Mechanisms of CaM Kinase II signal Transduction

描述(申请人提供)：CA2？依赖性蛋白激酶II(CaMKII)对正常突触可塑性、学习和记忆至关重要。长期目标是了解树突状CaMKII能够适当调节神经递质受体、翻译、兴奋性、细胞骨架动力学和细胞形态的机制。 十二聚体CaMKII全酶在多个位点的自动磷酸化解释动态树突 钙离子发出信号，“微调”激酶活性。我们的总体假设是，CaMKII亚细胞定位和信号转导受到与CaMKII相关蛋白(CaMKAPs)相互作用的调节。在最初的资金周期中，我们鉴定了几个实际的或可能的CaMKAP，包括NMDA型谷氨酸受体(NMDAR)NR2B亚基、致密素-180的剪接变体、α-肌动蛋白-2和SAP97。CaMKII激活/自动磷酸化以不同的方式调节这些相互作用，进而通过不同的机制相互调节CaMKII的活性。此外，我们发现CaMKII可以配位多个CaMKAP的复合体，α-肌动蛋白-2可能提供与肌动蛋白细胞骨架的联系。最令人兴奋的是，CaMKII与NR2B的结合在CaMKII增强含NR2B的NMDARs的脱敏中似乎是重要的。 持续的应用程序建议进一步使用生化、分子、 电生理、显微镜和免疫学技术。NR2B与抑制素-2和CaMKII的相互作用在NMDAR调节和CaMKII靶向中的作用将在细胞培养模型中建立，并使用消除NMDAR NR2A或NR2B亚基的新型基因敲除小鼠。在细胞培养中的研究也将为密度蛋白-180与CaMKII和α-肌动蛋白-2的剪接变体复合体确立新的作用。最后，将确定SAP97和其他CaMKAP在调节GluR1磷酸化中的作用。 突触传递的紊乱导致许多神经系统疾病，包括帕金森氏病、成瘾、抑郁、精神分裂症和癫痫，我们已经证明CaMKII在其他生物系统中是一个可行的治疗靶点。因此，这些机制研究将提高我们对CaMKII在调节突触传递中的作用的基本理解，为潜在的治疗多发性脑疾病的新策略提供洞察。

DESCRIPTION (provided by applicant): Ca2????dependent protein kinase II (CaMKII) is critical for normal synaptic plasticity, learning and memory. The long-term goal is to understand mechanisms that allow dendritic CaMKII to appropriately regulate neurotransmitter receptors, translation, excitability, cytoskeletal dynamics and cell morphology. Autophosphorylation of dodecameric CaMKII holoenzymes at multiple sites interprets dynamic dendritic calcium signals, "fine-tuning" the kinase activity. Our overall hypothesis is that CaMKII subcellular localization and signaling is modulated by interactions with CaMKII Associated Proteins (CaMKAPs). In the initial funding cycle, we identified several actual or putative CaMKAPs, including NMDA-type glutamate receptor (NMDAR) NR2B subunits, splice variants of densin-180, a-actinin-2 and SAP97. CaMKII activation/autophosphorylation differentially modulates these interactions, which in turn reciprocally regulate CaMKII activity by distinct mechanisms. In addition, we showed that CaMKII can coordinate complexes involving multiple CaMKAPs, with a-actinin-2 potentially providing a link to the actin cytoskeleton. Most excitingly, binding of CaMKII to NR2B appears to be important in a novel CaMKII-enhanced desensitization of NR2B-containing NMDARs. The continuing application proposes to further test our overall hypothesis using biochemical, molecular, electrophysiological, microscopic and immunological techniques. The roles of NR2B interaction with aactinin-2 and CaMKII in NMDAR regulation and CaMKII targeting will be established in cell culture models and using novel knockout mice that eliminate NMDAR NR2A or NR2B subunits. Studies in cell culture will also establish new roles for densin-180 splice variant complexes with CaMKII and a-actinin-2. Finally, the roles of SAP97 and other CaMKAPs in modulating GluR1 phosphorylation will be determined. Derangements of synaptic transmission contribute to many neurological diseases, including Parkinson's Disease, addiction, depression, schizophrenia and epilepsy, and we have shown that CaMKII is a viable therapeutic target in other biological systems. Consequently, these mechanistic studies will improve our fundamental understanding of the role of CaMKII in regulating synaptic transmission, providing insight into potential new strategies for treatment of multiple brain disorders.