Functional analysis of a dominant mutation of human connexin26 associated with nonsyndromic deafness
Functional analysis of a dominant mutation of human connexin26 associated with nonsyndromic deafness
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DOI：
10.3109/15419060109080765
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发表时间：
2001-01-01
影响因子：
--
通讯作者：
White, TW
中科院分区：
文献类型：
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作者：
Bruzzone, R;Gomès, D;White, TW
Cx26 与显性 (DFNA3) 和隐性 (DFNB1) 形式的非综合征性感音神经性耳聋有关。虽然大多数 DFNB1 Cx26 纯合突变仅导致通道活性丧失，但与 DFNA3 相关的 Cx26 杂合突变如何导致听力损失尚不清楚。我们测试了一种显性突变 (W44C) 干扰野生型人类 Cx26 (HCx26wt) 的能力。 HCx26wt 在配对卵母细胞之间诱导强大的电导，并促进转染的 HeLa 细胞之间的染料转移。相比之下。仅注射 W44C 的卵母细胞对的电耦合不高于背景水平，并且 W44C 未能对转染的 HeLa 细胞进行染色耦合。此外，当以相等比例共表达时，W44C 显着抑制 HCx26wt 的细胞间电导，并且低水平的残余电导显示出改变的门控特性。当共注射到相同卵母细胞对中时，非功能性隐性突变 (W77R) 不会抑制 HCx26wt 形成功能性通道的能力，也不会改变 HCx26wt 门控。这些结果为 W44C 突变体对 HCx26wt 的功能显性负效应提供了证据，并解释了杂合 Cx26 突变如何通过导致 Cx26 功能的净损失和/或改变而导致常染色体显性耳聋。
Cx26 has been implicated in dominant (DFNA3) and recessive (DFNB1) forms of nonsyndromic sensorineural deafness. While most homozygous DFNB1 Cx26 mutations result in a simple loss of channel activity, it is less clear how heterozygous mutations in Cx26 linked to DFNA3 cause hearing loss. We have tested the ability of one dominant mutation (W44C) to interfere with wild-type human Cx26 (HCx26wt). HCx26wt induced robust electrical conductance between paired oocytes, and facilitated dye transfer between transfected HeLa cells. In contrast. oocyte pairs injected with only W44C were not electrically coupled above background levels, and W44C failed to dye couple transfected HeLa cells. Moreover, W44C dramatically inhibited intercellular conductance of HCx26wt when co-expressed in an equal ratio, and the low levels of residual conductance displayed altered gating properties. A nonfunctional recessive mutation (W77R) did not inhibit the ability of HCx26wt to form functional channels when co-injected in the same oocyte pairs, nor did it alter HCx26wt gating. These results provide evidence for a functional dominant negative effect of the W44C mutant on HCx26wt and explain how heterozygous Cx26 mutations could contribute to autosomal dominant deafness, by resulting in a net loss, and/or alteration, of Cx26 function.