Elucidation of the mechanisms underlying the regulation of ATP-sensitive K^+ channels by sulfonylureas

阐明磺酰脲类药物调节 ATP 敏感 K^ 通道的机制

• 批准号: 09671025
• 负责人: INAGAKI Nobuya
• 金额: $ 2.3万
• 依托单位: Akita University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09671025/
• 关键词: sulfonylurea; ATP-sensitive K^* channel; inward rectifier K^* channel; knockout mouse; pancreatic beta-cell; ABC protein; cardiac myocyte; スルホニル尿素; ATP感受性Kチャネル; ATP; イオンチャネル; インスリン

ATP-sensitive K^+(K_<ATP>) channels are key molecules which link the cell's metabolic status to its membrane potential. In pancreatic beta-cells, KK_<ATP> channel is not only a glucose sensor m insulin secretion but also a target for the insulin secretagogue, the sulfonylurea, widely used as oral hypoglycemic agents in the treatment of diabetes mellitus. In cardiac myocytes and neurons, K_<ATP> channels are supposed to be involved in cytoprotection in ischemia, We have shown that beta-cell K_<ATP> channel is a complex of the sulfonylurea receptor SURI and a newly cloned inward rectifier K_<ATP> channel member Kir6.2, and that cardiac myocyte K_<ATP> channel is a complex of the newly cloned sulfonylurea receptor SUR2 and the Kir6.2. Our purpose in this study is to clarify the molecular mechanisms underlying the regulation of K^+ channels.Sensitivities of the [3-cell (SUR1/Kir6.2) and cardiac (SUR2/Kir6.2) K_<ATP> channels to the sulfonylurea glibenclamide and the K_<ATP> channel opener … More diazoxide are different, and are determined by distinct SUR subunits. To determine the domains that confer glibenclamide and diazoxide sensitivities, we prepared a series of chimeras between SUR1 and SUR2, and studied the properties of the chimeric K_<ATP> channels. All chimeric SURs could generate currents when expressed in COS 1 cells with Kir6.2. Next, we have examined the effects of the glibenclamide and diazoxide on the chimeric currents measured as ^<86>Rb^+ efflux, and narrowed the region that confer the sensitivities to these reagents. Furthermore, we have constructed various chimeras between SUR1 and SUR2, and have almost determined the glibenclamide-responsive region by measuring the binding activities of @SH-labeled glibenclamide for the chimeras expressed in COS 1 cells (manuscript in 3@E1preparation).In addition, we have investigated the effects of G-protein on the reconstituted K_<ATP> channels. We have shown that G-protein alpha subunit directly regulates the K_<ATP> channel activity, and that the regulation is different between [3-cell (SUR1/Kir6.2) and cardiac (SUR2/Kir6.2) K_<ATP> channels, suggesting that the difference is determined by distinct SUR subunits. Less

ATP敏感的K^+（K_ <ATP>）通道是关键分子，将细胞的代谢状态与其膜电位联系起来。在胰腺β细胞中，KK_ <ATP>通道不仅是葡萄糖传感器M胰岛素分泌，而且还是胰岛素秘密的靶标，磺酰尿素，磺酸碱，广泛用作糖尿病治疗的口服低血糖药物。在心肌细胞和神经元中，k_ <ATP>频道有望参与缺血中的细胞保护作用，我们表明beta-cell k_ <ATP>频道是Sulfonylurea受体Suri的综合体，是Sulfonylurea受体Suri的复杂性，并且是一个新的Cronewer Rectifier K_ <ATP> Channel k_ <ATP> channel kir6.2和kir6.2 and kir6.2 and kir6.2 and kir6.2和kir <克隆的磺酰脲受体SUR2和KIR6.2。我们在这项研究中的目的是澄清调节K^+通道的分子机制。[3-cell（SUR1/KIR6.2）和心脏（SUR2/KIR6.2）K_ <ATP>通道的敏感性与SuloDylurea Glibenclamide和K_ <sullys sun suns sulter and sulzoxide不同的是与DIAZOXIDER不同的sul and suls and suls and sulziDIDE，并且是不同的。为了确定会议Glibenclamide和二氮氧化物灵敏度的域，我们准备了Sur1和Sur2之间的一系列嵌合体，并研究了嵌合K_ <ATP>通道的性质。当用KiR6.2在COS 1细胞中表达时，所有嵌合Surs都可以产生电流。接下来，我们检查了Glibenclamide和二氮氧化物对测量为 ^<86> rb ^+外排的嵌合电流的影响，并范围缩小了对这些试剂的敏感性的区域。此外，我们已经在SUR1和SUR2之间构建了各种嵌合体，几乎通过测量 @sh-sh-sh-sh-sh-labeLed glibenclamide的结合活性来确定glibenclamide响应性区域，用于在cos 1细胞中表达的嵌合体（在3 @e1prepreparation中以3 @e1preparation中的手稿）进行了调查，我们已经调查了对g态蛋白的效果。我们已经表明，G蛋白α亚基直接调节K_ <ATP>通道活性，并且调节在[3-cell（SUR1/KIR6.2）和心脏（SUR2/KIR6.2）K_ <ATP>通道之间是不同的，这表明该差异是由不同的Sur-surunitits确定的。较少的

项目成果

Inagaki, N.: "Diabetes mellitau and KATP channels" Diagnosis and Treatment. 86. 2085-2090 (1998)

Inagaki, N.：“糖尿病和 KATP 通道”诊断和治疗。

Miki,T., Inagaki,N., et al.: "Abnormalities of pancreatic islets by targetted expression of dominant-negative K_<ATP> channel." Proc. Natl, Acad. Aci, USA.94. 11969-11973 (1997)

Miki,T.、Inagaki,N. 等人：“显性失活 K_<ATP> 通道的靶向表达导致胰岛异常。”

稲垣暢也: "糖尿病とK_<ATP2>チャネル." 診断と治療. 86. 2085-2090 (1998)

Nobuya Inagaki：“糖尿病和 K_<ATP2> 诊断和治疗”。86。2085-2090 (1998)

稲垣暢也: "ATP感受性K^+チャネル" 医学のあゆみ. 188. 309-313 (1999)

Nobuya Inagaki：“ATP 敏感 K^+ 通道”医学史 188. 309-313 (1999)。

Sanchez,J.A.,Gonoi,Y.,Inagaki,N.,Katada,T.,and Seino,S.: "Modulation of reconstituted ATP-sensitive K^+ channels by GTP-binding proteins." J.Physiol.507. 315-324 (1998)

Sanchez,J.A.、Gonoi,Y.、Inagaki,N.、Katada,T. 和 Seino,S.：“GTP 结合蛋白对重建 ATP 敏感 K^ 通道的调节”。