Selective interactions between helix VIII of the human μ-opioid receptors and the C terminus of periplakin disrupt G protein activation
Selective interactions between helix VIII of the human μ-opioid receptors and the C terminus of periplakin disrupt G protein activation
复制标题
DOI：
10.1074/jbc.m305866200
复制
发表时间：
2003-08-29
影响因子：
4.8
通讯作者：
Milligan, G
中科院分区：
文献类型：
--
作者：
Feng, GJ;Kellett, E;Milligan, G
分析人Mu-阿片受体的MOP-1和MOP-1A型变异体的C末端尾部与人脑cDNA文库中的蛋白质之间的相互作用，鉴定了肌动蛋白和中间丝结合蛋白Periplakin。这种相互作用的图谱表明，所预测的受体的第四细胞内环/螺旋VIII与周斑蛋白的C末端杆状和连接区相互作用。Periplakin在人和大鼠的中枢神经系统中都有广泛的表达，并与Mu-阿片(MOP)受体呈重叠但不完全相同的分布。在HEK293细胞中，周斑蛋白与MOP-1或MOP-1-EYFP融合载体共表达并不干扰激动剂介导的受体内化。当与MOP-1-G(I1)α融合蛋白共表达时，Periplakin显著降低激动剂刺激S-35标记的鸟苷5‘-3-O-(硫代)三磷酸([S-35]GTP-GammaS)与受体相关G蛋白结合的能力。相反，Periplakin不干扰[S-35]GTP GammaS与α(2A)-肾上腺素受体-G(I1)α融合蛋白或β(2)-肾上腺素受体-G(S)α融合蛋白结合的激动剂刺激，表明其功能的选择性。这是第一个阿片受体相互作用蛋白的例子，它的功能是扰乱激动剂介导的G蛋白激活。
Analysis of interactions between the C-terminal tail of the MOP-1 and MOP-1A variants of the human mu-opioid receptor with proteins derived from a human brain cDNA library resulted in identification of the actin and intermediate filament-binding protein periplakin. Mapping of this interaction indicated that the predicted fourth intracellular loop/helix VIII of the receptor interacts with the C-terminal rod and linker region of periplakin. Periplakin is widely expressed in the central nervous system of both man and rat and demonstrated an overlapping but not identical distribution with mu-opioid (MOP) receptors. Co-expression of periplakin with MOP-1 or a MOP-1-eYFP fusion construct in HEK293 cells did not interfere with agonist-mediated internalization of the receptor. When co-expressed with a MOP-1-G(i1)alpha fusion protein periplakin significantly reduced the capacity of the agonist to stimulate binding of S-35-labeled guanosine 5'-3-O-(thio)triphosphate ([S-35]GTPgammaS) to the receptor-associated G protein. By contrast, periplakin did not interfere with agonist-stimulation of [S-35]GTPgammaS binding to either an alpha(2A)-adrenoreceptor-G(i1)alpha fusion protein or a beta(2)-adrenoreceptor-G(s)alpha fusion protein, indicating its selectivity of function. This represents the first example of an opioid receptor-interacting protein that functions to disrupt agonist-mediated G protein activation.