CRCNS: Modeling Activation of CaMKII in Spines

CRCNS：模拟脊柱中 CaMKII 的激活

基本信息

批准号：
8454553
负责人：
MARY B KENNEDY
金额：
$ 31.17万
依托单位：
CALIFORNIA INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2015-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8454553
关键词：
Actins Adverse effects Agreement Algorithms Animals Basic Science Behavior Binding Biological Biological Assay Brain Calcineurin Calcium/calmodulin-dependent protein kinase Calmodulin Calmodulin-Binding Proteins Catalytic Domain Cell physiology Chemical Engineering Communities Complex Computational Technique Computer Simulation Cytoskeleton Cytosol Dendritic Spines Development Disease Doctor of Philosophy Drug Addiction Educational process of instructing Educational workshop Egtazic Acid Employment Enzymes Event Excision Female Fire - disasters Fostering Foundations Functional disorder Glutamate Receptor Goals Grant Hippocampus (Brain)Holoenzymes Image In Vitro Individual Intervention Kinetics Knowledge Laboratories Lead Learning Location Long-Term Depression Long-Term Potentiation Medical Membrane Memory Memory impairment Mental disorders Methods Minority Modeling Molecular Molecular Models Multiprotein Complexes N-Methyl-D-Aspartate Receptors N-Methylaspartate Names Neuraxis Neurobiology Neurons Neurosciences Output Pathway interactions Phosphotransferases Positioning Attribute Postdoctoral Fellow Postsynaptic Membrane Presynaptic Terminals Process Property Proteins Publishing Pump Reaction Regulation Regulatory Pathway Relative (related person)Research Research Personnel Rewards Role Schizophrenia Shapes Short-Term Memory Signal Pathway Signal Transduction Signaling Protein Staging Structure Students Surface Synapses Synaptic Transmission Synaptic plasticity Tail Techniques Testing Time To specify Training Vertebral column Visual Work base calmodulin-dependent protein kinase II density dimer graduate student in vivo knock-down millisecond molecular modeling mutant neural circuit photolysis postsynaptic programs protein complex research study scaffold simulation syntax undergraduate student

项目摘要

DESCRIPTION (provided by applicant): The immediate objective of this proposal is to build an accurate dynamic model of activation and autophosphorylation of the signaling protein Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) during influx of Ca2+ into the postsynaptic spine through NMDA receptors. The work will proceed in three stages. First, investigators will validate a model of activation of individual monomeric catalytic subunits by Ca2+ and CaM and refine its kinetic parameters by comparing the model to experiments. The deterministic model is implemented in Mathematica; the output of the model will be tested against bench assays of the enzymatic activity of monomeric subunits of CaMKII under a wide range of concentrations of the subunits, CaM, and Ca2+. The concentrations will mimic both in vivo and in vitro conditions. In the second stage, investigators will construct a model of activation of the dodecameric holoenzyme of CaMKII, based on the model validated in the first stage. They will model cooperative activation of subunit dimers within the holoenzyme, and three different paths of autophosphorylation of its subunits. The models will be constructed in the program MCell, which supports spatially correct stochastic models of protein interactions and enzymatic activation, within biologically realistic geometries. This model will employ a new rule-based algorithm to specify the locations and behavior of subunits in holoenzymes. It will be constructed in a well-mixed volume to enable testing by comparison to bench experiments with holoenzymes under a wide range of concentrations of subunits, CaM, and Ca2+. The comparisons will be used to optimize four new parameters in the holoenzyme model, and to choose the most accurate model for progression of autophosphorylation within the holoenzyme. In the third stage, investigators will introduce optimized models of the CaMKII holoenzyme into a larger MCell model of Ca2+ influx into spines through NMDA receptors and its removal by pumps and exchangers. Simulations in MCell with this model will be used to test hypotheses about parameters governing activation of CaMKII in spines. The intellectual merit of the proposal lies in its utility in the study of mechanisms of learning in the central nervous system. The regulatory machinery in a spine controls synaptic strength by regulating activity-dependent changes such as LTP and LTD. We know much about the regulatory enzymes in a spine and we have hypotheses about enzymatic networks that regulate the cellular processes controlling synaptic plasticity, including insertion and removal of glutamate receptors and changes in the shape of the spine actin cytoskeleton. However, at the present stage of analysis, qualitative studies with mutant animals, or over-expression and knock-down of particular enzymes are the dominant paradigm in the field and they are not adequate to bring our knowledge to the next level, which is to establish the timing of the action of each of these players, and the precise conditions and position in the regulatory network at which each one becomes important. To reach that level of understanding, we need better quantitative models and methods. CaMKII is one of the the initial enzymes activated by Ca2+ coming through NMDA receptors during induction of LTP. A well-validated quantitative model of its activation in the powerful MCell program will provide a starting point and an example for the construction of dynamic models of successive steps in spine regulatory pathways. The broader impacts include the educational goal of fostering introduction of computational techniques into cellular neurobiological research. A female postdoctoral fellow will be trained in experimental techniques to test computational models, and in the use of MCell. Undergraduate students (including minority students) will be involved in the work through summer research programs at Caltech and Salk. All models will be made available to the community for download. The models of CaMKII holoenzymes will be a first example of simulation in MCell of interactions within a cytosolic multiprotein complex. The syntax for doing this will be published, and taught in the regular workshops on MCell sponsored by NSF. The proposal has medical significance. Deficiencies in spine signaling pathways that use CaMKII are associated with working memory deficits similar to those that underlie schizophrenia and related thought disorders. A quantitative understanding of the factors governing activation of CaMKII during synaptic activity, and its role in controlling synaptic plasticity will facilitate development of clinically useful pharmacological agents that target specific aspects of synaptic dysfunction with fewer undesirable side effects.

描述（由申请人提供）：该提案的直接目的是建立一个准确的动态模型，以通过NMDA受体通过NMDA受体涌入Ca2+进入CA2+的CA2+涌入Ca2+中的Ca2+过程中Ca2+涌入Ca2+过程中的依赖性蛋白激酶II（CAMKII）。这项工作将在三个阶段进行。首先，研究人员将通过CA2+和CAM验证单个单体催化亚基的激活模型，并通过将模型与实验进行比较来完善其动力学参数。确定性模型在Mathematica中实现；该模型的输出将根据camkii单体亚基的酶促活性的基准测定，在广泛浓度的亚基，CAM和Ca2+下进行测试。浓度将模拟体内和体外条件。在第二阶段，研究人员将基于在第一阶段验证的模型，构建CAMKII的十二聚体全酶的激活模型。他们将模拟全酶内亚基二聚体的合作激活，以及其亚基的自磷酸化的三个不同途径。这些模型将在程序MCELL中构建，该程序在生物学上逼真的几何形状中支持蛋白质相互作用和酶促激活的空间随机模型。该模型将采用一种新的基于规则的算法来指定全酶中亚基的位置和行为。它将在混合良好的体积中构建，以与在较大浓度的亚基，CAM和Ca2+的固定酶进行比较，从而实现测试。该比较将用于优化全酶模型中的四个新参数，并选择最精确的模型，用于全酶内自磷酸化的进展。在第三阶段，研究人员将通过NMDA受体将CAMKII Holoenzyme的优化模型引入更大的Ca2+流入模型中，并通过泵和交换器去除。 MCELL中使用此模型的模拟将用于测试有关棘中CaMKII激活的参数的假设。该提案的智力优点在于其在中枢神经系统中学习机制的研究。脊柱中的调节机制通过调节活动依赖性变化（例如LTP和LTD）来控制突触强度。我们对脊柱中的调节酶有很多了解，我们有关于调节控制突触可塑性的细胞过程的酶网络的假设，包括插入和去除谷氨酸受体以及脊柱肌动蛋白细胞骨骼的形状变化。然而，在目前的分析阶段，与突变动物的定性研究，或特定酶的过表达和击倒是该领域的主要范式，它们不足以使我们的知识成为一个新的水平，即确定每个参与者的作用的时间，以及每个人的精确条件和位置，在每个层面上都很重要。为了达到这种理解水平，我们需要更好的定量模型和方法。 CAMKII是在LTP诱导过程中通过NMDA受体激活的初始酶之一。在功能强大的MCELL程序中，其激活的验证定量模型将为脊柱调节途径连续步骤的动态模型构建提供一个起点和示例。更广泛的影响包括将计算技术引入细胞神经生物学研究的教育目标。女性博士后研究员将接受实验技术的培训，以测试计算模型，并使用McEll的使用。本科生（包括少数学生）将通过加州理工学院和Salk的夏季研究计划参与工作。所有型号都将提供给社区以供下载。 CAMKII Holoenzymes的模型将是胞质多蛋白复合物中相互作用的模拟的第一个示例。这样做的语法将出版，并在NSF赞助的McEll的常规讲习班中进行教授。该提案具有医学意义。使用CAMKII的脊柱信号通路的缺陷与与精神分裂症和相关思想障碍相似的工作记忆缺陷相关。对caMKII在突触活动过程中激活的因素的定量理解及其在控制突触可塑性中的作用将有助于开发临床上有用的药理学药物，这些药理学剂的靶向突触功能障碍的特定方面，较少的不良副作用。