Pharmacological and biophysical properties of the human P2X5 receptor
Pharmacological and biophysical properties of the human P2X5 receptor
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DOI：
10.1124/mol.63.6.1407
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发表时间：
2003-06-01
影响因子：
3.6
通讯作者：
North, RA
中科院分区：
文献类型：
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作者：
Bo, XN;Jiang, LH;North, RA
我们通过整合对应于外显子 10 的序列构建了全长人 P2X(5) 嘌呤受体 cDNA，该序列在之前从人体组织克隆的 cDNA 中缺失。我们通过膜片钳记录和荧光成像研究了在人胚肾293细胞中表达后的功能特性。 ATP（1-100 μM；4 μM 的半最大电流）在 -60 mV 处引发内向电流；这些在短暂（2秒）的应用中持续存在，但在较长的应用中下降。峰值电流取决于保持电位并且几乎没有整流；然而，+30 mV 时的应用过程中的脱敏和 ATP 被洗掉时的电流下降均比 -60 mV 时慢。 2', 3'-O-(4-苯甲酰基)-苯甲酰基-ATP 和 Alpha-亚甲基-ATP 模拟 ATP 的作用（半最大浓度分别为 6 和 161 μM）。电流被苏拉明、吡哆醛-5-磷酸-6-偶氮-2'、4'-二磺酸和亮蓝G抑制，半最大抑制分别为3、0.2和0.5μM； 2', 3'-O-(2',4', 6'-三硝基苯酚)-ATP (1 muM) 无效。去除二价阳离子不会显着改变 ATP 浓度-响应曲线。逆转电位测量表明，人 P2X(5) 受体可渗透钙 (P-Ca/P-Na = 1.5) 和 N-甲基-D-葡萄糖胺 (NMDG) (P-NMDG/P-Na = 0.4)；它也可渗透氯离子 (P-Cl/P-Na = 0.5)，但不能渗透葡萄糖酸离子 (P-gluc/P-Na = 0.01)。 NMDG 的渗透性随着通道的打开而迅速发展，而 P2X(7) 受体的 NMDG 渗透性在几秒钟内发展。表达人 P2X(5) 受体的细胞也响应 ATP 快速积累丙啶染料 YO-PRO-1。
We constructed a full-length human P2X(5) purinoceptor cDNA by incorporating a sequence corresponding to exon 10, which is missing in cDNAs cloned previously from human tissues. We studied the functional properties by patch-clamp recording and fluorescence imaging after expression in human embryonic kidney 293 cells. ATP (1-100 muM; half-maximal current at 4 muM) elicited inward currents at -60 mV; these persisted during brief (2 s) applications but declined during longer applications. The peak current was dependent on the holding potential and showed little rectification; however, both the desensitization during the application and the decline in the current when ATP was washed out were slower at +30 mV than at -60 mV. 2', 3'-O-(4-Benzoyl)-benzoyl-ATP and alphabeta-methylene-ATP mimicked the action of ATP (half-maximal concentrations 6 and 161 muM, respectively). The currents were inhibited by suramin, pyridoxal-5-phosphate-6-azo-2', 4'-disulfonic acid and Brilliant Blue G, with half-maximal inhibition at 3, 0.2, and 0.5 muM, respectively; 2', 3'-O-(2',4', 6'-trinitrophenol)-ATP (1 muM) was ineffective. Removing divalent cations did not significantly alter ATP concentration-response curves. Reversal potential measurements showed that the human P2X(5) receptor was permeable to calcium (P-Ca/P-Na = 1.5) and N-methyl-D-glucamine (NMDG) (P-NMDG/P-Na = 0.4); it was also permeable to chloride (P-Cl/P-Na = 0.5) but not gluconate (P-gluc/P-Na = 0.01) ions. The permeability to NMDG developed as quickly as the channel opened, in contrast to the P2X(7) receptor where the NMDG permeability develops over several seconds. Cells expressing human P2X(5) receptors also rapidly accumulated the propidium dye YO-PRO-1 in response to ATP.