Mechanisms of CaM Kinase II signal Transduction

描述（由申请人提供）：Ca 2？依赖性蛋白激酶II（CaMK II）对于正常的突触可塑性、学习和记忆是至关重要的。长期目标是了解树突状CaMKII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CaMK II全酶在多个位点的自磷酸化解释了动态树突状细胞 钙信号，“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是通过与CaMKII相关蛋白（CaMKAPs）的相互作用来调节的。在最初的资助周期中，我们鉴定了几种实际的或推定的CaMKAP，包括NMDA型谷氨酸受体（NMDAR）NR 2B亚基、致密蛋白-180的剪接变体、α-辅肌动蛋白-2和SAP 97。CaMKII激活/自磷酸化差异调节这些相互作用，这反过来又通过不同的机制间接调节CaMKII活性。此外，我们发现CaMKII可以协调涉及多个CaMKAP的复合物，α-辅肌动蛋白-2可能提供与肌动蛋白细胞骨架的连接。最令人兴奋的是，CaMKII与NR 2B的结合似乎在含NR 2B的NMDAR的新型CaMKII增强的脱敏中是重要的。 继续申请提出使用生物化学、分子、 电生理学、显微镜和免疫学技术。NR 2B与辅肌动蛋白-2和CaMK II的相互作用在NMDAR调节和CaMK II靶向中的作用将在细胞培养模型中并使用消除NMDAR NR 2A或NR 2B亚基的新型敲除小鼠来建立。在细胞培养中的研究也将建立致密蛋白-180剪接变体与CaMKII和α-辅肌动蛋白-2复合物的新作用。最后，将确定SAP 97和其他CaMKAP在调节GluR 1磷酸化中的作用。 突触传递的紊乱导致许多神经系统疾病，包括帕金森病、成瘾、抑郁症、精神分裂症和癫痫，并且我们已经表明CaMKII是其他生物系统中可行的治疗靶点。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，为治疗多种脑部疾病提供潜在的新策略。

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.