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马达来动态调节微管结构：动蛋白和 动力蛋白。有趣的是，许多典型的有丝分裂动蛋白在有丝分裂后神经元中表达。这些激动素 被认为参与了神经元中MT的重新定位，但它们的确切功能以及它们是如何被调节的 在神经元中的作用是未知的。值得注意的是，Kinesin-5的突变会导致与智力残疾相关的疾病 然而，在人类中，对于为什么会发生这种情况，缺乏机械上的理解。此前， Puthan veettil实验室发现，运动蛋白家族(Kifs)的成员在生理上受到 神经元是长期记忆存储所必需的。该实验室最近的研究发现，KIF11 (Kinesin-5)对海马神经元的兴奋性突触传递起抑制作用。RNAi- KIF11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，树突状分支增加，突触密度增加。KIF11是唯一已知的 同源四聚体激动素，在有丝分裂过程中，具有四个面向外的缓慢运动结构域，以结合极间MT， 并阻止其他动蛋白，以确保正确的纺锤体形成。KIF11是如何调节结构的尚不清楚 海马神经元的变化，以及KIF11是否在长期记忆存储中起作用。我的中央 假设KIF11介导的MT动力学调节是活性依赖的结构所必需的 树突棘和长期记忆的变化。为了测试这一点，在Aim1中，我将揭示背后的机制 KIF11如何通过检查脊柱形态的活动依赖性变化来调节结构的可塑性 双光子显微镜观察谷氨酸去势后WT、KIF11 kD和KIF11过表达神经元 (2p)成像，同时通过EB1可视化MT动态。在目标2中，我将测试损失的影响 学习记忆行为检测中KIF11在背侧CA1神经元的功能及功能获得。 这些目标的完成将为KIF11在结构上的机制和调控带来新的见解 可塑性和记忆力。此外，这些研究将极大地促进我们对有丝分裂运动蛋白的理解。 在有丝分裂后神经元中。

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.