Disruption of intraflagellar protein transport in photoreceptor cilia causes Leber congenital amaurosis in humans and mice
Disruption of intraflagellar protein transport in photoreceptor cilia causes Leber congenital amaurosis in humans and mice
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DOI：
10.1172/jci45627
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发表时间：
2011-06-01
影响因子：
15.9
通讯作者：
Ueffing, Marius
中科院分区：
文献类型：
--
作者：
Boldt, Karsten;Mans, Dorus A.;Ueffing, Marius
导致Leber先天性黑蒙（LCA）的突变导致感光细胞在早期死亡，导致儿童失明。为了揭示LCA的分子基础，我们分析了LCA 5中的突变如何在相互作用组水平上影响编码蛋白Lebercilin的连接性。在光感受器中，lebercilin独特地定位于桥接内节和外节的纤毛。使用普遍适用的亲和蛋白质组学方法，我们表明，lebercilin特异性相互作用的鞭毛内运输（IFT）机制在HEK293T细胞。这种相互作用消失时，2人LCA相关的lebercilin突变引入，暗示一个特定的干扰的IFT依赖性蛋白质转运，进化保守的基本机制，发现在所有纤毛。小鼠Lca5的失活导致视蛋白的部分置换和光诱导的arrestin从光感受器外节的移位。这与IFT在连接纤毛处的缺陷一致，导致适当的外节形成失败和随后的感光细胞变性。这些数据表明，lebercilin功能作为一个不可分割的元素，通过感光纤毛的选择性蛋白质运输，并提供了一个分子的证据，破坏IFT可以导致LCA。
The mutations that cause Leber congenital amaurosis (LCA) lead to photoreceptor cell death at an early age, causing childhood blindness. To unravel the molecular basis of LCA, we analyzed how mutations in LCA5 affect the connectivity of the encoded protein lebercilin at the interactome level. In photoreceptors, lebercilin is uniquely localized at the cilium that bridges the inner and outer segments. Using a generally applicable affinity proteomics approach, we showed that lebercilin specifically interacted with the intraflagellar transport (IFT) machinery in HEK293T cells. This interaction disappeared when 2 human LCA-associated lebercilin mutations were introduced, implicating a specific disruption of IFT-dependent protein transport, an evolutionarily conserved basic mechanism found in all cilia. Lca5 inactivation in mice led to partial displacement of opsins and light-induced translocation of arrestin from photoreceptor outer segments. This was consistent with a defect in IFT at the connecting cilium, leading to failure of proper outer segment formation and subsequent photoreceptor degeneration. These data suggest that lebercilin functions as an integral element of selective protein transport through photoreceptor cilia and provide a molecular demonstration that disrupted IFT can lead to LCA.