Wilson disease missense mutations in ATP7B affect metal-binding domain structural dynamics
Wilson disease missense mutations in ATP7B affect metal-binding domain structural dynamics
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DOI：
10.1007/s10534-019-00219-y
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发表时间：
2019-12-01
期刊：
影响因子：
3.5
通讯作者：
Wittung-Stafshede, Pernilla
中科院分区：
文献类型：
--
作者：
Shanmugavel, Kumaravel Ponnandai;Kumar, Ranjeet;Wittung-Stafshede, Pernilla
威尔逊病（WD）是由ATP7B基因突变引起的，ATP7B是一种调节细胞中铜水平的铜转运蛋白。大量误义突变已被报道可导致WD，但基因型-表型相关性尚未建立。由于WD的遗传筛查可能在未来成为现实，因此了解个体突变如何影响ATP7B功能是很重要的，最终目的是预测疾病的病理生理。为了开始评估功能障碍的机制，我们研究了ATP7B金属结合结构域5和6中的四种可能引起wd的错义突变。在传统的酵母实验中，四种变体中的三种显示ATP7B铜转运能力降低。为了在原子水平上探测突变引起的结构动力学效应，采用分子动力学模拟（每个变异模拟时间为1.5 μ s）。通过比较有和没有突变的单个金属结合域，我们通过均方根波动和二级结构含量分析确定了结构动力学的明显差异。大多数突变引入了远程效应，导致铜结合环的动力学增加。综上所述，突变引起的结构动力学的长期改变为铜转运能力降低提供了基本原理。
Wilson disease (WD) is caused by mutations in the gene for ATP7B, a copper transport protein that regulates copper levels in cells. A large number of missense mutations have been reported to cause WD but genotype-phenotype correlations are not yet established. Since genetic screening for WD may become reality in the future, it is important to know how individual mutations affect ATP7B function, with the ultimate goal to predict pathophysiology of the disease. To begin to assess mechanisms of dysfunction, we investigated four proposed WD-causing missense mutations in metal-binding domains 5 and 6 of ATP7B. Three of the four variants showed reduced ATP7B copper transport ability in a traditional yeast assay. To probe mutation-induced structural dynamic effects at the atomic level, molecular dynamics simulations (1.5 mu s simulation time for each variant) were employed. Upon comparing individual metal-binding domains with and without mutations, we identified distinct differences in structural dynamics via root-mean square fluctuation and secondary structure content analyses. Most mutations introduced distant effects resulting in increased dynamics in the copper-binding loop. Taken together, mutation-induced long-range alterations in structural dynamics provide a rationale for reduced copper transport ability.