The Active Zone T-Bar—A Plasticity Module?
The Active Zone T-Bar—A Plasticity Module?
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DOI：
10.3109/01677063.2010.489626
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发表时间：
2010-08
影响因子：
1.9
通讯作者：
C. Wichmann;S. Sigrist
中科院分区：
文献类型：
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作者：
C. Wichmann;S. Sigrist
摘要突触活性区是钙离子触发的突触囊泡融合的场所，通常与富含蛋白质、电子致密的细胞基质有关。活性区的分子组成和功能作用，特别是在囊泡胞外和胞吞作用的背景下，正在进行深入的研究。就其本身而言，果蝇突触，显示所谓的T-酒吧作为电子致密的专业化，应该是一个非常合适的模型系统，因为它们允许有效的遗传学与超微结构和电生理分析相结合。然而，它需要布赫纳实验室的生物化学方法，通过鉴定CAST/ERC家族成员Bruchpilot作为第一个T-bar驻留蛋白来“分子”访问T-bar。遗传消除Bruchpilot表明，该蛋白质是必不可少的T-酒吧的形成，钙通道集群，因此适当的囊泡融合和模式化的突触可塑性。最近，Bruchpilot被证明可以直接塑造T型杆，可能是通过采用细长的构象。此外，描述了控制Bruchpilot用于T形杆组装的可用性的第一机制。本文综述了T型杆的结构和功能，提出了T型杆是真正的“可塑性模块”的假设。
Abstract The synaptic active zone, the site where Ca2+-triggered fusion of synaptic vesicles takes place, is commonly associated with protein-rich, electron-dense cytomatrices. The molecular composition and functional role of active zones, especially in the context of vesicular exo- and endocytosis, are under intense investigation. Per se, Drosophila synapses, which display so-called T-bars as electron-dense specializations, should be a highly suitable model system, as they allow for a combination of efficient genetics with ultrastructural and electrophysiological analyses. However, it needed a biochemical approach of the Buchner laboratory to “molecularly” access the T-bar by identification of the CAST/ERC-family member Bruchpilot as the first T-bar–residing protein. Genetic elimination of Bruchpilot revealed that the protein is essential for T-bar formation, calcium channel clustering, and hence proper vesicle fusion and patterned synaptic plasticity. Recently, Bruchpilot was shown to directly shape the T-bar, likely by adopting an elongated conformation. Moreover, first mechanisms that control the availability of Bruchpilot for T-bar assembly were described. This review seeks to summarize the information on T-bar structure, as well as on functional aspects, formulating the hypothesis that T-bars are genuine “plasticity modules.”