Sosinsky G
Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02254-9110, USA.
Proc Natl Acad Sci U S A. 1995 Sep 26;92(20):9210-4. doi: 10.1073/pnas.92.20.9210.
Gap junctions are plaque-like clusters of intercellular channels that mediate intercellular communication. Each of two adjoining cells contains a connexon unit which makes up half of the whole channel. Gap junction channels are formed from a multigene family of proteins called connexins, and different connexins may be coexpressed by a single cell type and found within the same plaque. Rodent gap junctions contain two proteins, connexins 32 and 26. Use of a scanning transmission electron microscope for mass analysis of rodent gap junction plaques and split gap junctions prvided evidence consistent with a model in which the channels may be made from (i) solely connexin 26, (ii) solely connexin 32, or (iii) mixtures of connexin 26 and connexin 32 in which the two connexons are made entirely of connexin 26 and connexin 32. The different types of channels segregate into distinct domains, implying tha connexon channels self-associate to give a non-random distribution within tissues. Since each connexin confers distinct physiological properties on its membrane channels, these results imply that the physiological properties of channels can be tailored by mixing the constituent proteins within these macromolecular structures.
间隙连接是介导细胞间通讯的细胞间通道的斑块状簇。两个相邻细胞中的每一个都包含一个连接子单元，它构成了整个通道的一半。间隙连接通道由称为连接蛋白的多基因家族蛋白质形成，并且不同的连接蛋白可能由单一细胞类型共表达并存在于同一斑块中。啮齿动物的间隙连接包含两种蛋白质，连接蛋白32和26。使用扫描透射电子显微镜对啮齿动物间隙连接斑块和分裂间隙连接进行质量分析，提供了与以下模型一致的证据：通道可能由（i）仅连接蛋白26、（ii）仅连接蛋白32或（iii）连接蛋白26和连接蛋白32的混合物制成，其中两个连接子完全由连接蛋白26和连接蛋白32制成。不同类型的通道分隔成不同的区域，这意味着连接子通道自我缔合以在组织内产生非随机分布。由于每种连接蛋白赋予其膜通道不同的生理特性，这些结果表明通道的生理特性可以通过在这些大分子结构中混合组成蛋白来定制。
