CALMODULIN DEPENDENT KINASE AND SYNAPTIC FUNCTION

一种II型钙/钙调蛋白依赖的蛋白激酶(CaM) 二)将细胞骨架蛋白磷酸化为主要底物 在神经元中高度集中，包括突触后 密度(PSD)。全酶包含两个自磷酸化， 50 KDa和60 KDa的钙调蛋白结合亚基 在发育过程中差异表达，并存在于变量中 不同脑区的比例。建议的一个目标是 项目的目的是确定每个亚单位是否自主发挥作用。 主要的50 KDa亚基是主要的突触后密度蛋白 (MPSDp)，占PSD的16%-50%。50美元的数额 PSD中的Kda/mPSDp在出生后发育期间发生变化， 感觉剥夺，以及当动物被放在浓缩的 表明CaM激酶II在环境中起着重要作用 在突触功能上。同时出现在突触上的还有 微管相关蛋白2和神经丝 蛋白质，这是细胞骨架蛋白底物的激酶。 MAP-2和NF在体内均被磷酸化，但其结合部位 特异性、磷酸化效应或生理上的相关性 参与其中的激酶尚不清楚。第二个目标是确定 CaM激酶II对这些蛋白功能的影响。另外， 我不知道该蛋白的磷酸化状态是否改变 激酶和/或其底物蛋白影响突触功能。 该项目的最终目标是确定CaM激酶 与胞浆激酶相比，PSD中的II发生改变，并且 建立一种模型来阐明CaM激酶II在突触中的作用 功能。 本提案中的工作假设是CaM激酶 PSD中的II高度磷酸化，而这种磷酸化 稳定PSD作为神经元中的结构成分。 私营部门司的稳定可能对建立和实施私营部门改革至关重要 保持突触前和突触后的突触接触 神经元。内源性MAP 2的磷酸化有望减少 MAP 2/蛋白质和MAP 2/膜相互作用可能是 对蛋白质和膜的周转很重要。磷酸化 CaM激酶II表达的神经丝蛋白可能稳定 神经丝。拟议的项目将有助于我们的 对几种神经性疾病的认识 在神经元细胞骨架和/或突触神经传递中 观察，包括阿尔茨海默病，癫痫肌萎缩症 侧索硬化症和关岛形式的帕金森氏症。

A Type II calcium/calmodulin-dependent protein kinase (CaM kinase II) that phosphorylates cytoskeletal proteins as major substrates in highly concentrated in neurons, including the postsynaptic density (PSD). The holoenzyme contains two autophosphorylating, calmodulin-binding subunits of 50 KDa and 60 KDa that are differentially expressed during development and exist in variable proportions in different brain regions. One goal of the proposed project is to determine if each subunit functions autonomously. The major 50 KDa subunit is the major postsynaptic density protein (mPSDp) that comprises 16-50% of the PSD. The amount of 50 KDa/mPSDp in the PSD is altered during post-natal development, sensory deprivation, and when animals are placed in enriched environments, suggesting that CaM kinase II plays an important role in synaptic function. Also present at the synapse are the microtubule-associated protein 2 (MAP 2) and neurofilament (NF) proteins, which are cytoskeletal protein substrates for the kinase. Both MAP 2 and NF are phosphorylated in vivo, but the site specificity, effect of phosphorylation, or physiologically relevant kinase involved are unknown. A second goal is to determine the effects of CaM kinase II on the function of these proteins. Also, i is not known whether changes in the phosphorylation state of the kinase and/or its substrate proteins affects synaptic function. The final goals of the project are to determine whether CaM kinase II in the PSD is altered compared to the cytosolic kinase, and to develop a model to elucidate the role of CaM kinase II in synaptic function. The working hypothesis in the present proposal is that CaM kinase II in the PSD is highly-phosphorylated, and that phosphorylation stabilizes the PSD as a structural component in neurons. Stabilization of the PSD may be important in the establishment and maintenance of synaptic contact between the pre- and postsynaptic neurons. Phosphorylation of endogenous MAP 2 is expected to reduce MAP 2/protein and MAP 2/membrane interactions which may be important for protein and membrane turnover. Phosphorylation of neurofilament proteins by CaM kinase II may stabilize neurofilaments. The proposed project will contribute to our understanding of several neurological disorders where alterations in the neuronal cytoskeleton and/or synaptic neurotransmission are observed, including Alzheimer's disease, epilepsy amyotrophic lateral sclerosis and the Guam form of Parkinsonism.