Characterization of Sodium Channel α- and β-Subunits in Rat and Mouse Cardiac Myocytes
Characterization of Sodium Channel α- and β-Subunits in Rat and Mouse Cardiac Myocytes
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DOI：
10.1161/01.cir.103.9.1303
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发表时间：
2001-03
期刊：
影响因子：
37.8
通讯作者：
J. Malhotra;Chunling Chen;I. Rivolta;Hugues Abriel;R. Malhotra;L. N. Mattei;F. Brosius;R. Kass;L. Isom
中科院分区：
文献类型：
--
作者：
J. Malhotra;Chunling Chen;I. Rivolta;Hugues Abriel;R. Malhotra;L. N. Mattei;F. Brosius;R. Kass;L. Isom
从哺乳动物脑中分离的钠通道由α-、β1-和β2-亚基组成。然而，心肌中钠通道的组成尚未确定，并且对于哪些β亚基在肌细胞中表达存在分歧。一些研究者已经证实β1在心脏中表达。其他人没有检测到任何辅助亚基。基于总RNA的北方印迹分析，β2表达被认为是神经元专有的，而在心肌中不存在。方法和结果-本研究的目的是确定心肌细胞中心脏钠通道的亚基组成。我们发现心脏钠通道由α-、β1-和β2-亚基组成。Nav1.5和Nav1.1在肌细胞中表达，并与β1-和β2-亚基相关。Nav1.1、β1和β2在成人心脏切片中的免疫细胞化学定位显示，这些亚基在Z线表达，如先前Nav1.5所示。Nav1.5与β2在转染细胞中的共表达
Background—Sodium channels isolated from mammalian brain are composed of α-, β1-, and β2-subunits. The composition of sodium channels in cardiac muscle, however, has not been defined, and disagreement exists over which β-subunits are expressed in the myocytes. Some investigators have demonstrated β1 expression in heart. Others have not detected any auxiliary subunits. On the basis of Northern blot analysis of total RNA, β2 expression has been thought to be exclusive to neurons and absent from cardiac muscle. Methods and Results—The goal of this study was to define the subunit composition of cardiac sodium channels in myocytes. We show that cardiac sodium channels are composed of α-, β1-, and β2-subunits. Nav1.5 and Nav1.1 are expressed in myocytes and are associated with β1- and β2-subunits. Immunocytochemical localization of Nav1.1, β1, and β2 in adult heart sections showed that these subunits are expressed at the Z lines, as shown previously for Nav1.5. Coexpression of Nav1.5 with β2 in transfected cell...