Rab GTPase phosphorylation disrupts membrane trafficking in Parkinson's Disease

神经退行性疾病的遗传证据表明神经细胞膜和蛋白质的破坏 然而，贩运途径是疾病发展的主要贡献者，潜在的生物 突触小泡(SV)运输和自噬是两个重要的机制 常与神经退行性变发展有关的神经功能调控途径 疾病2虽然以前被认为是独立的，但许多研究现在已经确定了 自噬中的SV蛋白。例如，许多Rab GTP酶，膜运输的主要调节者，具有 在SV贩运和自噬中可能扮演的角色。15-18最近的一项研究发现，多个Rab GTP酶是 LRRK2，12的底物是一种当高度活跃时可导致最常见的PD.8-12基因形式的激酶 这提示了慢性磷酸化可能导致膜转运功能障碍的机制。 帕金森病发生的途径和基础。在这项提议中，我的目标是研究慢性磷酸化是如何 LRRK2表达的RAB GTP酶可能与SV周期缺陷和PD的自噬有关。具体地说，这 Proposal将通过研究Rab10在这些途径中的功能依赖于 激活状态(AIM 1)和磷酸化状态(AIM2)。这将使用生物化学、共聚焦 野生型和突变小鼠的原代神经元的显微镜和活成像方法，以及通过 活体小鼠模型。我推测，LRRK2的磷酸化在调节使用中起着开关的作用 与自噬相比，并预测慢性磷酸化导致血管紧张素转换酶功能障碍 这些通路记录在PD中。在Aim3中，我将探索一种新的研究人类的模型系统 通过从患者的成纤维细胞中产生诱导神经元而导致的神经系统疾病。该模型系统的使用 不仅将提供一个人类系统来研究帕金森病，而且还将允许比较神经细胞膜 通过检查两个人群的样本，研究遗传改变与特发性帕金森病之间的人口贩运变化。最终， 通过拟议的实验获得的知识将扩大对Rab GTP酶的理解 并可能促进开发更有针对性的治疗帕金森病的方法。

Genetic evidence from neurodegenerative diseases suggests disruption in neuronal membrane and protein trafficking pathways is a major contributor to the development of disease however, the underlying biological mechanisms remain poorly understood.1 Synaptic vesicle (SV) trafficking and autophagy are two important pathways governing neuronal function that are often implicated in the development of neurodegenerative diseases.2 Although previously considered independent, many studies have now identified additional roles of SV proteins in autophagy.3-7 For example, many Rab GTPases, major regulators of membrane trafficking, have putative roles in both SV trafficking and autophagy.15-18 A recent study has identified multiple Rab GTPases as substrates of LRRK2,12 a kinase that when hyperactive can cause the most common genetic form of PD.8-12 This suggest a mechanism whereby chronic phosphorylation may lead to dysfunction in membrane trafficking pathways and underlie PD development. In this proposal, I aim to investigate how chronic phosphorylation of Rab GTPases by LRRK2 may contribute to defects in SV cycling and autophagy found in PD. Specifically, this proposal will investigate the role of Rab10 by examining the dependence of its function in these pathways on activation state (Aim 1) and phosphorylation state (Aim2). This will be achieved using biochemical, confocal microscopy, and live imaging approaches in primary neurons from wild type and mutant mice and also through an in vivo mouse model. I hypothesize that phosphorylation by LRRK2 acts as a switch in modulating the use of Rab10 in SV cycling versus autophagy, and predict that chronic phosphorylation results in the dysfunction of these pathways as documented in PD. In Aim3, I will explore a new model system for studying human neurological diseases by generating induced neurons from patient fibroblasts. The use of this model system will not only provide a human system to study PD, but will also allow for a comparison of neuronal membrane trafficking alterations in genetic versus idiopathic PD by examining samples from both populations. Ultimately, the knowledge gained through the proposed experiments will broaden the understanding of Rab GTPases in PD and may foster the development of more targeted approaches for treating PD.