Acetylcholinesterase mobility and stability at the neuromuscular junction of living mice.
Acetylcholinesterase mobility and stability at the neuromuscular junction of living mice.
复制标题
活体小鼠神经肌肉接头处乙酰胆碱酯酶的流动性和稳定性。
DOI：
10.1091/mbc.e07-02-0093
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发表时间：
2007
影响因子：
3.3
通讯作者：
Akaaboune,Mohammed
中科院分区：
文献类型：
--
作者：
Martinez-PenayValenzuela,Isabel;Akaaboune,Mohammed
乙酰胆碱酯酶（AChE）是一种在胆碱能突触的突触间隙终止乙酰胆碱神经递质功能的酶。然而，乙酰胆碱酯酶的数量和密度维持在突触间隙的机制知之甚少。在这项工作中，我们使用荧光恢复后的光漂白，光解结合，和定量荧光成像研究的表面流动性和稳定性的乙酰胆碱酯酶在成年神经支配的神经肌肉接头的活小鼠。在野生型突触，我们发现，非突触（突触周和突触外）乙酰胆碱酯酶是移动的，并逐渐招募到突触部位，大多数被困的乙酰胆碱酯酶来自连接周围池。选择性标记的一个子集的突触内的突触乙酰胆碱酯酶通过使用顺序的解结合和重新标记不同颜色的链霉亲和素，然后通过延时成像显示，突触乙酰胆碱酯酶几乎是不动的。在缺乏α-dystrobrevin（肌营养不良蛋白糖蛋白复合物的一种成分）的小鼠的神经肌肉接头处，我们发现突触AChE的密度和分布发生了深刻的改变，AChE的丢失率显著增加。这些结果表明，非突触AChE是移动的，而突触AChE是更稳定的，和α-dystrobrevin是重要的控制在神经肌肉突触的AChE的密度和稳定性。
Acetylcholinesterase (AChE) is an enzyme that terminates acetylcholine neurotransmitter function at the synaptic cleft of cholinergic synapses. However, the mechanism by which AChE number and density are maintained at the synaptic cleft is poorly understood. In this work, we used fluorescence recovery after photobleaching, photo-unbinding, and quantitative fluorescence imaging to investigate the surface mobility and stability of AChE at the adult innervated neuromuscular junction of living mice. In wild-type synapses, we found that nonsynaptic (perisynaptic and extrasynaptic) AChEs are mobile and gradually recruited into synaptic sites and that most of the trapped AChEs come from the perijunctional pool. Selective labeling of a subset of synaptic AChEs within the synapse by using sequential unbinding and relabeling with different colors of streptavidin followed by time-lapse imaging showed that synaptic AChEs are nearly immobile. At neuromuscular junctions of mice deficient in α-dystrobrevin, a component of the dystrophin glycoprotein complex, we found that the density and distribution of synaptic AChEs are profoundly altered and that the loss rate of AChE significantly increased. These results demonstrate that nonsynaptic AChEs are mobile, whereas synaptic AChEs are more stable, and that α-dystrobrevin is important for controlling the density and stability of AChEs at neuromuscular synapses.