SORTING AND TRANSPORT OF SPECIFIC NEURONAL GLYCOPROTEINS

描述（来自申请人摘要）神经损伤引发长期 需要改变蛋白质合成的改变， 恢复功能。 然而，再生往往失败， 导致感觉缺陷、慢性疼痛和瘫痪。 努力 促进生长和减少感官缺陷将有助于如果我们知道 信号的身份，通知细胞索马，其轴突已被 以及这些信号如何调节转录程序， 负责成功的再生。 利用神经系统 以加州紫云英为模型，申请人发现，正伤害 在轴突损伤部位激活的信号被逆行转运到 细胞核。 当含有这些信号的轴浆被注入 在未受伤的神经元中，它诱导相同的生长和过度兴奋， 当这些细胞的轴突受伤时就会出现。 类似的 在哺乳动物神经元中，轴突切断后会出现过度兴奋， 对慢性疼痛负责。 为了识别信号， 这些变化，他们分析了轴质，发现它富含2 激酶，ERK和SAPK。 大多数ERK处于磷酸化状态（活性） 形式，申请人假设激活发生时， 损伤部位的钙激活磷酸激酶C。他们会操纵 钙水平使用离子载体，看看是否PKC受到影响。 如何ERK 是如何逆行运输的还不清楚。 他们将注射重组ERK 直接进入轴突，以监测其运输，并将使用特定的 抗体和轴浆的亚细胞分级，看看它是否发生在 与细胞器的联系。 一旦ERK到达细胞核， 磷酸化转录因子C/EBP。 这可能会增加 C/EBP对DNA的亲和力，改变转录，或调节其进入 原子核 每种可能性将使用重组野生型 和突变的C/EBP 有趣的是ERK也被神经激活 炎症，这也会引起过度兴奋。 这表明 过度兴奋是由于ERK作用于C/EBP。 他们将试图 通过显微注射抗体来干扰这一过程， 寡核苷酸和使用突变的ERK和C/EBP。 与此相反的是， 逆行运输的SAPK是组成型活性的，尽管其 损伤后活性增加，它可能通过以下途径参与生长： 研究人员有抗体和重组蛋白， 研究这种可能性，并将使用类似的战略， 受雇于ERK。

DESCRIPTION (from applicant's abstract) Nerve injury triggers long-term alterations that require changes in protein synthesis and which may result in the restoration of function. Often, however, regeneration fails, resulting in sensory deficits, chronic pain, and paralysis. Efforts to promote growth and minimize sensory defects would be facilitated if we knew the identity of the signals that inform the cell soma that its axon has been injured and how these signals regulated the transcriptional programs that are responsible for successful regeneration. Using the nervous system of Aplysia californica as a model the applicants found that positive injury signals activated at the site of axon injury are retrogradely transported to the cell nucleus. When axoplasm containing these signals is injected into non-injured neurons, it induces the same growth and hyperexcitability that appears when the axons of these cells are injured. A similar hyperexcitability occurs after axotomy in mammalian neurons and is thought to be responsible for chronic pain. To identify the signals responsible for these changes, they analyzed the axoplasm and found it to be enriched in 2 kinases, ERK and SAPK. Most of the ERK is in the phosphorylated (active) form and the applicants hypothesize that activation occurs when an influx of calcium at the lesion site activates phosphokinase C. They will manipulate calcium levels using an ionophore to see whether PKC is affected. How ERK is retrogradely transported is not known. They will inject recombinant ERK directly into the axon to monitor its transport and will use specific antibodies and subcellular fractionation of axoplasm to see if it occurs in association with an organelle. Once ERK reaches the nucleus it phosphorylates the transcription factor C/EBP. This could increase the affinity of C/EBP for DNA, alter transcription, or regulate its entry into the nucleus. Each possibility will be assessed using recombinant wild type and mutated C/EBP. Interestingly ERK is also activated by nerve inflammation, which also induces hyperexcitability. This suggests that hyperexcitability is due to ERK acting on C/EBP. They will attempt to interfere with this process by microinjecting antibodies and oligonucleotides and by using mutated ERK and C/EBP. In contrast, retrogradely transported SAPK is constitutively active, although its activity increases after injury, and it may be involved in growth through c-Jun. The investigators have antibodies and recombinant proteins to investigate this possibility and will use strategies similar to those employed for ERK.