The catenin/cadherin adhesion system is localized in synaptic junctions bordering transmitter release zones.
The catenin/cadherin adhesion system is localized in synaptic junctions bordering transmitter release zones.
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DOI：
10.1083/jcb.135.3.767
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发表时间：
1996-11
期刊：
影响因子：
--
通讯作者：
Takeichi M
中科院分区：
文献类型：
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作者：
Uchida N;Honjo Y;Johnson KR;Wheelock MJ;Takeichi M
在神经元间突触处连接突触前膜和突触后膜的分子机制鲜为人知。我们测试了钙粘蛋白粘附系统在小鼠和鸡脑突触中的定位。我们发现，两类钙粘蛋白相关蛋白，α-N-和β-连环蛋白，广泛分布在成年人的大脑中，共定位与突触标记，突触素。在超微结构水平上，这些蛋白定位于各种类型的突触连接，形成对称的粘附结构。这些结构与突触囊泡相关的递质释放部位接壤，尽管它们的分离在某些类型的突触中不太清楚。N-钙粘蛋白也定位在突触连接的类似部位，但在有限的脑核。在发育中的突触，连接蛋白轴承接触占主导地位的连接结构。这些发现表明，神经元间突触连接包括两个亚结构域，递质释放区和连环蛋白为基础的粘附连接。位于这些连接中的连环蛋白可能与某些钙粘蛋白分子（包括N-钙粘蛋白）相关，并且钙粘蛋白/连环蛋白复合物可能在突触连接的形成或维持中起关键作用。
Molecular mechanisms linking pre- and postsynaptic membranes at the interneuronal synapses are little known. We tested the cadherin adhesion system for its localization in synapses of mouse and chick brains. We found that two classes of cadherin-associated proteins, alpha N- and beta-catenin, are broadly distributed in adult brains, colocalizing with a synaptic marker, synaptophysin. At the ultrastructural level, these proteins were localized in synaptic junctions of various types, forming a symmetrical adhesion structure. These structures sharply bordered the transmitter release sites associated with synaptic vesicles, although their segregation was less clear in certain types of synapses. N-cadherin was also localized at a similar site of synaptic junctions but in restricted brain nuclei. In developing synapses, the catenin-bearing contacts dominated their junctional structures. These findings demonstrate that interneuronal synaptic junctions comprise two subdomains, transmitter release zone and catenin-based adherens junction. The catenins localized in these junctions are likely associated with certain cadherin molecules including N-cadherin, and the cadherin/ catenin complex may play a critical role in the formation or maintenance of synaptic junctions.