Department of Pediatrics, Division of Neurology, The Children's Hospital of Philadelphia, USA.
Mol Cell Neurosci. 2011 Jun;47(2):71-8. doi: 10.1016/j.mcn.2010.10.002. Epub 2010 Oct 30.
Mutations in GJB2, the gene encoding the human gap junction protein connexin26 (Cx26), cause either non-syndromic hearing loss or syndromes affecting both hearing and skin. We have investigated whether dominant Cx26 mutants can interact physically with wild type Cx26. HeLa cells stably expressing wild type Cx26 were transiently transfected to co-express nine individual dominant Cx26 mutants; six associated with non-syndromic hearing loss (W44C, W44S, R143Q, D179N, R184Q, and C202F) and three associated with hearing loss and palmoplantar keratoderma (G59A, R75Q, and R75W). All mutants co-localized and co-immunoprecipitated with wild type Cx26, indicating that they interact physically, likely by forming admixed heteromeric/heterotypic channels. Furthermore, all nine mutants inhibited the transfer of calcein in cells stably expressing Cx26, demonstrating that they each have dominant effects on wild type Cx26. Taken together, these results show that dominant-negative effects of these Cx26 mutants likely contribute to the pathogenesis of hearing loss.
GJB2 基因突变导致人类缝隙连接蛋白 connexin26（Cx26），引起非综合征性听力损失或同时影响听力和皮肤的综合征。我们研究了显性 Cx26 突变体是否可以与野生型 Cx26 发生物理相互作用。稳定表达野生型 Cx26 的 HeLa 细胞瞬时转染以共表达九个个体显性 Cx26 突变体；六个与非综合征性听力损失相关（W44C、W44S、R143Q、D179N、R184Q 和 C202F），三个与听力损失和掌跖角化症相关（G59A、R75Q 和 R75W）。所有突变体与野生型 Cx26 共定位和共免疫沉淀，表明它们发生物理相互作用，可能通过形成混合异源/异型通道。此外，所有九个突变体均抑制稳定表达 Cx26 的细胞中 calcein 的转移，表明它们各自对野生型 Cx26 具有显性效应。总之，这些结果表明这些 Cx26 突变体的显性负效应可能导致听力损失的发病机制。
