Muscleblind facilitates kinesin dependent RNA localization in neurons

项目总结/摘要 RNA定位和局部蛋白质合成使高度分化的有丝分裂后细胞，如神经元， 对外界干扰作出反应，及时有效地调节专门区室中的蛋白质水平， 方式正确的RNA定位和局部翻译对于学习基础的神经元功能是必要的 和记忆强直性肌营养不良1型（DM 1），影响全球1/8000，是一个例子， 这种RNA错误定位可能导致疾病进展。虽然DM 1的肌肉症状 经过深入研究，DM 1患者还存在多种使CNS衰弱的症状，如 嗜睡、快感缺乏和神经认知/行为障碍。阐明其基本机制至关重要 RNA在健康神经元中的定位，以更好地了解与疾病相关的CNS症状 涉及RNA错误定位，例如DM 1。在这个拟议的项目中，我们计划采用多方面的方法 结合了多种成像和生化技术。来自野生型小鼠的原代皮层神经元 胚胎大脑将作为我们的主要模型。Bassell实验室在研究RNA方面有着广泛的背景 他在生物学领域有着丰富的研究成果，并发表了大量关于RNA结合蛋白（RBP）的作用的文章。 运动神经元生长迟缓（FMRP）和运动神经元存活（SMN）蛋白，这些蛋白也在相关的神经系统疾病中受到影响。 疾病本项目的目标是阐明一个特定的RBP在DM 1发病机制中的作用， 肌盲（MBNL）作为mRNA从细胞体定位到突触前区室的促进剂。 我们假设，MBNL作为一个适配器之间的mRNA货物和特定的驱动蛋白马达蛋白（KIFs）。 与其他马达蛋白相比，驱动蛋白被选为该提议的焦点，因为已经确定， 驱动蛋白促进细胞货物远离索马的长距离顺行运动。另一 本项目的目标是鉴定与MBNL相互作用的特异性Kifs，以将靶mRNA转录物转运至 神经元内的正确目的地。根据货物和目的地，某些Kif或Kif组合 可能需要适当的运输。这项工作将加强我们对RNA定位的理解， 限制性商业惯例在这一进程中的作用。这项研究也将推动未来的研究，以确定各种 RNA转运颗粒的组分，不仅对于定位是必需的，而且对于颗粒形成也是必需的， 锚定和拆卸。从这个项目中获得的知识可以应用于病理条件 这是由于RNA错误定位引起的，例如DM 1。

PROJECT SUMMARY/ABSTRACT RNA localization and local protein synthesis enable highly differentiated, post-mitotic cells, such as neurons, to respond to external perturbations and adjust protein levels in specialized compartments in a timely and efficient manner. Proper RNA localization and local translation are necessary for neuronal functions that underlie learning and memory. Myotonic Dystrophy Type 1 (DM1), which affects 1 in 8000 worldwide, is an example of disease in which RNA mislocalization may contribute to disease progression. While the muscular symptoms of DM1 have been thoroughly studied, DM1 patients also present with multiple debilitating CNS symptoms, such as hypersomnia, anhedonia, and neurocognitive/behavioral disorders. It is critical to elucidate the basic mechanism of RNA localization in healthy neurons to better understand the CNS symptoms associated with a disease involving RNA mislocalization, such as DM1. In this proposed project, we plan to utilize a multi-faceted approach that combines multiple imaging and biochemical techniques. Primary cortical neurons from wild type mouse embryonic brains will serve as our principal model. The Bassell Lab has extensive background in studying RNA biology and has published extensively on the roles of the RNA-Binding Proteins (RBPs) Fragile X Mental Retardation (FMRP) and Survival of Motor Neuron (SMN) proteins which are also affected in related neurological diseases. The goal of this project is to elucidate the role that a specific RBP implicated in DM1 pathogenesis, Muscleblind (MBNL), has as a facilitator of mRNA localization from the cell body to pre-synaptic compartments. We hypothesize that MBNL acts an adaptor between its mRNA cargo and specific kinesin motor proteins (Kifs). Kinesin was chosen over other motor proteins as the focus of this proposal because it is well-established that kinesins facilitate the long distance anterograde movement of the cellular cargo away from the soma. Another goal of this project is to identify the specific Kifs that interact with MBNL to transport target mRNA transcripts to proper destinations within neurons. Depending on the cargo and destination, certain Kifs or combinations of Kifs might necessary for proper transportation. This work will strengthen our understanding of RNA localization and the role that RBPs play in this process. This research will also motivate future studies to identify various components of RNA transport granules, necessary not only for localization, but also granule formation, anchoring, and disassembly. The knowledge gained from this project could be applied to pathological conditions that arise due to RNA mislocalization, such as DM1.