Stabilization of ion channel protein by regulation of proteasome and its application to the individualizing atrial fibrillation.

通过蛋白酶体调节稳定离子通道蛋白及其在个体化心房颤动中的应用。

• 批准号: 15590747
• 负责人: HISATOME Ichiro
• 金额: $ 2.24万
• 依托单位: National University Corporation Tottori University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15590747/
• 关键词: atrial fibrillation; ion channel; ubiquitin-proteasome; Na^+ channel blockers; SNPs; ユビキチン・プロテアソーム; Na channel 阻害剤; 蛋白安定化; Kv1.5; HSP70; ユビキチン化; 細胞内トラフィック; 小胞体品質管理機構

Background : Previously we reported that ion channels responsible for chronic atrial fibrillation have been degraded by ubiquitin-proteasome, which was modification by antiarrhythmic agents. In the current study, we elucidated its underlying mechanism and application to the individualizing therapy for atrial fibrillation.Methods and Results : Na^+ channel blockers, but not either Ca^<2+> antagonists or K^+ channel blockers, blocked 20S proteasome activity to stabilize the short-lived proteins including p53,IKK2 and Kv1.5 assessed by pulse-chase analysis, immnofluorescence and patch clamp techniques in transfected COS cells. To confirm that p53 stabilization by Na^+ channel blockers was secondary to proteasome inhibition, we examined whether Mdm2 (C438A) could block the drug effects. When co-expressed with Mdm2 (C438A), p53-FLAG was not at all ubiquitinated even when cells were treated with MG132 and this drug failed to increase the p53-FLAG protein level. Likewise, p53-FLAG was not ubiquitinated in cells treated with Na^+ channel blockers, which failed to increase the protein level. Na^+ channel blockers stabilized the short-lived Kir6.2 channel proteins like MG132. There were several SNPs on the lysine residues in the coding region of Kir6.2, suggesting SNPs can affect the extent of channel protein degradation.Conclusion : Expression of short-lived ion channels have been regulated by ubiquitin-proteasome, which can be modulated by Na^+ channel blockers. Based on the SNPs information, a pharmacological therapy to regulate proteasomal degradation of channel protein can be available for treating the patients with chronic atrial fibrillation.

背景资料：以前我们曾报道过，慢性心房颤动的离子通道被泛素-蛋白酶体降解，而这种酶体被抗心律失常药物修饰。本研究旨在阐明其潜在机制，并探讨其在房颤个体化治疗中的应用。方法与结果：Na^+通道阻断剂（而非Ca^2+拮抗剂或K^+通道阻断剂）可阻断20 S蛋白酶体活性，从而稳定包括p53、IKK 2和Kv 1.5在内的短寿命蛋白质（通过脉冲追踪分析评估），免疫荧光和膜片钳技术。为了证实Na^+通道阻断剂对p53的稳定作用是继发于蛋白酶体抑制的，我们检测了Mdm 2（C438 A）是否可以阻断药物作用。当与Mdm 2（C438 A）共表达时，即使当细胞用MG 132处理时，p53-FLAG也根本不被泛素化，并且该药物不能增加p53-FLAG蛋白水平。同样，在用Na^+通道阻断剂处理的细胞中，p53-FLAG也没有被泛素化，这也不能提高蛋白水平。Na^+通道阻断剂可以稳定短寿命的Kir6.2通道蛋白，如MG 132。结论：短寿命离子通道的表达受泛素-蛋白酶体的调控，Na^+通道阻断剂可调控短寿命离子通道的表达。基于SNPs信息，调节通道蛋白的蛋白酶体降解的药物治疗可用于治疗慢性房颤患者。

项目成果

心筋型ATP感受性Kチャンネルはユビキチン/プロテアソーム系により機能性チャンネル蛋白が規定される。

心脏 ATP 敏感 K 通道的功能通道蛋白由泛素/蛋白酶体系统定义。

• 发表时间: 2004
• 期刊: 心電図 24
• 作者: Kurata Y;et al.;田中宏明
• 通讯作者: 田中宏明

Roles of L-type Ca2+ and delayed-rectifier K+ currents in sinoatrial node pacemaking:: insights from stability and bifurcation analyses of a mathematical model

• DOI: 10.1152/ajpheart.01050.2002
• 发表时间: 2003-12-01
• 期刊: AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
• 影响因子: 4.8
• 作者: Kurata, Y;Hisatome, I;Shibamoto, T
• 通讯作者: Shibamoto, T

State-dependent blocking actions of azimilide dihydrochlo-ride (NE-10064) on human cardiac Na(+) channels.

阿齐利特二盐酸盐 (NE-10064) 对人心脏 Na(+) 通道的状态依赖性阻断作用。

• 发表时间: 2004
• 期刊: Circ J. 68(7)
• 作者: Miake J;et al.
• 通讯作者: et al.

Okamura T, et al.: "Abnormally High Expression of Proteasome Activator-gamma in Thyroid Neoplasm"The Journal of Clinical Endocrinology and Metabolism. 88(3). 1374-1383 (2003)

Okamura T 等人：“甲状腺肿瘤中蛋白酶体激活剂-γ 的异常高表达”《临床内分泌与代谢杂志》。

Detection of the novel autoantibody (anti-UACA antibody) in patients with Graves' disease.

• DOI: 10.1016/j.bbrc.2004.06.162
• 发表时间: 2004-08
• 期刊: Biochemical and biophysical research communications
• 影响因子: 3.1
• 作者: T. Ohkura;Shin‐ichi Taniguchi;Kazuhiro Yamada;N. Nishio;T. Okamura;Akio Yoshida;Keiichi Kamijou;S. Fukata;K. Kuma;Y. Inoue;I. Hisatome;S. Senju;Y. Nishimura;C. Shigemasa