Test the hypothesis that CaMKII interacts with and phosphorylates specific SAP97 splice variants to regulate AMPARs. Aim 4: Test the hypothesis that CaMKII autophosphorylation is modified by CaMKAPs within PSDs, and in turn regulates relevant protein- protein interactions, allowing CaMKII to play a non-catalytic, structural role. These studies will define fundamental mechanisms of physiological control that allow CaMKII to selectively regulate targets critical to different forms of synaptic plasticity, learning and memory. PUBLIC HEALTH RELEVANCE: Normal human behaviors such as learning and memory require precise control of connections (called synapses) between nerve cells in the brain, which are dependent on the activities of many receptor and ion channel proteins. CaMKII is one of the most abundant proteins at the synapse, where it can chemically modify and regulate several different target proteins, such as receptor and ion channel proteins, to elicit different responses depending on physiological demand. By defining mechanisms that allow CaMKII to selectively modify different target proteins, the proposed studies will guide the development of novel approaches to treat many neurodevelopmental, psychiatric and neurological disorders linked to abnormal synaptic functions.

描述（由申请人提供）：Ca2+/钙调蛋白（CAM）依赖性蛋白激酶II（CAMKII）的活性和亚细胞定位受CA2+/CAM结合，THR286和THR305/306时的自磷酸化，以及与Camkii I-I-I-Is相关蛋白（摄像头）的相互作用。 CAMKII的抑制作用，CAMKII自磷酸化位点的突变，或阻止CAMKII与NMDA受体（NMDAR）Glun2b（以前的NR2B）亚基的结合在海马谷氨酸胺下突触中破坏正常LTP。但是，在其他兴奋性突触中，CaMKII对于LTD诱导或与激酶活性无关的突触变化很重要。 CAMKII参与的特定分子过程在不同的生理情况下诱导突触功能的这些不同的变化尚不清楚。该项目的总体目标是将CAMKII作用的机制定义为针对特定的下游目标，这对于正常调节兴奋性突触传播至关重要。我们统一的假设是，CAMKII的作用在离散的亚细胞隔室中被“微调”，通过更改CaMKII复合物及其底物和其他蛋白质的组成。因此，在特定的细胞/生理环境中，下游CAMKII作用的曲目将由这些复合物的其他成分决定。在以前的资金期间，我们取得了出色的进步，表征了含有NMDAR亚基的CAMKII复合物，21/22电压门控Ca2+通道的21/22亚基，Densin，1-肌动蛋白和/或SAP97，产生了20个基本研究出版物。有趣的是，这些camkap通过多种分子机制与CAMKII相互作用，并且通常与其他突触蛋白相互作用。我们的发现提出了对CAMKII依赖性作用精确调节关键突触信号蛋白的新机制，以及在突触后密度（PSD）中调节多蛋白复合物的调节组装。这种竞争性更新应用提出，在体外，异型细胞和神经元/脑切片中使用生化，分子和电生理方法的组合来测试以下特定假设：目标1：测试2个亚基和致密型camkii isoferls sypecation CAMKII ISOFERS，以调节cains+ l-y-tyage-l-y-tyage vortage vol-tyage vortage vol-type。目标2：检验1-肌动蛋白激活CaMKII以调节Glun2b-NMDAR的假设，并且磷脂调节了这一途径。 AIM 3：检验CaMKII与特定的SAP97剪接变体相互作用并磷酸化以调节AMPAR的假设。 AIM 4：检验CaMKII自磷酸化的假设是由PSD中的Camkap修饰的，进而调节相关的蛋白质蛋白质相互作用，从而使Camkii可以扮演非催化的结构作用。 这些研究将定义生理控制的基本机制，使CaMKII有选择地调节对不同形式的突触可塑性，学习和记忆至关重要的目标。 公共卫生相关性：正常的人类行为，例如学习和记忆，需要对大脑中神经细胞之间的连接（称为突触）进行精确控制，这取决于许多受体和离子通道蛋白的活性。 CAMKII是突触上最丰富的蛋白质之一，在该蛋白质中，它可以化学修饰并调节几种不同的靶蛋白，例如受体和离子通道蛋白，以根据生理需求引起不同的反应。通过定义允许CAMKII选择性修改不同靶蛋白的机制，提出的研究将指导开发新的方法，以治疗与突触功能异常相关的许多神经发育，精神病和神经系统疾病。