Ligand-induced rearrangement of the dimeric metabotropic glutamate receptor 1α
Ligand-induced rearrangement of the dimeric metabotropic glutamate receptor 1α
复制标题
DOI：
10.1038/nsmb770
复制
发表时间：
2004-07-01
影响因子：
16.8
通讯作者：
Kubo, Y
中科院分区：
文献类型：
--
作者：
Tateyama, M;Abe, H;Kubo, Y
代谢性谷氨酸受体1 （mGluR1）的胞外结构域形成二聚体，配体谷氨酸诱导该结构域的结构重排。然而，对于mGluR1alpha与G蛋白相互作用至关重要的细胞质结构域的构象变化尚不清楚。本研究通过荧光共振能量转移（FRET）分析在全内反射场显微镜下荧光蛋白标记的mGluR1在配体诱导的细胞质域构象变化。配体结合后，第二环之间的亚基间FRET效率增加，而第一环之间的效率降低。亚单位内FRET变化不明显。这些结果表明配体结合不会改变每个亚基的结构，但会改变细胞质区域的二聚体分配，这可能是下游信号传导的基础。
The extracellular domain of the metabotropic glutamate receptor 1 (mGluR1) forms a dimer and the ligand, glutamate, induces a structural rearrangement in this domain. However, the conformational change in the cytoplasmic domain, which is critical for mGluR1alpha's interaction with G proteins, remains unclear. Here we investigated the ligand-induced conformational changes in the cytoplasmic domain by fluorescence resonance energy transfer ( FRET) analysis of mGluR1 labeled with fluorescent protein(s) under total internal reflection field microscopy. Upon ligand binding, the intersubunit FRET efficiency between the second loops increased, whereas that between first loops decreased. In contrast, the intrasubunit FRET did not change clearly. These results show that ligand binding does not change the structure of each subunit, but does change the dimeric allocation of the cytoplasmic regions, which may underlie downstream signaling.