Rezi Csenge K, Aslanyan Mariam G, Diwan Gaurav D, Cheng Tao, Chamlali Mohamed, Junger Katrin, Anvarian Zeinab, Lorentzen Esben, Pauly Kleo B, Afshar-Bahadori Yasmin, Fernandes Eduardo F A, Qian Feng, Tosi Sébastien, Christensen Søren T, Pedersen Stine F, Strømgaard Kristian, Russell Robert B, Miner Jeffrey H, Mahjoub Moe R, Boldt Karsten, Roepman Ronald, Pedersen Lotte B
Department of Biology, University of Copenhagen, Denmark.
Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands.
bioRxiv. 2024 Mar 14:2023.11.10.566524. doi: 10.1101/2023.11.10.566524.
Polarized vesicular trafficking directs specific receptors and ion channels to cilia, but the underlying mechanisms are poorly understood. Here we describe a role for DLG1, a core component of the Scribble polarity complex, in regulating ciliary protein trafficking in kidney epithelial cells. Conditional knockout of in mouse kidney caused ciliary elongation and cystogenesis, and cell-based proximity labelling proteomics and fluorescence microscopy showed alterations in the ciliary proteome upon loss of DLG1. Specifically, the retromer-associated protein SDCCAG3, IFT20 and polycystin-2 (PC2) were reduced in cilia of DLG1 deficient cells compared to control cells. This phenotype was recapitulated and rescuable by re-expression of wildtype DLG1, but not a Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)-associated DLG1 variant, p.T489R. Finally, biochemical approaches and Alpha Fold modelling suggested that SDCCAG3 and IFT20 form a complex that associates, at least indirectly, with DLG1. Our work identifies a key role for DLG1 in regulating ciliary protein composition and suggests that ciliary dysfunction of the p.T489R DLG1 variant may contribute to CAKUT.
极化囊泡运输将特定受体和离子通道导向纤毛，但其潜在机制尚不清楚。在这里，我们描述了Scribble极性复合体的核心成分DLG1在调节肾上皮细胞纤毛蛋白运输中的作用。在小鼠肾脏中条件性敲除DLG1会导致纤毛伸长和囊肿形成，基于细胞的邻近标记蛋白质组学和荧光显微镜显示，DLG1缺失后纤毛蛋白质组发生改变。具体而言，与对照细胞相比，DLG1缺陷细胞的纤毛中与回收蛋白相关的SDCCAG3、IFT20和多囊蛋白-2（PC2）减少。通过野生型DLG1的重新表达可以重现并挽救这种表型，但先天性肾脏和尿路异常（CAKUT）相关的DLG1变体p.T489R则不能。最后，生化方法和Alpha Fold建模表明，SDCCAG3和IFT20形成一个复合体，至少间接与DLG1相关。我们的工作确定了DLG1在调节纤毛蛋白组成中的关键作用，并表明p.T489R DLG1变体的纤毛功能障碍可能导致CAKUT。
