Delphilin:: a novel PDZ and formin homology domain-containing protein that synaptically colocalizes and interacts with glutamate receptor δ2 subunit
Delphilin:: a novel PDZ and formin homology domain-containing protein that synaptically colocalizes and interacts with glutamate receptor δ2 subunit
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DOI：
10.1523/jneurosci.22-03-00803.2002
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发表时间：
2002-02-01
影响因子：
5.3
通讯作者：
Kawamoto, S
中科院分区：
文献类型：
--
作者：
Miyagi, Y;Yamashita, T;Kawamoto, S
谷氨酸受体δ 2（GluRdelta 2）亚基选择性地在小脑浦肯野细胞中表达，并且在小脑长期抑郁、运动学习、运动协调和突触发育中起重要作用。我们发现了一种新的GluRdelta 2相互作用蛋白，命名为Delphilin，它包含一个单一的PDZ结构域和一个同源（FH）结构域FH 1和FH 2加上卷曲螺旋结构。据我们所知，这是第一个报道的蛋白质，含有PDZ和FH结构域。酵母双杂交和表面等离子体共振（SPR）分析表明Delphilin通过其PDZ结构域与GluRdelta 2 C末端相互作用。这也得到了在哺乳动物细胞中使用异源表达系统的免疫共沉淀实验的支持。酵母细胞和SPR分析也表明，FH 1脯氨酸丰富的区域Delphilin相互作用的可能性，与profilin，肌动蛋白结合蛋白，并与神经元Src蛋白酪氨酸激酶的Src同源3域。原位杂交结果显示Delphilin mRNA在浦肯野细胞中表达最高。Delphilin多肽在小脑的突触体膜部分中高度富集，并与GluRdelta 2亚基共免疫沉淀。包埋后的免疫金技术表明，Delphilin是选择性地定位在突触后连接的网站的平行纤维浦肯野细胞突触和共定位与GluRdelta 2。因此，Delphilin是平行纤维-浦肯野细胞突触处的突触后支架蛋白，在那里它可用于将GluRdelta 2与肌动蛋白细胞骨架和各种信号分子连接。
The glutamate receptor delta2 (GluRdelta2) subunit is selectively expressed in cerebellar Purkinje cells and plays an important role in cerebellar long-term depression, motor learning, motor coordination, and synapse development. We identified a novel GluRdelta2-interacting protein, named Delphilin, that contains a single PDZ domain and formin homology (FH) domains FH1 and FH2 plus coiled-coil structure. As far as we know, this is the first reported protein that contains both PDZ and FH domains. Yeast two-hybrid and surface plasmon resonance (SPR) analyses indicated that Delphilin interacts with the GluRdelta2 C terminus via its PDZ domain. This was also supported by coimmunoprecipitation experiments using a heterologous expression system in mammalian cells. Yeast cell and SPR analyses also demonstrated the possibility that the FH1 proline-rich region of Delphilin interacts with profilin, an actin-binding protein, and with the Src homology 3 domain of neuronal Src protein tyrosine kinase. In situ hybridization demonstrated the highest expression of Delphilin mRNA in Purkinje cells. Delphilin polypeptide was highly enriched in the synaptosomal membrane fraction of the cerebellum and coimmunoprecipitated with the GluRdelta2 subunit. The post-embedding immunogold technique demonstrated that Delphilin is selectively localized at the postsynaptic junction site of the parallel fiber-Purkinje cell synapse and colocalized with GluRdelta2. Thus, Delphilin is a postsynaptic scaffolding protein at the parallel fiber-Purkinje cell synapse, where it may serve to link GluRdelta2 with actin cytoskeleton and various signaling molecules.