ATM SIGNALING AND NEURODEGENERATION

一个单一的基因突变，ATM，导致隐性疾病共济失调 毛细血管扩张症（AT）。 AT是一种多系统疾病， 进行性神经变性，免疫缺陷，肿瘤易感性， 性腺萎缩和放射敏感性ATM基因的克隆 使得研究基因多效性的基本原理成为可能， 大气压 使用几种ATM特异性的多克隆和单克隆抗体 我们已经证明ATM蛋白质产物是 主要是核磷蛋白，是一种真正的蛋白激酶， 并且与几种潜在的下游效应物相关， 非受体酪氨酸激酶和DNA重组/修复蛋白。 在所有症状中，神经退行性变对患者的破坏性最大 在AT。 拟议研究的目标是确定机制 ATM的这些下游效应物通过其增强神经元存活， 建立未来干预ATM介导的 神经变性 有两个具体目标：1。分子分析 ATM诱导的神经元存活所需的信号事件。 我们将 首先解决ATM、c-abl和NF-kB的效应器之一是否起作用 使用神经元细胞系和原代细胞在神经变性中的作用 小脑培养 为了识别其他信号通路，我们将 在神经元细胞中表达ATM的显性抑制形式， 表征可能与以下相关的磷酸化事件： ATM缺陷细胞中的神经变性。 我们亦会研究 ATM在细胞周期和DNA损伤中的细胞定位 使用绿色荧光蛋白和ATM融合蛋白。 我们将 鉴定神经元细胞中ATM信号通路的新组分 使用多种方法检测ATM相关蛋白。 最后， 将研究具有已知突变的原代小鼠胚胎成纤维细胞 确定ATM与其他神经元之间的调节效应关系， 特定蛋白质 2. ATM中神经元-胶质细胞相互作用的研究 介导的神经变性和抗凋亡的保护作用 基因. 动物模型将用于测试是否进行性 神经变性表现为神经元和神经胶质细胞的缺陷。 细胞 促进细胞存活的基因产物是否能阻止疾病 发展将受到考验。

Mutations of a single gene, ATM, cause the recessive disorder ataxia telangiectasia (AT). AT is a multisystem disease characterized by progressive neurodegeneration, immunodeficiency, tumor susceptibility, gonadal atrophy, and radiosensitivity. Recent cloning of the ATM gene has made it possible to study the basics of the pleiotropic effects of ATM. Using several polyclonal and monoclonal antibodies specific for ATM protein product, we have demonstrated that the ATM protein product is predominantly a nuclear phosphoprotein, is an authentic protein kinase, and is associated with several potential downstream effectors including a non-receptor tyrosine kinase and DNA recombination/repair proteins. Among all symptoms, neurodegeneration is most devastating to patients with AT. The goal of the proposed studies is to determine the mechanism by which these downstream effectors of ATM enhance neuronal survival and to establish model systems for future intervention of ATM-mediated neurodegeneration. There are two specific aims: 1. Molecular analysis of ATM-induced signaling events required for neuronal survival. We will first address whether one of the effectors of ATM, c-abl and NF-kB, play a role in neurodegeneration using neuronal cell lines and primary cerebellar cultures. To identify additional signal pathways, we will express dominant-inhibitory forms of ATM in neuronal cells to characterize the phosphorylation events that may be linked to neurodegeneration in ATM-deficient cells. We will also study the cellular localization of ATM during the cell cycle and upon DNA damage using the green fluorescent protein and ATM fusion protein. We will identify new components of ATM signaling pathways in neuronal cells using multiple approaches to detect ATM-associated proteins. Finally, primary mouse embryonic fibroblasts with known mutations will be studied to confirm the regulator and effector relationship between ATM and other specific proteins. 2. Studies of neuron-glial cell interaction in ATM- mediated neurodegeneration and protective effects of anti-apoptotic genes. Animal models will be used to test if progressive neurodegeneration is manifested by defects in both neuronal and glial cells. Whether gene products that promote cell survival thwart disease progression will be tested.