Single molecule analysis of serotonin transporter regulation using antagonist-conjugated quantum dots reveals restricted, p38 MAPK-dependent mobilization underlying uptake activation.
Single molecule analysis of serotonin transporter regulation using antagonist-conjugated quantum dots reveals restricted, p38 MAPK-dependent mobilization underlying uptake activation.
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DOI：
10.1523/jneurosci.0048-12.2012
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发表时间：
2012-06-27
期刊：
影响因子：
--
通讯作者：
Rosenthal SJ
中科院分区：
文献类型：
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作者：
Chang JC;Tomlinson ID;Warnement MR;Ustione A;Carneiro AM;Piston DW;Blakely RD;Rosenthal SJ
突触前5-羟色胺（5-HT）转运体（SERT）是广泛开处方的抗抑郁药物的靶点。SERT表达或调节的改变与多种神经精神疾病有关，包括焦虑、抑郁和自闭症。在这里，我们实施了一种可推广的策略，利用拮抗剂共轭量子点（Qdots）首次监测血清素能细胞表面的单个SERT蛋白。我们记录了两种由横向流动性定义的SERT蛋白池，一种表现出相对自由的扩散，另一种定位于胆固醇和GM1神经节苷脂富集的微域，表现出有限的流动性。增强SERT活性的受体连接信号通路动员转运蛋白，尽管如此，这些转运蛋白仍然局限于膜微域。转运蛋白的动员源于p38 mapk依赖性的SERT c端与近膜肌动蛋白细胞骨架的分离。我们的研究建立了配体共轭Qdots用于分析单膜蛋白行为的效用，并揭示了信号介导的SERT调控的物理基础。
The presynaptic serotonin (5-HT) transporter (SERT) is targeted by widely prescribed antidepressant medications. Altered SERT expression or regulation has been implicated in multiple neuropsychiatric disorders, including anxiety, depression and autism. Here, we implement a generalizable strategy that exploits antagonist-conjugated quantum dots (Qdots) to monitor, for the first time, single SERT proteins on the surface of serotonergic cells. We document two pools of SERT proteins defined by lateral mobility, one that exhibits relatively free diffusion, and a second, localized to cholesterol and GM1 ganglioside-enriched microdomains, that displays restricted mobility. Receptor-linked signalling pathways that enhance SERT activity mobilize transporters that, nonetheless, remain confined to membrane microdomains. Mobilization of transporters arise from a p38 MAPK-dependent untethering of the SERT C-terminus from the juxtamembrane actin cytoskeleton. Our studies establish the utility of ligand-conjugated Qdots for analysis of the behaviour of single membrane proteins and reveal a physical basis for signaling-mediated SERT regulation.