Molecular Medicine Unit and Birth Defect Research Centre, Institute of Child Health, University College London (UCL), London WC1N 1EH, UK.
Am J Hum Genet. 2013 Nov 7;93(5):932-44. doi: 10.1016/j.ajhg.2013.10.003. Epub 2013 Oct 31.
Bidirectional (anterograde and retrograde) motor-based intraflagellar transport (IFT) governs cargo transport and delivery processes that are essential for primary cilia growth and maintenance and for hedgehog signaling functions. The IFT dynein-2 motor complex that regulates ciliary retrograde protein transport contains a heavy chain dynein ATPase/motor subunit, DYNC2H1, along with other less well functionally defined subunits. Deficiency of IFT proteins, including DYNC2H1, underlies a spectrum of skeletal ciliopathies. Here, by using exome sequencing and a targeted next-generation sequencing panel, we identified a total of 11 mutations in WDR34 in 9 families with the clinical diagnosis of Jeune syndrome (asphyxiating thoracic dystrophy). WDR34 encodes a WD40 repeat-containing protein orthologous to Chlamydomonas FAP133, a dynein intermediate chain associated with the retrograde intraflagellar transport motor. Three-dimensional protein modeling suggests that the identified mutations all affect residues critical for WDR34 protein-protein interactions. We find that WDR34 concentrates around the centrioles and basal bodies in mammalian cells, also showing axonemal staining. WDR34 coimmunoprecipitates with the dynein-1 light chain DYNLL1 in vitro, and mining of proteomics data suggests that WDR34 could represent a previously unrecognized link between the cytoplasmic dynein-1 and IFT dynein-2 motors. Together, these data show that WDR34 is critical for ciliary functions essential to normal development and survival, most probably as a previously unrecognized component of the mammalian dynein-IFT machinery.
双向（顺行和逆行）鞭毛内运输（IFT）负责货物运输和交付过程，这对于初级纤毛的生长和维持以及 hedgehog 信号功能至关重要。调节纤毛逆行蛋白运输的 IFT 动力蛋白-2 复合物包含一个重链动力蛋白 ATP 酶/动力亚基 DYNC2H1，以及其他功能定义不太明确的亚基。IFT 蛋白（包括 DYNC2H1）的缺乏是一系列骨骼纤毛病的基础。在这里，我们通过使用外显子组测序和靶向下一代测序面板，在 9 个具有 Jeune 综合征（窒息性胸廓发育不良）临床诊断的家族中总共鉴定出 WDR34 的 11 个突变。WDR34 编码一个 WD40 重复蛋白，与衣藻 FAP133 同源，后者是与逆行鞭毛内运输动力相关的动力中间链。三维蛋白建模表明，鉴定出的突变都影响到 WDR34 蛋白-蛋白相互作用的关键残基。我们发现 WDR34 在哺乳动物细胞中集中在中心体和基体周围，也显示轴突染色。WDR34 在体外与动力蛋白-1 轻链 DYNLL1 共免疫沉淀，蛋白质组学数据挖掘表明 WDR34 可能代表细胞质动力蛋白-1 和 IFT 动力蛋白-2 之间以前未被识别的联系。总之，这些数据表明 WDR34 对于纤毛功能至关重要，这些功能对于正常发育和生存至关重要，最有可能是哺乳动物动力蛋白-IFT 机制的一个以前未被识别的组成部分。
