MULTIPLE CONNEXINS COLOCALIZE IN CANINE VENTRICULAR MYOCYTE GAP-JUNCTIONS
MULTIPLE CONNEXINS COLOCALIZE IN CANINE VENTRICULAR MYOCYTE GAP-JUNCTIONS
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DOI：
10.1161/01.res.73.2.344
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发表时间：
1993-08-01
影响因子：
20.1
通讯作者：
SAFFITZ, JE
中科院分区：
文献类型：
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作者：
KANTER, HL;LAING, JG;SAFFITZ, JE
我们最近发现，成年犬心室肌细胞表达三种不同的间隙连接通道蛋白，connexin40 （Cx40）、connexin43 （Cx43）和connexin45 （Cx45）。这些蛋白具有独特的细胞质结构域，可能赋予连接蛋白特异性生理特性。为了确定这三种不同的通道蛋白是否分布在相同或不同的间隙连接群体中，我们对分离的犬心室肌细胞进行了双标记免疫荧光，同时用小鼠单克隆抗cx43和亲和纯化的兔抗Cx40或Cx45的多克隆抗体孵育。使用激光扫描共聚焦显微镜分析双标记心肌细胞显示Cx43/Cx40和Cx43/Cx45对几乎相同的免疫反应性模式。双标记免疫电镜证实超微结构鉴定的心肌细胞间隙连接含有多种通道蛋白。因此，三种通道蛋白在犬心肌细胞间隙连接中共定位。多种功能不同的连接蛋白的存在表明，单个通道的组成和细胞间偶联的调节存在复杂的可能性。
We have recently shown that adult canine ventricular myocytes express three distinct gap junction channel proteins, connexin40 (Cx40), connexin43 (Cx43), and connexin45 (Cx45). These proteins have unique cytoplasmic domains that likely confer connexin-specific physiological properties. To determine whether the three distinct channel proteins are distributed in identical or different populations of gap junctions, we performed double-label immunofluorescence on disaggregated canine ventricular myocytes incubated simultaneously with a mouse monoclonal anti-Cx43 and affinity-purified polyclonal rabbit antibodies against Cx40 or Cx45. Analysis of double-labeled cardiac myocytes using laser scanning confocal microscopy revealed virtually identical patterns of immunoreactivity for both the Cx43/Cx40 and Cx43/Cx45 pairs. Double-label immunoelectron microscopy confirmed that ultrastructurally identified cardiac myocyte gap junctions contain multiple channel proteins. Thus, three channel proteins colocalize in canine cardiac myocyte gap junctions. The presence of multiple functionally distinct connexins suggests complex possibilities regarding the composition of individual channels and the regulation of intercellular coupling.