Molecular basis for the regulation of the cardiac delayed rectifier K^+ channel by membrane PIP_2

膜PIP_2调节心脏延迟整流K^通道的分子基础

• 批准号: 17590185
• 负责人: MATSUURA Hiroshi
• 金额: $ 2.3万
• 依托单位: Shiga University of Medical Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17590185/
• 关键词: PIP_2; I_<ks>; α_1-adrenoceptor; P2Y-receptor; hyposmotic solution; membrane stretch; patch-clamp method; action potentials; phenylephrine; PKC; Bisindolylmaleimide I; PKCε

In this research project, we investigated the molecular basis for the regulation of the slowly activating component of delayed rectifier K^+ current (I_<ks>) by membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP_2), using the whole-cell patch-clamp method. The stimulatory action of α_1-adrenergic agonist phenylephrine (30μM) on I_<ks>, was partially (by 60%) inhibited by the protein kinase C inhibitor bisindolylymaleimide I(BIS-I) and was almost totally abolished by intracellular addition of PIP_2 (100μM) through a patch electrode. The potentiation of I_<ks>by the p2Y agonist ATP (50 μM) was scarcely affected by BIS-I but was largely blocked by intracellular application of PIP_2. The stimulation of I_<ks> by exposure to 70% hyposmotic external solution (200 mOsm) was significantly attenuated intracellular application of anti-PIP_2 monoclonal antibody(1:40 dilution) via a patch electrode. These results provide the experimental evidence for the involvement of PIP_2 metabolism in the potentiation of I_<ks>, evoked by stimulation a Gq-phospholipase C (PLC)-coupled receptors (e.g., α_1-and P2Y-receptors) or by hyposmotic cell swelling. The stimulation of M_1-muscarinic receptors (M_1-R) by acetylcholine (1 and 10 nM) in CHO cells transiently trasnfected with KCNQ1, KCNE1 and M_1-R increased the membrane current through the KCNQ1/KCNE1 channels, molecular constituents of cardiac I_<ks>, by 20%, supporting a functional role for membrane PIP_2 in the regulation of I_<ks>. These observation may also indicate the possibility that membrane PIP_2 plays a differential role in the potentiation of I_<ks> through the stimulation of distinct Gq-PLC-coupled receptors or various cellular stimuli.

本研究<ks>采用全细胞膜片钳技术，探讨了膜磷脂磷脂酰肌醇4，5-二磷酸（phosphatidylinositol 4，5-bisphosphate，PIP_2）对延迟整流钾电流（delayed rectifier K^+ current，I_）慢激活成分的调节作用。α_1肾上腺素能激动剂苯肾上腺素（30μM）对I_i的刺激作用<ks>被蛋白激酶C抑制剂双吲哚马来酰亚胺I（BIS-I）部分抑制（60%），并且通过贴片电极在细胞内加入PIP_2（100μM）几乎完全消除。p2 <ks>Y激动剂ATP（50 μM）对I_2的增强作用几乎不受BIS-Ⅰ的影响，但在很大程度上被细胞内应用PIP_2所阻断。用<ks>70%低渗溶液（200 mOsm）刺激I_2，经贴片电极在细胞内应用抗PIP_2单克隆抗体（1：40稀释）可明显减弱I_2的刺激。这些结果为PIP_2代谢参与<ks>刺激Gq-磷脂酶C（PLC）偶联受体（例如，α_1和P2 Y受体）或低渗细胞肿胀。在瞬时转染KCNQ 1、KCNE 1和M_1-R的CHO细胞中，乙酰胆碱（1和10 nM）刺激M_1-R，可使心肌I_2的分子组成KCNQ 1/KCNE 1通道的膜电流<ks>增加20%，支持膜PIP_2在I_2调节中的功能作用<ks>。这些观察结果也可能表明，膜PIP_2通过<ks>刺激不同的Gq-PLC偶联受体或各种细胞刺激物在增强I_2中发挥不同的作用。

项目成果

Stimulatory action of protein kinase Cε isoform on the slow component of delayed rectifier K^+ current in guinea-pig atrial myocytes

蛋白激酶Cε亚型对豚鼠心房肌细胞延迟整流K^+电流慢成分的刺激作用

• 发表时间: 2007
• 期刊: Br J Pharmacol 150
• 作者: Toda H

Inhibitory action of protein kinase C β inhibitor on tetrodotoxin-resistant Na+ current in small dorsal root ganglion neurons in diabetic rats

蛋白激酶Cβ抑制剂对糖尿病大鼠背根小神经节神经元耐河豚毒素Na+电流的抑制作用

• 发表时间: 2007
• 作者: 早瀬 史子

Angiotensin II Potentiates the Slow Component of Delayed Rectifier K+ Current via the AT1 Receptor in Guinea Pig Atrial Myocytes

• DOI: 10.1161/circulationaha.104.530592
• 发表时间: 2006-03
• 期刊: Circulation
• 影响因子: 37.8
• 作者: D. Zankov;M. Omatsu-Kanbe;T. Isono;F. Toyoda;W. Ding;H. Matsuura;M. Horie

心房筋細胞におけるAT1受容体を介した緩徐活性型遅延整流性K+電流(IKs)の増大と活動電位の短縮-心房細動治療におけるAT1受容体遮断薬の有効性との関連

通过心房肌细胞中的 AT1 受体增加慢激活延迟整流 K+ 电流 (IK) 并缩短动作电位 - 与 AT1 受体阻滞剂治疗心房颤动的功效相关

• 发表时间: 2007
• 期刊: 心電図 27
• 作者: Mundia;C. N.;Murayama;Y.;Zankov DP;Zankov DP;Ohno S;Ohno S;Makita N;Ohno S;Sakaguchi T;Nagaoka I;Makiyama T;Ohno S;Toda H;Tsuji K;Itoh H;Horie M;Lu J;Crotti L;Takagi M;堀江 稔;牧山 武;松浦 博
• 通讯作者: 松浦 博

Response to letter regarding article, "Angiotensin II potentiates the slow component of delayed rectifier K^+ current via the AT_1 receptor in guinea pig atrial myocytes".

对有关文章“血管紧张素 II 通过豚鼠心房肌细胞中的 AT_1 受体增强延迟整流 K^ 电流的慢速成分”的信件的回复。

• 发表时间: 2006
• 期刊: Circulation 114
• 作者: Zankov;D.P;Omatsu-Kanbe M.;et al.
• 通讯作者: et al.