Voltage-gated potassium (K(V)) channels are modulated by at least three distinct classes of proteins including the KCNE family of single transmembrane accessory subunits. In the human genome, KCNE proteins are encoded by five genes designated KCNE1 through KCNE5. KCNE1 associates with KCNQ1 in vitro to generate a potassium current closely resembling the slowly activating delayed rectifier (I(Ks)). Other KCNE proteins also affect the activity of heterologously expressed KCNQ1. To investigate the potential physiological relevance of this gene family in human heart, we examined the relative expression of KCNQ1 and all five KCNE genes in samples derived from normal tissues representing major regions of human heart by real-time, quantitative RT-PCR. KCNE genes are expressed in human heart with a relative abundance ranking of KCNE1 > KCNE4 > KCNE5 approximately KCNE3 >> KCNE2. In situ hybridization revealed prominent expression of KCNE1 and KCNE3-5 in human atrial myocytes. In cardiomyopathic hearts, expression of KCNE1, KCNE3, KCNE4, and KCNQ1 was significantly increased, while KCNE2 and KCNE5 exhibited reduced expression. In a cell line stably expressing KCNQ1 and KCNE1, transient expression of KCNE3, KCNE4, or KCNE5 significantly altered I(Ks) current profiles. Even in the presence of additional KCNE1, KCNE4 and KCNE5 exert dominant effects on I(Ks). Although KCNE1 is the predominant KCNE family member expressed in human heart, the abundance of other KCNE transcripts including potential KCNQ1 suppressors (KCNE4 and KCNE5) and their altered expression patterns in disease lead us to speculate that a balance of KCNE accessory subunits may be important for cardiac K(V) channel function.

中文翻译：

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人心脏中多个KCNE基因的表达可以实现I（Ks）的可变调节。

电压门控钾（K（V））通道受至少三类不同的蛋白调节，包括单跨膜附件亚基的KCNE家族。在人类基因组中，KCNE蛋白由五个命名为KCNE1至KCNE5的基因编码。KCNE1在体外与KCNQ1结合，以产生与缓慢激活的延迟整流器（I（Ks））非常相似的钾电流。其他KCNE蛋白也影响异源表达的KCNQ1的活性。为了研究该基因家族在人心脏中的潜在生理相关性，我们通过实时定量RT-PCR检查了代表人体心脏主要区域的正常组织样品中KCNQ1和所有五个KCNE基因的相对表达。KCNE基因在人心中表达，相对丰度等级为KCNE1> KCNE4> KCNE5约为KCNE3 >> KCNE2。原位杂交揭示了人心房肌细胞中KCNE1和KCNE3-5的显着表达。在心肌病患者的心脏中，KCNE1，KCNE3，KCNE4和KCNQ1的表达明显增加，而KCNE2和KCNE5的表达减少。在稳定表达KCNQ1和KCNE1的细胞系中，KCNE3，KCNE4或KCNE5的瞬时表达显着改变了I（Ks）电流分布。即使存在额外的KCNE1，KCNE4和KCNE5也会对I（Ks）发挥主要作用。尽管KCNE1是人类心脏中表达的主要KCNE家族成员，