Novel role of mitotic kinesin KIF11 in structural plasticity and memory

项目摘要 有丝分裂细胞通过使用微管（MT）马达：驱动蛋白和微管蛋白， 动力蛋白有趣的是，许多典型的有丝分裂驱动蛋白在有丝分裂后的神经元中表达。这些驱动蛋白 被认为参与重新定位神经元中的MT，但它们的精确功能以及它们是如何被调节的， 在神经元中是未知的。值得注意的是，驱动蛋白-5的突变导致与智力残疾相关的疾病 然而，在人类中，缺乏对为什么会发生这种情况的机械理解。此前 Puthanveettil实验室揭示，蛋白质的驱动蛋白家族（KIFs）的成员在生理上受到调节， 神经元，并需要长期记忆存储。实验室最近的研究发现，KIF 11 （驱动蛋白-5），作为海马神经元中兴奋性突触传递的抑制性约束。RNAi- KIF 11介导的功能丧失分析导致微小兴奋性突触后电流增加 频率增加，树突分支增加，突触密度增加。KIF 11是唯一已知的 同源四聚体驱动蛋白，具有四个在有丝分裂期间面向外以结合极间MT的慢运动域， 并对其他驱动蛋白进行制动以确保纺锤体正确形成。目前尚不清楚KIF 11如何介导结构性 海马神经元的变化，以及KIF 11是否在长期记忆储存中发挥作用。我的中枢 假设是KIF 11介导的MT动力学调节是活性依赖性结构所必需的， 树突棘和长期记忆的变化。为了验证这一点，在Aim 1中，我将揭示背后的机制。 KIF 11如何通过检查脊柱形态的活动依赖性变化来调节结构可塑性 通过双光子显微镜观察WT、KIF 11 KD和KIF 11过表达神经元中谷氨酸释放后 (2P)成像，同时通过EB 1可视化MT动态。在目标2中，我将测试损失的影响。 在学习和记忆行为测定中，背侧CA 1神经元中KIF 11的功能和功能的获得。 这些目标的完成将为KIF 11在结构性免疫反应中的机制和调控带来新的见解。 可塑性和记忆。此外，这些研究将大大推进我们对有丝分裂驱动蛋白的理解 有丝分裂后的神经元。

Project Summary Mitotic cells dynamically regulate microtubule (MT) architecture through the use of the MT motors: kinesin and dynein. Intriguingly, many of the canonical mitotic kinesins are expressed in post-mitotic neurons. These kinesins are thought to participate in repositioning MTs in neurons, yet their precise function and how they are regulated in neurons are unknown. Notably, mutations in kinesin-5 result in disorders associated with intellectual disabilities in humans, however, there is a lack of mechanistic understanding of why this occurs. Previously, the Puthanveettil lab revealed that members of the kinesin family of proteins (KIFs) are physiologically regulated in neurons and are required for long-term memory storage. Recent studies from the lab uncovered that KIF11 (Kinesin-5), acts as an inhibitory constraint on excitatory synaptic transmission in hippocampal neurons. RNAi- mediated loss-of-function analysis of KIF11 resulted in increased mini excitatory post-synaptic currents frequencies, increased dendritic branching, and increased synapse density. KIF11 is the only known homotetrameric kinesin, with four, slow motor domains that face outward to bind interpolar MTs during mitosis, and brake against other kinesins to ensure proper spindle formation. It is unknown how KIF11 mediates structural changes in hippocampal neurons, and whether KIF11 has a role in long-term memory storage. My central hypothesis is that KIF11 mediated regulation of MT dynamics is required for the activity-dependent structural changes in dendritic spines and long-term memory. To test this, in Aim1 I will uncover the mechanism behind how KIF11 regulates structural plasticity through examining activity-dependent changes in spine morphology following glutamate uncaging in WT, KIF11 KD, and KIF11 overexpression neurons by two-photon microscopy (2P) imaging while simultaneously visualizing MT dynamics via EB1. In Aim 2 I will test the effects of the loss of function and gain of function of KIF11 in dorsal CA1 neurons in learning and memory behavior assays. Completion of these aims will bring novel insights into the mechanism and regulation of KIF11 in structural plasticity and memory. Moreover, these studies will significantly advance our understanding of mitotic kinesins in post-mitotic neurons.