Exploring disruption of ubiquitination as a mechanism of TRPV4 gain-of-channel function in CMT2C

项目摘要 腓骨肌萎缩症（CMT）是一种退行性周围神经疾病， 遗传性神经系统疾病目前还没有有效的治疗方法，部分原因是我们的研究不完整。 了解疾病机制。钙渗透性非选择性离子通道突变 瞬时受体电位香草酸4（TRPV 4）导致通道增益功能并引起CMT 2C型。 本研究旨在确定通道活性的改变是否源于TRPV 4的变化， 翻译修饰 我们的初步数据表明，突变型TRPV 4在泛素化方面表现出缺陷，这些缺陷与TRPV 4的表达相关。 增加渠道功能。为了进一步表征TRPV 4泛素化及其在调节TRPV 4中的作用， 功能，我们的第一个目标将确定特定的赖氨酸残基泛素化的TRPV 4 N-末端， 表征野生型和突变型TRPV 4之间的泛素化差异。在我们的第二个目标中，我们将 确定操纵野生型和突变型TRPV 4泛素化对通道活性的影响， 本地化为了测量TRPV 4泛素化对体内疾病表型的影响，我们的第三个研究小组在2010年10月的一份报告中， 目的是探索操纵通道泛素化是否可以改善神经元变性， 果蝇模型。 这些发现将显著提高我们对CMT发病机制的理解， 突变型TRPV 4通道增益功能的机制和确定TRPV 4是否可以治疗性地 针对性地这项工作不仅将为TRPV 4在神经元健康中的作用提供重要的见解， 疾病，但也将告知未来的努力，以开发治疗CMT和先进的知识的作用， 在退行性神经病变中的泛素化作用。

PROJECT SUMMARY Charcot-Marie-Tooth disease (CMT) is a degenerative peripheral nerve disorder and the most commonly inherited neurologic disease. No effective treatments are currently available due in part to our incomplete understanding of disease mechanisms. Mutations in the calcium-permeable, non-selective ion channel transient receptor potential vanilloid 4 (TRPV4) result in a gain-of-channel function and cause CMT type 2C. This study seeks to determine whether alterations of channel activity stem from changes in TRPV4 post- translational modifications. Our preliminary data demonstrate that mutant TRPV4 shows deficits in ubiquitination that correlate with increased channel function. To further characterize TRPV4 ubiquitination and its role in regulating TRPV4 function, our first aim will identify specific lysine residues ubiquitinated within the TRPV4 N-terminus and characterize differences in ubiquitination between wildtype and mutant TRPV4. In our second aim, we will determine the effects of manipulating both wildtype and mutant TRPV4 ubiquitination on channel activity and localization. In order to measure the effect of TRPV4 ubiquitination on in vivo disease phenotypes, our third aim will explore whether manipulation of channel ubiquitination can ameliorate neuronal degeneration in a Drosophila model. These findings will significantly improve our understanding of the pathogenesis of CMT by defining a mechanism of mutant TRPV4 gain-of-channel function and determining whether TRPV4 can be therapeutically targeted. This work will not only provide important insights into the role of TRPV4 in neuronal health and disease, but will also inform future efforts to develop treatments for CMT and advance knowledge of the role of ubiquitination in degenerative neuropathy more broadly.