Functional interaction of Junctophilin 2 with small- conductance Ca(2+) -activated potassium channel subtype 2(SK2) in mouse cardiac myocytes.
Functional interaction of Junctophilin 2 with small- conductance Ca(2+) -activated potassium channel subtype 2(SK2) in mouse cardiac myocytes.
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小鼠心肌细胞中 Junctophilin 2 与小电导 Ca2 激活钾通道亚型 2 (SK2) 的功能相互作用
DOI：
10.1111/apha.12986
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发表时间：
2018-03
期刊：
影响因子：
--
通讯作者：
Zhang Q
中科院分区：
文献类型：
--
作者：
Fan HK;Luo TX;Zhao WD;Mu YH;Yang Y;Guo WJ;Tu HY;Zhang Q
嗜连接蛋白（Junctophilins，JPs）是连接膜复合物的一个蛋白家族，在横纹肌细胞中维持细胞表面与细胞内膜之间的紧密连接，介导细胞外Ca ~（2+）进入和细胞内Ca ~（2+）释放之间的相互作用。小电导Ca 2+激活的K+通道被细胞内钙激活，在心脏动作电位曲线中起重要作用。SK通道调控的分子机制仍不确定。在这里，我们试图确定是否有junctophilin 2型（JP 2）与SK通道的功能相互作用，以及JP 2基因沉默是否可能调节心肌细胞SK通道的功能。使用体内和体外方法研究了小鼠心脏组织以及HEK 293细胞中JP 2与SK 2通道的关联。通过真实的时间PCR评估JP 2基因的siRNA敲低。Western blotting分析蛋白表达。用全细胞电压钳技术记录感染的成年小鼠心肌细胞中Ca 2+激活的K+电流（I K，Ca）。使用IonOptix光度系统测量细胞内Ca 2+瞬变。我们首次发现JP 2与天然心脏组织中的SK2通道相关。JP 2通过其N端的膜占据和识别关系（MORN基序）直接与SK 2通道相互作用。在心肌细胞中发现了SK2通道与其相互作用蛋白JP 2的共定位。此外，我们证明了JP 2对于HEK 293中SK2通道的适当细胞表面表达是必需的。功能实验表明，JP 2的敲低导致感染的心肌细胞中的I K、Ca密度显著降低，并且降低了Ca 2+瞬变的幅度。目前的数据提供的证据表明，JP 2和SK2通道之间的功能相互作用存在于天然小鼠心脏组织。嗜连接蛋白2（Junctophilin 2）作为连接膜复合物（JMC）蛋白，是心肌SK通道的重要调节因子。
Junctophilins (JPs), a protein family of the junctional membrane complex, maintain the close conjunction between cell surface and intracellular membranes in striate muscle cells mediating the crosstalk between extracellular Ca2+ entry and intracellular Ca2+ release. The small‐conductance Ca2+‐activated K+ channels are activated by the intracellular calcium and play an essential role in the cardiac action potential profile. Molecular mechanisms of regulation of the SK channels are still uncertain. Here, we sought to determine whether there is a functional interaction of junctophilin type 2 (JP2) with the SK channels and whether JP2 gene silencing might modulate the function of SK channels in cardiac myocytes. Association of JP2 with SK2 channel in mouse heart tissue as well as HEK293 cells was studied using in vivo and in vitro approaches. siRNA knockdown of JP2 gene was assessed by real‐time PCR. The expression of proteins was analysed by Western blotting. Ca2+‐activated K+ current (I K,Ca) in infected adult mouse cardiac myocytes was recorded using whole‐cell voltage‐clamp technique. The intracellular Ca2+ transient was measured using an IonOptix photometry system. We showed for the first time that JP2 associates with the SK2 channel in native cardiac tissue. JP2, via the membrane occupation and recognition nexus (MORN motifs) in its N‐terminus, directly interacted with SK2 channels. A colocalization of the SK2 channel with its interaction protein of JP2 was found in the cardiac myocytes. Moreover, we demonstrated that JP2 is necessary for the proper cell surface expression of the SK2 channel in HEK293. Functional experiments indicated that knockdown of JP2 caused a significant decrease in the density of I K,Ca and reduced the amplitude of the Ca2+ transient in infected cardiomyocytes. The present data provide evidence that the functional interaction between JP2 and SK2 channels is present in the native mouse heart tissue. Junctophilin 2, as junctional membrane complex (JMC) protein, is an important regulator of the cardiac SK channels.
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DOI：
10.1161/circheartfailure.110.958694
发表时间：
2011-03
期刊：
Circulation. Heart failure
影响因子：
--
作者：
Landstrom AP;Kellen CA;Dixit SS;van Oort RJ;Garbino A;Weisleder N;Ma J;Wehrens XH;Ackerman MJ
通讯作者：
Ackerman MJ
影响因子：
20.1
作者：
Chua SK;Chang PC;Maruyama M;Turker I;Shinohara T;Shen MJ;Chen Z;Shen C;Rubart-von der Lohe M;Lopshire JC;Ogawa M;Weiss JN;Lin SF;Ai T;Chen PS
通讯作者：
Chen PS
影响因子：
4.8
作者：
Golini, Lucia;Chouabe, Christophe;Sorrentino, Vincenzo
通讯作者：
Sorrentino, Vincenzo
影响因子：
4.6
作者：
Garbino, Alejandro;van Oort, Ralph J.;Wehrens, Xander H. T.
通讯作者：
Wehrens, Xander H. T.
DOI：
10.1111/j.1749-6632.1999.tb11298.x
发表时间：
1999-01-01
期刊：
MOLECULAR AND FUNCTIONAL DIVERSITY OF ION CHANNELS AND RECEPTORS
影响因子：
--
作者：
Bond, CT;Maylie, J;Adelman, JP
通讯作者：
Adelman, JP