A New Vesicular Scaffolding Complex Mediates the G-Protein-Coupled 5-HT1A Receptor Targeting to Neuronal Dendrites
A New Vesicular Scaffolding Complex Mediates the G-Protein-Coupled 5-HT1A Receptor Targeting to Neuronal Dendrites
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DOI：
10.1523/jneurosci.6329-11.2012
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发表时间：
2012-10-10
影响因子：
5.3
通讯作者：
Darmon, Michele
中科院分区：
文献类型：
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作者：
Al Awabdh, Sana;Miserey-Lenkei, Stephanie;Darmon, Michele
尽管树突状靶向5 -羟色胺g蛋白偶联受体的分子机制对其神经元功能至关重要，但人们对其知之甚少。在这里，我们表征了一个依赖于yif1b的囊泡支架复合物介导大鼠5-HT1A受体（5-HT1AR）向树突的细胞内运输。通过结合定向诱变、GST-pull - down和表面等离子体共振，我们在5-HT1AR的c尾部发现了一个三基基基序，Yif1B以高亲和力（K-D近似为37 nM）直接结合在该基序上。此外，我们发现Yip1A、Rab6和Kif5B是5-HT1AR/Yif1B复合物的新伙伴，并表明它们在神经元中的表达对于5-HT1AR的树突靶向也至关重要。实时视频显微镜显示，5-HT1AR、Yif1B、Yip1A和Rab6在囊泡中从胞体向树突树方向运输，并表现出双向运动，维持其在5-HT1AR树突靶向中的作用。因此，我们提出了一种新的运输途径模型，其中Yif1B是在包括yif1a和Rab6的复合体中募集5-HT1AR的支架蛋白，Kif5B和动力蛋白是两个相反的分子马达，协调沿树突微管的囊泡运输。这种靶向途径为g蛋白偶联受体在神经元中的运输提供了新的见解。
Although essential for their neuronal function, the molecular mechanisms underlying the dendritic targeting of serotonin G-protein-coupled receptors are poorly understood. Here, we characterized a Yif1B-dependent vesicular scaffolding complex mediating the intracellular traffic of the rat 5-HT1A receptor (5-HT1AR) toward dendrites. By combining directed mutagenesis, GST-pull down, and surface plasmon resonance, we identified a tribasic motif in the C-tail of the 5-HT1AR on which Yif1B binds directly with high affinity (K-D approximate to 37 nM). Moreover, we identified Yip1A, Rab6, and Kif5B as new partners of the 5-HT1AR/Yif1B complex, and showed that their expression in neurons is also crucial for the dendritic targeting of the 5-HT1AR. Live videomicroscopy revealed that 5-HT1AR, Yif1B, Yip1A, and Rab6 traffic in vesicles exiting the soma toward the dendritic tree, and also exhibit bidirectional motions, sustaining their role in 5-HT1AR dendritic targeting. Hence, we propose a new trafficking pathway model in which Yif1B is the scaffold protein recruiting the 5-HT1AR in a complex including Yip1A and Rab6, with Kif5B and dynein as two opposite molecular motors coordinating the traffic of vesicles along dendritic microtubules. This targeting pathway opens new insights for G-protein-coupled receptors trafficking in neurons.