Pinacidil,a K_(atp) channel opener,identified as a novel agonist for TRPA1  

作　　者：MA LiangHui DENG Ying ZHANG Bi BAI YanQiu CAO Jing LI ShiYou LIU JianFeng 

机构地区：[1]Beijing Institute of Genomics,Chinese Academy of Sciences,Beijing 100029,China [2]Graduate University of Chinese Academy of Sciences,Beijing 100049,China [3]Shanghai Jiao Tong University,Shanghai 200240,China [4]Sino-France Laboratory for Drug Screening,Key Laboratory of Molecular Biophysics of Ministry of Education,School of Life Science and Technology,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Chinese Science Bulletin》2012年第15期1810-1817,共8页

基　　金：supported by grants from the Ministry of Science and Technology (2007CB914200 and 2010DFA32140);the National Natural Science Foundation of China(31130028 and 30973514);Program of Introducing Talents of Discipline to Universities of Ministry of Education (B08029)

摘　　要：The transient receptor potential Ankyrin 1(TRPA1) cation channel is activated by various pungent and irritant compounds,and it also mediates the perception of noxious cold.Identification of different agonists for this channel is important for understanding its activation mechanism.Therefore,a screen for novel TRPA1 agonists was performed using an agonist-induced calcium influx assay.Out of 90 compounds screened,pinacidil was identified as a novel agonist for this channel.Pinacidil is a known opener of the K atp channel,for which it has an EC50 value of 1-3 μmol/L.In comparison,the EC50 value of pinacidil for TRPA1 is relatively high(260 μmol/L).Recombinant HEK-TRPA1 cells did not respond to P1075,another K atp channel opener,suggesting that the effect of pinacidil on TRPA1 was highly specific.Further studies revealed that the agonist activity of pinacidil could be blocked by the TRP channel inhibitors,ruthenium red and HC-030031.Using glutathione(GSH) and site-specific mutagenesis,we demonstrated that pinacidil could activate TRPA1 by covalent modification of the critical amino acids C619,C639 and C663 in the N-terminus of TRPA1.The transient receptor potential Ankyrin 1 （TRPA1） cation channel is activated by various pungent and irritant compounds, and it also mediates the perception of noxious cold. Identification of different agonists for this channel is important for understanding its activation mechanism. Therefore, a screen for novel TRPA1 agonists was performed using an agonist-induced calcium influx assay. Out of 90 compounds screened, pinacidil was identified as a novel agonist for this channel. Pinacidil is a known opener of the Katp channel, for which it has an EC50 value of 1-3 μmol/L. In comparison, the EC50 value of pinacidil for TRPAI is relatively high （260 μmol/L）. Recombinant HEK-TRPA1 cells did not respond to P1075, another Katp channel opener, suggesting that the effect of pinacidil on TRPA1 was highly specific. Further studies revealed that the agonist activity of pinacidil could be blocked by the TRP channel inhibitors, ruthenium red and HC-030031. Using glutathione （GSH） and site-specific mutagenesis, we demonstrated that pinacidil could activate TRPA1 by covalent modification of the critical amino acids C619, C639 and C663 in the N-terminus of TRPA 1.

关 键 词：ATP敏感性钾通道 受体激动剂 还原型谷胱甘肽 EC50值 激活机制 KATP通道 位点特异性 离子通道 

分 类 号：R33[医药卫生—人体生理学]