Cloning and functional characterization of inwardly rectifying K^+ channels expressed in pancreatic beta-cells

胰腺β细胞中表达的内向整流K^通道的克隆和功能表征

• 批准号: 07671107
• 负责人: INAGAKI Nobuya
• 金额: $ 1.6万
• 依托单位: Chiba University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07671107/
• 关键词: insulin; K^+ channel; sulfonylurea; ATP

In pancreatic beta-cells, ATP-sensitive potassium channels (K_<ATP> channels) are crucial for the regulation of glucoseinduced insulin secretion and are the target for the sulfonylureas, oral hypoglycemic agents widely used in the treatment of non-insulin-dependent diabetes mellitus (NIDDM), but the molecular basis of the K_<ATP> channels was unknown. Recently, a high affinity receptor for sulfonylureas (SUR1), a member of the ATP-binding cassette (ABC) superfamily, has been isolated, but it did not elicit K_<ATP> channel currents. We have cloned a member of the inward rectifier K^+ channel family, uK_<ATP>-1 (Kir6.1), which is expressed in various tissues including pancreatic islets, but not in clonal beta-cell lines. Subsequently, we also have cloned BIR (Kir6.2), which belongs to the same subfamily as Kir6.1 and is expressed predominantly in pancreatic islets and clonal beta-cell lines. We have shown that the properties of the K_<ATP> channel reconstituted from SUR1 and Kir6.2 are those described for native pancreatic beta-cells, demonstrating that the pancreatic beta-cell K_<ATP> channel is a complex composed of Kir6.2 and SUR1. We also have isolated a novel sulfonylurea receptor (SUR2) which shares 68% amino acisd identity with SUR1. SUR2 mRNA is abundant in heart and skeletal muscle. Coexpression of SUR2 and Kir6.2 in COS1 cells reconstitutes K_<ATP> channels found in native cardiac and skeletal muscle, indicating that the pharmacological properties of K_<ATP> channels are determined by a family of sulfonylurea receptor subunits. We also have determined the structure and chromosomal localization of human Kir6.2 gene, and have shown that human SUR1 and Kir6.2 genes are clustered at chromosome 11p15.1. We have found several polymorphysms in the Kir6.2 gene and microsatellite DNA polymorphysms close to the Kir6.2 gene, and have shown that genetic variation in the Kir6.2 gene does not play a major role in susceptibility to NIDDM in Japanese and Caucasian.

在胰β细胞中，对ATP敏感的钾通道（K_ <ATP>通道）对于调节葡萄糖诱导的胰岛素分泌至关重要，并且是磺酰氟烷的靶标，是口服降糖剂，用于非依赖性糖尿病的MOLECERICT ATERPORECTOM的降糖剂（niddm），但是NIDDM的任何> kolotibectem的靶标（但频道未知。最近，已经分离出ATP结合盒（ABC）超家族的成员磺酰氟菌（SUR1）的高亲和力受体，但并未引起K_ <ATP>通道电流。我们已经克隆了一个内向整流器K^+通道家族的成员，UK_________ -1（KIR6.1），该家族在包括胰岛在内的各种组织中表达，但不在克隆β细胞系中表达。随后，我们还克隆了BIR（KIR6.2），该BIR属于与Kir6.1相同的亚科，并且主要在胰岛和克隆β细胞系中表示。我们已经证明，从SUR1和KiR6.2重新生成的K_ <ATP>通道的性质是天然胰腺β细胞所描述的，表明胰腺β-元素K_ <ATP>通道是由KIR6.2和SUR1组成的复合物。我们还分离了一种新型的磺酰脲受体（SUR2），该受体与SUR1共享68％的氨基ACISD身份。 Sur2 mRNA的心脏和骨骼肌丰富。 COS1细胞中SUR2和KIR6.2的共表达在天然心脏和骨骼肌中发现的K_ <ATP>通道，表明K_ <ATP>通道的药理特性由磺酰脲受体亚基的家族确定。我们还确定了人Kir6.2基因的结构和染色体定位，并表明人Sur1和Kir6.2基因聚集在11p15.1染色体上。我们在KIR6.2基因和接近KiR6.2基因的微卫星DNA多晶型物中发现了几个多晶型物，并表明KIR6.2基因的遗传变异在日本和cucasian中NIDDM的易感性中没有主要作用。

项目成果

Namba,N.,et al.: "Kir2.2v : a possible negative regulator of the inwardly rectifying K^+ channel Kir2.2." FEBS lett.386. 211-214 (1996)

Namba,N.,et al.：“Kir2.2v：内向整流 K^ 通道 Kir2.2 的可能负调节因子。”

水田雅也 他: "分子糖尿病学の進歩-基礎から臨床まで-1995" 金原出版, 6 (1995)

Masaya Mizuta 等人：“分子糖尿病的进展 - 从基础知识到临床实践 - 1995” Kanehara Publishing，6 (1995)

Wang, C-Z.et al.: "Cloning and pharmacological characterization of a fourth P2X receptor subtype widely expressed in brain and peripheral tissues including various endocrine tissues." Biochem.Biophys.Res.Commun.220. 196-202 (1996)

Wang, C-Z. 等人：“第四种 P2X 受体亚型的克隆和药理学特征，该亚型广泛表达于大脑和外周组织，包括各种内分泌组织。”

Inagaki,N.et al.: "A family of sulfonylurea receptors determines the pharmacological properties of ATP-sensitive K^+ channels." Neuron. 16. 1011-1017 (1996)

Inagaki,N.et al.：“磺酰脲类受体家族决定了 ATP 敏感 Kk 通道的药理学特性。”

Namba, N.et al.: "Kir2.2v : a possible negative regulator of the inwardly rectifying K^+ channel Kir2.2." FEBS lett.386. 211-214 (1996)

Namba, N.et al.：“Kir2.2v：内向整流 K^ 通道 Kir2.2 的可能负调节因子。”