Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States.
Elife. 2020 Feb 5;9:e52009. doi: 10.7554/eLife.52009.
Correct neuronal development requires tailored neurite outgrowth. Neurite outgrowth is driven in part by microtubule-sliding - the transport of microtubules along each other. We have recently demonstrated that a 'mitotic' kinesin-6 (Pavarotti in ) effectively inhibits microtubule-sliding and neurite outgrowth. However, mechanisms regulating Pavarotti itself in interphase cells and specifically in neurite outgrowth are unknown. Here, we use a combination of live imaging and biochemical methods to show that the inhibition of microtubule-sliding by Pavarotti is controlled by phosphorylation. We identify the Ser/Thr NDR kinase Tricornered (Trc) as a Pavarotti-dependent regulator of microtubule sliding in neurons. Further, we show that Trc-mediated phosphorylation of Pavarotti promotes its interaction with 14-3-3 proteins. Loss of 14-3-3 prevents Pavarotti from associating with microtubules. Thus, we propose a pathway by which microtubule-sliding can be up- or downregulated in neurons to control neurite outgrowth, and establish parallels between microtubule-sliding in mitosis and post-mitotic neurons.
正确的神经元发育需要量身定制的轴突生长。轴突生长部分是由微管滑动驱动的，即微管沿着彼此的运输。我们最近证明，一种“有丝分裂”驱动蛋白-6（Pavarotti）有效地抑制微管滑动和轴突生长。然而，在间期中细胞中以及在轴突生长中调节 Pavarotti 本身的机制尚不清楚。在这里，我们使用活细胞成像和生化方法的组合表明，Pavarotti 对微管滑动的抑制受磷酸化控制。我们确定 Ser/Thr NDR 激酶 Tricornered（Trc）作为神经元中微管滑动的 Pavarotti 依赖性调节剂。此外，我们表明，Trc 介导的 Pavarotti 磷酸化促进其与 14-3-3 蛋白相互作用。14-3-3 的缺失阻止 Pavarotti 与微管结合。因此，我们提出了一种途径，通过该途径可以在神经元中上调或下调微管滑动以控制轴突生长，并在有丝分裂和有丝分裂后神经元中的微管滑动之间建立平行关系。
