Connexin37 forms high conductance gap junction channels with subconductance state activity and selective dye and ionic permeabilities.
Connexin37 forms high conductance gap junction channels with subconductance state activity and selective dye and ionic permeabilities.
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Connexin37 形成具有亚电导状态活性和选择性染料和离子渗透性的高电导间隙连接通道。
DOI：
10.1016/s0006-3495(94)80985-3
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发表时间：
1994
影响因子：
3.4
通讯作者：
Brink,PR
中科院分区：
文献类型：
--
作者：
Veenstra,RD;Wang,HZ;Beyer,EC;Ramanan,SV;Brink,PR
间隙连接被认为通过可渗透直径高达 1 kDa 或 10-14 A 的离子和分子的水孔的开闭门控来介导相邻细胞的直接细胞间耦合。我们对称地改变离子组成或不对称添加 6-羧基荧光素 (6-CF, M(r) = 376)（一种荧光示踪剂）到成对的 connexin37 转染的小鼠 Neuro2A 细胞中，以检查人 connexin37 通道的离子和染料通透性。我们证明，由 connexin37 形成的 300-pS 通道具有 0.43 的有效相对阴离子/阳离子渗透率比，直接转换为至少一种中间 (63 pS) 亚电导状态，并且 6-CF 染料转移伴随着单位通道电导下降 24%。这些观察结果支持对间隙连接孔的新解释，该解释与更传统的多态离子通道常见的直接离子通道相互作用或静电荷效应一致。这些结果对于根据连接蛋白通道蛋白的表达和构象而发生的不同形式的细胞间信号传导（阳离子、离子和/或生化）具有明显的意义。
Gap junctions are thought to mediate the direct intercellular coupling of adjacent cells by the open-closed gating of an aqueous pore permeable to ions and molecules of up to 1 kDa or 10–14 A in diameter. We symmetrically altered the ionic composition or asymmetrically added 6-carboxyfluorescein (6-CF, M(r) = 376), a fluorescent tracer, to pairs of connexin37-transfected mouse neuro2A cells to examine the ionic and dye permeability of human connexin37 channels. We demonstrate that the 300-pS channel formed by connexin37 has an effective relative anion/cation permeability ratio of 0.43, directly converts to at least one intermediate (63 pS) subconductance state, and that 6-CF dye transfer is accompanied by a 24% decrease in unitary channel conductance. These observations favor a new interpretation of the gap junction pore consistent with direct ion-channel interactions or electrostatic charge effects common to more conventional multistate ion channels. These results have distinct implications about the different forms of intercellular signaling (cationic, ionic, and/or biochemical) that can occur depending on the expression and conformation of the connexin channel proteins.