Structure and function of mitochondrial ATP-sensitive K^+ channel.

线粒体 ATP 敏感 K^ 通道的结构和功能。

• 批准号: 11670080
• 负责人: GONOI Tohru
• 金额: $ 2.43万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670080/
• 关键词: ATP-sensitive K^+ Channel; Mitochondria; Kir6.1; Kir6.2; SUR1; SUR2; Jurkat cell; cAMP-dependent protein kinase; ATP感受性K^+チャネル; 代謝; パッチクランプ法; Kir6.2

ATP-sensitive K^+ (K_<ATP>) channels open and close depending on ATP concentration in the cytoplasm, and control excitability of the cells. We have previously shown that K_<ATP> channel of pancreatic β-cell comprises SUR1, a member of ABC protein, and Kir6.2, a member of inward rectifier K channels. In heart and skeletal muscles, and blood vessels, K_<ATP> channels of similar properties comprise SUR2A/B and Kir6.x, regulating muscle contraction during hypoxia or ischemia.Although similar K_<ATP> channel is expressed in mitochondria, and regulating energy metabolism, its constituting molecules are unknown.Using the patch-clamp technique, we recorded ion channel activity from the mitochondrial inner membrane of Jurkat cells. K^+ ion selective channels with conductance of 55 pS were observed, of which activity being suppressed by 2 mM ATP.These properties and burst kinetics are similar to the channel comprising Kir6.1 molecule. In other to study if Kir6.1 molecules are induced during hypo … More xia, A7r5 cells, derived from blood vessel were cultured in medium containing Co^<2+> ions, mimicking hypoxic conditions. Western blotting using anti Kir6.1 antibody revealed that Kir6.1 protein became expressed in 3-4 days after an addition of the ions. However, no activity of channels comprising activity Kir6.1 was observed in the plasma membrane of heart of blood vessel muscles. Following these results, a possibility that Kir6.1 molecule induced in ischemia composes mitochondrial K_<ATP> channel is currently investigated.In other series of experiments effects of protein kinase A mediated phosphorylation of K_<ATP> channels comprising SUR1 and Kir6.2 were studied. We found both subunits are phosphorylated and channel properties are modulated in a different manner.Finally, effects of anti-diabetic reagents, troglitazone, pioglitazone, and KAD-1229, were studied on reconstituted K_<ATP> channels. The studies are helpful in understanding structure-function relationship of K_<ATP> channels in the plasma membrane as well as mitochondria. Less

ATP 敏感的 K^+ (K_<ATP>) 通道根据细胞质中的 ATP 浓度打开和关闭，并控制细胞的兴奋性。我们之前已经证明胰腺β细胞的K_<ATP>通道包含ABC蛋白成员SUR1和内向整流K通道成员Kir6.2。在心脏、骨骼肌、血管中，性质相似的K_<ATP>通道包括SUR2A/B和Kir6.x，调节缺氧或缺血时的肌肉收缩。虽然类似的K_<ATP>通道在线粒体中表达，调节能量代谢，但其组成分子未知。利用膜片钳技术，我们记录了离子通道 Jurkat 细胞线粒体内膜的活性。观察到电导率为 55 pS 的 K^+ 离子选择性通道，其活性被 2 mM ATP 抑制。这些特性和爆发动力学与包含 Kir6.1 分子的通道相似。在其他研究中，为了研究 Kir6.1 分子是否在缺氧期间被诱导，将源自血管的 A7r5 细胞培养在含有 Co^<2+> 离子的培养基中，模拟缺氧条件。使用抗 Kir6.1 抗体的蛋白质印迹显示，添加离子后 3-4 天，Kir6.1 蛋白开始表达。然而，在血管肌肉的心脏质膜中没有观察到包含活性Kir6.1的通道的活性。根据这些结果，目前正在研究缺血诱导的Kir6.1分子组成线粒体K_<ATP>通道的可能性。在其他系列实验中，研究了蛋白激酶A介导的包含SUR1和Kir6.2的K_<ATP>通道磷酸化的作用。我们发现两个亚基都被磷酸化，通道特性以不同的方式调节。最后，研究了抗糖尿病药物曲格列酮、吡格列酮和 KAD-1229 对重建 K_<ATP> 通道的影响。这些研究有助于理解质膜和线粒体中K_<ATP>通道的结构与功能关系。较少的

项目成果

Sunaga,Y. 他: "Troglitazone but not poiglitazone affects ATP-sensitive K+ channel activity."Eur.J.Pharmacol.. 381. 71-76 (1999)

Sunaga, Y. 等人：“曲格列酮影响 ATP 敏感的 K+ 通道活性，但聚格列酮不影响。”Eur.J.Pharmacol.. 381. 71-76 (1999)

J. Kawaki, T. Gonoi 他: "Unresponsiveness to glibenclamide during chronic treatment induced by reduction of ATP-sensitive K^+ channel activity"Diabetes. 48. 2001-2006 (1999)

J. Kawaki、T. Gonoi 等人：“由于 ATP 敏感性 K^+ 通道活性降低而导致慢性治疗期间对格列本脲无反应”，糖尿病。 48. 2001-2006 (1999)

Sunaga Y, et al.: "Troglitazone but not poiglitazone affects ATP-sensitive K^+ channel activity."Eur.J.Pharmacol.. 381. 71-76 (1999)

Sunaga Y 等人：“曲格列酮而不是聚格列酮影响 ATP 敏感的 Kk 通道活性。”Eur.J.Pharmacol.. 381. 71-76 (1999)

Gonoi T., & Seino, S.: "Structure and function of ATP-sensitive K^+ channels."in Handbook of Experimental Pharmacology "Pharmacology of Ionic Channel Function : Activators and Inhibitors". vol.147, (Edts.M.Endo, Y.Kurachi, M.Mishina)(Springer-Verlag.Berli

戈内 T.,

T.Gonoi, S.Seino 他: "Structure and function of ATP-sensitive K^+ channels. in Handbook of Experimental pharmacology "Pharmacology of Ioninc Channel Function: Activators and Inhibitors" (Edt. Endo, M.)"Springer-Verlag (Berlin). 25 (2000)

T.Gonoi，S.Seino 等人：“ATP 敏感 K^+ 通道的结构和功能。实验药理学手册“离子通道功能的药理学：激活剂和抑制剂”（Edt. Endo，M.）”Springer -出版社（柏林）25（2000）。