Microtubule dynamics in postsynaptic structure and function: role of the microtubule severing enzyme katanin

微管细胞骨架调节不同的细胞过程，包括细胞分裂、细胞粘附和细胞迁移。此外，它还参与细胞的结构和功能，并作为分子马达及其货物运输的轨道。切断酶如spastin、katanin、fidgetin等切断微管，参与调控微管动力学。关于神经元突触的传递和功能，目前尚不清楚微管切断是否以及如何在此背景下发挥作用。本研究计划旨在利用新建立的条件katanin敲除小鼠（用于出生后，神经元特异性katanin缺失）和显性阴性方法，揭示katanin介导的微管切断在神经元突触的传递，结构和功能中的作用。一个主要的目标是研究微管的动力学，它们的亚细胞定位和它们在缺乏角朊基因表达或功能的情况下瞬间进入树突棘。此外，该项目还询问这些动态过程是否会影响微管相关蛋白（MAPs）和分子马达与微管的结合。在活神经元中使用延时视频显微镜，比较突触蛋白跨基因型的转运是一个目标。影像资料应辅以分子和生化分析。最后，电生理分析应阐明katanin耗尽是否影响突触传递。如果katanin缺失改变了突触的结构和/或功能，那么应该进一步研究神经元网络可塑性和小鼠行为，以了解微管切断对网络功能和认知的潜在贡献。

The microtubule cytoskeleton regulates different cellular processes including cell division, cell adhesion and cell migration. Furthermore, it participates in the structure and function of cells and acts as a track for the transport of molecular motors and their cargoes. Severing enzymes, such as spastin, katanin and fidgetin sever microtubules and participate in the regulation of microtubule dynamics. With respect to the delivery and function of neuronal synapses, it is currently unknown whether and how microtubule severing plays a role in this context.This research proposal aims to use a newly established conditional katanin knockout mouse (for postnatal, neuron-specific katanin depletion) and dominant-negative approaches, to unravel the role of katanin-mediated microtubule severing in the delivery, structure and function of neuronal synapses. A major goal is to study the dynamics of microtubules, their subcellular localization and their transient entry into dendritic spines in the absence of katanin gene expression or function, respectively. Moreover, the project asks whether such dynamic processes affect the binding of microtubule associated proteins (MAPs) and molecular motors to microtubules. Using time-lapse video microscopy in living neurons, it is a goal to compare the transport of synaptic proteins across genotypes. Imaging data should be complemented by molecular and biochemical assays. Finally, electrophysiological analysis should clarify whether katanin depletion affects synaptic transmission. If katanin depletion alters the structure and/or function of synapses, further assays to study neuronal network plasticity and mouse behaviour should be applied to understand a potential contribution of microtubule severing for network function and cognition.