Fam Sami R, Paquet Maryse, Castleberry Amanda M, Oller Heide, Lee C Justin, Traynelis Stephen F, Smith Yoland, Yun C Chris, Hall Randy A
Department of Pharmacology, Yerkes National Primate Research Center, and Division of Digestive Disease, Emory University School of Medicine, Atlanta, GA 30322, USA.
Proc Natl Acad Sci U S A. 2005 May 31;102(22):8042-7. doi: 10.1073/pnas.0408818102. Epub 2005 May 18.
P2Y(1) purinergic receptors (P2Y(1)Rs) mediate rises in intracellular Ca(2+) in response to ATP, but the duration and characteristics of this Ca(2+) response are known to vary markedly in distinct cell types. We screened the P2Y(1)R carboxyl terminus against a recently created proteomic array of PDZ (PSD-95/Drosophila Discs large/ZO-1 homology) domains and identified a previously unrecognized, specific interaction with the second PDZ domain of the scaffold NHERF-2 (Na(+)/H(+) exchanger regulatory factor type 2). Furthermore, we found that P2Y(1)R and NHERF-2 associate in cells, allowing NHERF-2-mediated tethering of P2Y(1)R to key downstream effectors such as phospholipase Cbeta. Finally, we found that coexpression of P2Y(1)R with NHERF-2 in glial cells prolongs P2Y(1)R-mediated Ca(2+) signaling, whereas disruption of the P2Y(1)R-NHERF-2 interaction by point mutations attenuates the duration of P2Y(1)R-mediated Ca(2+) responses. These findings reveal that NHERF-2 is a key regulator of the cellular activity of P2Y(1)R and may therefore determine cell-specific differences in P2Y(1)R-mediated signaling.
P2Y(1)嘌呤能受体（P2Y(1)Rs）介导细胞内Ca(2+)因ATP刺激而升高，但已知这种Ca(2+)反应的持续时间和特征在不同细胞类型中差异显著。我们用最近构建的PDZ（PSD-95/果蝇盘大蛋白/ZO-1同源）结构域蛋白质组阵列筛选P2Y(1)R羧基末端，鉴定出与支架蛋白NHERF-2（2型钠/氢交换调节因子）的第二个PDZ结构域存在一种先前未被认识的特异性相互作用。此外，我们发现P2Y(1)R与NHERF-2在细胞中相互结合，使NHERF-2介导P2Y(1)R与关键下游效应器如磷脂酶Cβ相连。最后，我们发现P2Y(1)R与NHERF-2在胶质细胞中共表达可延长P2Y(1)R介导的Ca(2+)信号传导，而点突变破坏P2Y(1)R-NHERF-2相互作用则会减弱P2Y(1)R介导的Ca(2+)反应的持续时间。这些发现揭示NHERF-2是P2Y(1)R细胞活性的关键调节因子，因此可能决定P2Y(1)R介导信号传导中的细胞特异性差异。
