液-液相分離によるニューロンの無中心体性微小管核形成

我们以前的研究强调了局部放大微管生成途径在分化神经元中的关键作用。微管的产生也响应于突触活动和神经元损伤而被放大，在神经保护和再生中起作用。这就提出了一个问题，即这种扩增的分子机制是什么。在这个项目中，我们寻找一个新的非典型的过程中的微管产生的神经元，我已经筛选通过未研究的蛋白质的重要乔木的发展，通过驱动有丝分裂后微管成核。微管成核活性的实时成像（体内EB1成像），确定该过程所需的新因子。通过操纵这个因素，我表明，果蝇c4da感觉神经元表现出显着减少微管成核在树突尖端，与顺行微管数量的显着修改。这种微管成核的减少在整个微管心轴上是明显的，但优先在枝晶尖端减少。c4da神经元生长的实时成像显示，c4da神经元表现出减少的乔木延伸率，减少分支频率，导致发育不良的树突乔木。我进一步研究了这种蛋白在体外的活性，发现它上调微管成核活性。

Our previous studies emphasize a critical role for local amplification of microtubule generation pathways in differentiating neurons. Microtubule generation is also amplified in response to synaptic activity, and to neuron injury, where it plays a role in neuroprotection and regeneration. This raises the question of what molecular mechanisms underlie this amplification. In this project we looked for a new non-canonical process of microtubule generation in neurons; I have screened through unstudied proteins important for arbor development that act by driving postmitotic microtubule nucleation. Live imaging of microtubule nucleation activity (in vivo EB1 imaging), identifying a new factor required for this process. By manipulation of this factor I show that Drosophila c4da sensory neurons exhibit a dramatic reduction in microtubule nucleation at dendrite tips, with a significant modification in anterograde microtubule numbers. This reduction in microtubule nucleation is apparent across the entire microtubule arbor but is preferentially reduced at the dendrite tips. Live imaging of c4da neuron growth reveal that c4da neurons exhibit reduced arbor extension rate, and reduced branching frequency, leading to a stunted dendritic arbor. I have further investigated the activity of this protein in vitro, finding that it upregulates microtubule nucleation activity.