PDF(Pubmed)
Abstract：
Pendrin and prestin are evolutionary-conserved membrane proteins that are essential for normal hearing. Dysfunction of these proteins results in hearing loss in humans, and numerous deafness-associated pendrin and prestin variants have been identified in patients. However, the pathogenic impacts of many of these variants are ambiguous. Here, we report results from our ongoing efforts to experimentally characterize pendrin and prestin variants using in vitro functional assays. With previously established fluorometric anion transport assays, we determined that many of the pendrin variants identified on transmembrane (TM) 10, which contains the essential anion binding site, and on the neighboring TM9 within the core domain resulted in impaired anion transport activity. We also determined the range of functional impairment in three deafness-associated prestin variants by measuring nonlinear capacitance (NLC), a proxy for motor function. Using the results from our functional analyses, we also evaluated the performance of AlphaMissense (AM), a computational tool for predicting the pathogenicity of missense variants. AM prediction scores correlated well with our experimental results; however, some variants were misclassified, underscoring the necessity of experimentally assessing the effects of variants. Together, our experimental efforts provide invaluable information regarding the pathogenicity of deafness-associated pendrin and prestin variants.
摘要：
Pendrin和Prestin是进化保守的膜蛋白，对正常听力至关重要。这些蛋白质的功能障碍导致人类的听力损失，并且在患者中发现了许多与耳聋相关的pendrin和prestin变体。然而,许多这些变异的致病影响是模棱两可的.这里,我们报告了我们正在进行的使用体外功能测定对pendrin和prestin变体进行实验表征的结果。通过先前建立的荧光阴离子转运测定法，我们确定在包含必需阴离子结合位点的跨膜（TM）10上鉴定出许多pendrin变体，并且在核心域内的相邻TM9上导致阴离子转运活性受损。我们还通过测量非线性电容（NLC）确定了三种与耳聋相关的prestin变体的功能损害范围，运动功能的代理。使用我们功能分析的结果，我们还评估了AlphaMissense(AM)的性能，预测错义变异致病性的计算工具。AM预测分数与我们的实验结果密切相关；然而，一些变体被错误分类，强调实验评估变体效果的必要性。一起,我们的实验工作提供了有关耳聋相关pendrin和prestin变体致病性的宝贵信息.
