Activity-Dependent Nucleation of Dynamic Microtubules at Presynaptic Boutons Controls Neurotransmission.
Activity-Dependent Nucleation of Dynamic Microtubules at Presynaptic Boutons Controls Neurotransmission.
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突触前布顿处动态微管的活动依赖性成核控制神经传递。
DOI：
10.1016/j.cub.2019.10.049
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Bartolini,Francesca
中科院分区：
文献类型：
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作者：
Qu,Xiaoyi;Kumar,Atul;Blockus,Heike;Waites,Clarissa;Bartolini,Francesca
微管 (MT) 成核和动力学的控制对于神经元功能至关重要。 MT 成核是否在突触前节段受到调节并影响整体突触前活动仍然未知。通过观察培养的海马神经元轴突和表达 EB3-EGFP 和 vGlut1-mCherry 的海马切片中单个兴奋性传递按钮的 MT 加端动态，我们发现动态 MT 优先从突触前按钮生长，表现出偏向性，因为它们几乎总是朝向轴突的远端，并且可以通过 神经元活动。 γ-微管蛋白表达的沉默减少了突触前 MT 成核，并且 HAUS1 或 HAUS7-augmin 亚基的耗尽增加了在 bouton 处启动的逆行彗星的百分比，表明 γ-微管蛋白和 augmin 是均匀远端定向的动态 MT 的活性依赖性去新核所需的。我们分析了一系列轴突细胞器以及突触小泡 (SV) 相对于 vGlut1+ 稳定突触前 boutons 在一个时间窗口内的动态，在此期间，在诱导神经元活动时促进 boutons 处的 MT 成核，我们发现 γ-微管蛋白依赖性突触前 MT 成核控制双向 (SV) interbouton 运输和调节诱发的 SV 胞吐作用。因此，en passantboutons 充当了依赖于活性的 de novoMT 成核的热点，它通过为神经递质释放位点之间的 SV 双向传递提供动态轨迹来控制神经传递。
Control of microtubule (MT) nucleation and dynamics is critical for neuronal function. Whether MT nucleation is regulated at presynaptic boutons and influences overall presynaptic activity remains unknown. By visualizing MT plus-end dynamics at individual excitatoryen passantboutons in axons of cultured hippocampal neurons and in hippocampal slices expressing EB3-EGFP and vGlut1-mCherry, we found that dynamic MTs preferentially grow from presynaptic boutons, show biased directionality in that they are almost always oriented toward the distal tip of the axon, and can be induced by neuronal activity. Silencing of γ-tubulin expression reduced presynaptic MT nucleation, and depletion of either HAUS1 or HAUS7-augmin subunits increased the percentage of retrograde comets initiated at boutons, indicating that γ-tubulin and augmin are required for activity-dependentde novonucleation of uniformly distally oriented dynamic MTs. We analyzed the dynamics of a wide range of axonal organelles as well as synaptic vesicles (SVs) relative to vGlut1+stable presynaptic boutons in a time window during which MT nucleation at boutons is promoted upon induction of neuronal activity, and we found that γ-tubulin-dependent presynaptic MT nucleation controls bidirectional (SV) interbouton transport and regulates evoked SV exocytosis. Hence,en passantboutons act as hotspots for activity-dependentde novoMT nucleation, which controls neurotransmission by providing dynamic tracks for bidirectional delivery of SVs between sites of neurotransmitter release.