HUMAN SPINAL CORD PROTEIN IDENTIFICATION

克利夫兰小组的研究兴趣集中在机构上 使用分子遗传学来评估神经元的生长和死亡 轴突的生长以及是什么因素导致运动神经元选择性死亡。 与大多数真核细胞不同，神经元的一个固有特征是它们的 极度不对称。例如，在人类的外周神经 系统中，单个运动神经元的长度超过一米。不对称 是分两个阶段实现的。第一种是当轴突延伸时 朝向它的目标。在稳定的突触形成后，第二阶段 轴突直径最大可达十倍的启蒙阶段。这 径向生长阶段，伴随着减数分裂，是 建立适当的传导速度，会产生巨大的 轴突体积增加和一个巨大的细胞，其中99.9%位于 轴突。我们的部分努力集中在使用分子遗传学上。 和转基因小鼠，以测试轴突是如何实现放射状生长的。 我们已经证明了神经丝，最丰富的 轴突中的结构元素，是放射状生长所必需的。我们有 现在发现了一组神经丝相关蛋白，并在 与Burlingame博士合作，现在希望使用现代蛋白质 分析方法来确定这些关联的身份 蛋白质。一旦分离出相应的基因，我们就会使用 转基因和基因阻断方法在小鼠中的应用 相应的体内特性。除此之外，基本上所有的人类 运动神经元障碍的特征是 神经丝，这一发现清楚地表明它们可能扮演着一种 在疾病发病机制中的重要作用。这一点在 最突出的运动神经元疾病，肌萎缩侧索硬化症 硬化症，或ALS，其特征是选择性运动死亡 神经元。通过生产表达突变的转基因小鼠 神经细丝，我们已经证明这种突变可以导致ALS 老鼠，我们现在正在寻找类似突变的存在 人类病人。只有1.5%的人类肌萎缩侧索硬化症的原因是已知的，这 是一种超氧化物歧化酶的点突变。按表达式 在老鼠身上的这些突变中，我们已经证明了疾病是由一种 突变蛋白的毒性性质，我们现在正在寻找什么 这一特性是什么，是一系列事件导致的 选择性运动神经元死亡。通过使用高分辨率蛋白质 分析方法，我们现在试图确定神经细丝是否 事实上，ALS连锁SOD1引起的共价损伤靶点 突变，如果是这样，以确定异常化学的性质 由这些突变蛋白介导。

The research interests of the Cleveland group focus on mechanisms of neuronal growth and death using molecular genetics to assess how axons grow and what factors provoke selective death of motor neurons. Unlike most eukaryotic cells, an intrinsic feature of neurons is their extreme asymmetry. for example, in the human peripheral nervous system, single motor neurons extend over a meter in length. Asymmetry is achieved in two phases. The first is when a neurite extends towards its target. After stable synapse formation, a second phase initiates in which the axon grows up to ten fold in diameter. This radial growth phase, concomitant with meylination and essential for establishment of proper conduction velocity, yields an enormous increase in axonal volume and a huge cell, 99.9% of which is in the axon. We have focused part of our effort on using molecular genetics and transgenic mice to test how radial growth of axons is achieved. Already we have shown that neurofilaments, the most abundant structural element in axons, are essential for radial growth. We have now identified a set of neurofilament-associated proteins and, in collaboration with Dr. Burlingame, now wish to use modern protein analysis methods to determine the identities of these associated proteins. Once the corresponding genes are isolated we will then use transgenic and gene disruption methods in mice to determine the corresponding in vivo properties. Beyond this, essentially all human motor neuron disorders are characterized by the maldistribution of neurofilaments, a finding clearly suggesting that they may play an essential role in disease pathogenesis. This is particularly true in the most prominent motor neuron disease, amyotrophic lateral sclerosis, or ALS, which is characterized by selective death of motor neurons. By producing transgenic mice expressing mutations in neurofilaments, we have proven that such mutations can cause ALS in mice and we are now searching for the presence of similar mutations in human patients. The cause of only 1.5% of human ALS is known and this is point mutations in an enzyme superoxide dismutase. By expression of these mutations in mice, we have proven that disease arises from a toxic property of the mutant proteins and we are now looking for what that property is and what is the cascade of events leading to selective motor neuron death. By using high resolution protein analysis methods, we now seek to determine whether neurofilaments are indeed targets for covalent damage arising from ALS-linked SOD1 mutations, and if so, to identify the nature of the aberrant chemistry mediated by these mutant proteins.