Molecular computation by the CaMKII holoenzyme

CaMKII 全酶的分子计算

• 批准号: 10535139
• 负责人: Carolyn Nicole Brown
• 金额: $ 3.62万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10535139
• 关键词: Address; Affinity; Avidity; Binding; Biochemical; Biochemistry; Biophysics; Calmodulin; Cells; Cognition; Cognitive; Complex; Data; Development; Excitatory Synapse; Fluorescence; Frequencies; Geometry; Hippocampus (Brain); Holoenzymes; Impairment; In Vitro; Individual; Learning; Long-Term Potentiation; Mediating; Mediator of activation protein; Memory; Mental Depression; Modeling; Molecular; Molecular Computations; Mutate; N-Methyl-D-Aspartate Receptors; Negative Staining; Neurodegenerative Disorders; Neurons; Phosphotransferases; Positioning Attribute; Process; Proteins; Reaction; Regulation; Role; Signal Transduction; Spectrum Analysis; Stimulus; Structure; Synapses; Synaptic plasticity; Variant; calmodulin-dependent protein kinase II; dimer; experimental study; insight; monomer; mutant; nervous system disorder; neuropsychiatric disorder; response; spatiotemporal; stoichiometry; three dimensional structure; tool; training opportunity

PROJECT SUMMARY Learning, cognition, and memory require dynamic remodeling of hippocampal synapses, which in turn requires Ca2+/calmodulin-dependent kinase II (CaMKII). CaMKII mediates two opposing modes of synaptic plasticity, long term potentiation (LTP) and depression (LTD), that are induced by distinct Ca2+ stimuli. Both low and high Ca2+ induce CaMKII autophosphorylation (p) at T286, that is required for both LTP and LTD. Additionally, LTP requires CaMKII binding to the NMDA receptor subunit, GluN2B, during high [Ca2+] while LTD requires CaMKII autophosphorylation at T305/306 during low [Ca2+]. Further, these three mechanisms can undergo complex cross-regulation which requires the CaMKII 12-meric holoenzyme. Interestingly, pT286 positively regulates both GluN2B binding and pT305/306 while GluN2B binding and pT305/306 are mutually exclusive. It is unknown how these reactions and interactions are spatiotemporally encoded within holoenzymes and thus how LTP versus LTD signal computation is accomplished by CaMKII. For example, it has been shown that pT286 must occur between two neighboring kinase domains in the holoenzyme. It is still unclear what determines a functional kinase domain neighbor. Moreover, in vitro binding studies have shown that CaMKII holoenzymes are required for binding to GluN2B, suggesting that this interaction may require multiple subunits. Still, it is unknown what is the required stoichiometry and subunit geometry required for CaMKII-GluN2B binding. Initial results suggest that the holoenzyme rules for pT286 and GluN2B binding are fundamentally different. Therefore, this proposal will investigate my hypothesis that LTP versus LTD mechanisms are regulated by structurally distinct features within CaMKII holoenzymes. The approach will utilize several CaMKII “structural mutants” that have disrupted holoenzyme structure (hexamers, dimers, and monomers). These mutants will be used as tools to define the spatiotemporal dynamics of autophosphorylation within holoenzymes and the subunit stoichiometry and geometry required for GluN2B binding. The results of this proposal will provide insight into how molecular signal computation underlying the LTP versus LTD decision is encoded within CaMKII holoenzymes.

项目摘要 学习，认知和记忆需要动态重塑海马突触，而这又需要 Ca2+/钙调蛋白依赖性激酶II（CAMKII）。 camkii培养了两种相反的突触可塑性模式，长长 由不同的Ca2+刺激诱导的术语定期（LTP）和抑郁症（LTD）。低Ca2+ 在T286处诱导CAMKII自磷酸化（P），这是LTP和LTD所必需的。另外，LTP需要 在高[Ca2+]期间，CAMKII与NMDA接收器亚基Glun2b结合，而LTD需要CAMKII 在低[Ca2+]期间，在T305/306处的自磷酸化。此外，这三种机制可能会经历复杂 需要CAMKII 12兆全酶的交叉调节。有趣的是，PT286对两者进行了积极调节 Glun2b结合和PT305/306，而Glun2b结合和PT305/306则相互排斥。这是未知的 这些反应和相互作用在全酶内进行了空间编码，因此LTP与 LTD信号计算由CAMKII完成。例如，已经证明必须发生PT286 在全酶中的两个相邻激酶结构域之间。仍然不清楚是什么决定功能 激酶域邻居。此外，体外结合研究表明需要CAMKII全酶 要与Glun2b结合，这表明这种相互作用可能需要多个亚基。尽管如此，尚不清楚什么是 CAMKII-GLUN2B结合所需的化学计量和亚基几何形状。最初的结果表明 PT286和GLUN2B结合的全酶规则根本不同。因此，该提议将 调查我的假设，即有限公司与有限公司机制受结构上不同特征的调节 CAMKII全酶。该方法将利用几种已残疾的CAMKII“结构突变体” 全酶结构（六聚体，二聚体和单体）。这些突变体将用作定义的工具 全酶内部自磷酸化的时空动力学和亚基化学计量学和 Glun2b结合所需的几何形状。该提案的结果将提供有关分子信号的洞察力 LTP与LTD决策基础的计算在CaMKII Holoenzymes中编码。