Regulation of Axonal Transport by the JNK (c-Jun N-terminal Kinase) Pathway

JNK（c-Jun N 末端激酶）途径对轴突运输的调节

• 批准号: 8060866
• 负责人: Meng-Meng Fu
• 金额: $ 4.18万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8060866
• 关键词: Affect; Alzheimer' s Disease; Amyloid beta-Protein Precursor; Axon; Axonal Transport; Behavior; Binding; Cell Death Signaling Process; Cells; Cessation of life; Co-Immunoprecipitations; Complex; Data; Defect; Distal; Dominant-Negative Mutation; Dynein ATPase; Exhibits; Fluorescent Dyes; Injury; Integral Membrane Protein; Kinesin; LRRK2 gene; Label; Life; Link; Measures; Mediating; Microscopy; Molecular; Motor; Mutate; Nerve Degeneration; Neurodegenerative Disorders; Neuronal Injury; Neurons; Organelles; Parkinson Disease; Pathway interactions; Phosphorylation; Population; Post-Translational Protein Processing; Process; Property; Proteins; Regulation; Research; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Small Interfering RNA; Speed; Staging; Stress; Synapses; Testing; Transfection; Travel; Vesicle; anterograde transport; base; biological adaptation to stress; dynactin; insight; knock-down; mutant; neuronal cell body; phosphatase inhibitor; protein function; protein misfolding; research study; response; retrograde transport; stress-activated protein kinase 1; therapeutic target

DESCRIPTION (provided by applicant): Axonal transport in neurons is essential for the delivery of functional proteins to the synapse, for clearance of damaged or misfolded proteins, and for long-distance signaling from the distal axon to the cell body. However, regulation of axonal transport in terms cargo recognition and transport behavior (speed, direction, pausing) is poorly understood. This study proposes the idea that transport of organelles can be modulated by changes in intracellular signaling, such as activation of JNK (c-Jun N-terminal kinase), which has been implicated in stress response and neuronal death. My preliminary data from neuronal cultures shows that pharmacological inhibition of JNK inhibits vesicular transport in both directions and that activation of JNK increases the speed of retrograde transport. An excellent candidate for mediating these transport responses is JIP1 (JNK-interacting protein), which has the ability to associate with JNK, both anterograde and retrograde motor proteins, and vesicles (via transmembrane proteins). In addition, the preliminary observation that JNK activation also leads to phosphorylation of JIP1 supports the hypothesis that JNK-induced phosphorylation of JIP1 leads to changes in axonal transport by altering the interaction between JIP1 and motor proteins. To verify this hypothesis, the proposed experiments will use live-cell microscopy to characterize the effects of pharmacological manipulation of JNK signaling on the transport of specific fluorescently labeled vesicle populations. Also, siRNA knockdown experiments will be used to determine whether these JNK-induced changes are mediated by JIP1. Further, coimmunoprecipitations will more clearly elucidate the interaction between JIP1 and the retrograde motor complex, dynein/dynactin. Finally, mutant nonphosphorylatable JIP1 constructs will be used to determine whether JIP1 phosphorylation is the mechanism responsible for these JNK-induced changes in transport. These experiments will further the idea that axonal transport can be regulated at the cargo level via post-translational modification in response to signaling pathway activation. A better understanding of the connection between injury signaling and transport will provide new insight into the role of transport dysregulation in neurodegenerative diseases. PUBLIC HEALTH RELEVANCE: Neurons are specialized cells that contain long processes called axons along which electrical information travels. In order to maintain normal neuronal function, proteins and organelles must be transported at great distances along these axons to and from the cell body. This project investigates the role of an injury signaling pathway in regulating axonal transport properties, such as which cargos are transported and how fast they move, and will provide insight into understanding the role of axonal transport in neuronal injury and neurodegeneration.

描述（由申请人提供）：神经元中的轴突运输对于将功能性蛋白质递送至突触、清除受损或错误折叠的蛋白质以及从远端轴突至细胞体的长距离信号传导至关重要。然而，调节轴突运输货物识别和运输行为（速度，方向，暂停）知之甚少。这项研究提出了这样的想法，即细胞器的运输可以通过细胞内信号的变化来调节，例如JNK（c-Jun N-末端激酶）的激活，这与应激反应和神经元死亡有关。我从神经元培养的初步数据表明，药理学抑制JNK抑制囊泡运输在两个方向和JNK的激活增加逆行运输的速度。介导这些转运反应的一个很好的候选者是JIP 1（JNK相互作用蛋白），它能够与JNK、顺行和逆行马达蛋白以及囊泡（通过跨膜蛋白）结合。此外，JNK激活也导致JIP 1磷酸化的初步观察支持了JNK诱导的JIP 1磷酸化通过改变JIP 1和马达蛋白之间的相互作用而导致轴突运输变化的假设。为了验证这一假设，拟议的实验将使用活细胞显微镜来表征JNK信号传导的药理学操作对特定荧光标记的囊泡群体的运输的影响。此外，siRNA敲低实验将用于确定这些JNK诱导的变化是否由JIP 1介导。此外，免疫共沉淀将更清楚地阐明JIP 1和逆行运动复合物，动力蛋白/动力蛋白之间的相互作用。最后，突变nonphosphorylatable JIP 1构建体将被用来确定是否JIP 1磷酸化是负责这些JNK诱导的运输变化的机制。这些实验将进一步的想法，轴突运输可以调节货物水平通过翻译后修饰响应信号通路的激活。更好地理解损伤信号和转运之间的联系将为神经退行性疾病中转运失调的作用提供新的见解。 公共卫生相关性：神经元是一种特殊的细胞，包含称为轴突的长过程，电子信息沿着轴突沿着。为了维持正常的神经元功能，蛋白质和细胞器必须沿着沿着这些轴突在细胞体之间进行远距离运输。该项目研究损伤信号通路在调节轴突运输特性中的作用，例如运输哪些货物以及它们移动的速度，并将为理解轴突运输在神经元损伤和神经变性中的作用提供见解。