Caenorhabditis elegans DYF-2, an orthologue of human WDR19, is a component of the intraflagellar transport machinery in sensory Cilia
MOLECULAR BIOLOGY OF THE CELL
Authors: Efimenko, Evgeni; Blacque, Oliver E.; Ou, Guangshuo; Haycraft, Courtney J.; Yoder, Bradley K.; Scholey, Jonathan M.; Leroux, Michel R.; Swoboda, Peter
Abstract
The intraflagellar transport (IFT) machinery required to build functional cilia consists of a multisubunit complex whose molecular composition, organization, and function are poorly understood. Here, we describe a novel tryptophan-aspartic acid (WD) repeat (WDR) containing IFT protein from Caenorhabditis elegans, DYF-2, that plays a critical role in maintaining the structural and functional integrity of the IFT machinery. We determined the identity of the dyf-2 gene by transgenic rescue of mutant phenotypes and by sequencing of mutant alleles. Loss of DYF-2 function selectively affects the assembly and motility of different IFT components and leads to defects in cilia structure and chemosensation in the nematode. Based on these observations, and the analysis of DYF-2 movement in a Bardet-Biedl syndrome mutant with partially disrupted IFT particles, we conclude that DYF-2 can associate with IFT particle complex B. At the same time, mutations in dyf-2 can interfere with the function of complex A components, suggesting an important role of this protein in the assembly of the IFT particle as a whole. Importantly, the mouse orthologue of DYF-2, WDR19, also localizes to cilia, pointing to an important evolutionarily conserved role for this WDR protein in cilia development and function.
Diversity of renal phenotypes in patients with WDR19 mutations: Two case reports
NEPHROLOGY
Authors: Yoshikawa, Takahisa; Kamei, Koichi; Nagata, Hiroko; Saida, Ken; Sato, Mai; Ogura, Masao; Ito, Shuichi; Miyazaki, Osamu; Urushihara, Maki; Kondo, Shuji; Sugawara, Noriko; Ishizuka, Kiyonobu; Hamasaki, Yuko; Shishido, Seiichiro; Morisada, Naoya; Iijima, Kazumoto; Nagata, Michio; Yoshioka, Takako; Ogata, Kentaro; Ishikura, Kenji
Abstract
WDR19 has been reported as a causative gene of nephronophthisis-related ciliopathies. Patients with WDR19 mutations can show various extrarenal manifestations such as skeletal disorders, Caroli disease, and retinal dystrophy, and typically display nephronophthisis as a renal phenotype. However, there is limited information on the renal phenotypes of patients with WDR19 mutations. We report two Japanese infants with Sensenbrenner syndrome caused by WDR19 mutations who demonstrated different features in renal ultrasound and histopathological results, despite several common extrarenal manifestations. Patient 1 had normal sized and hyperechogenic kidneys with several small cysts and histopathological findings compatible with infantile nephronophthisis. Renal ultrasound of Patient 2 showed enlarged kidneys with diffuse microcysts resembling those of autosomal recessive polycystic kidney disease. Her renal histopathology revealed dysplastic kidney with diffuse glomerular cysts. Genetic testing identified compound heterozygous mutations in WDR19 in both patients (Patient 1: c.953delA, c.3533G>A, Patient 2: c.2645+1G>T, c.3533G>A). Our patients suggest that WDR19 mutations can cause dysplastic kidney in addition to nephronophthisis pathologically. In addition, differences in pathology of the kidneys from WDR19 mutations may result in heterogeneous features in renal ultrasound findings. Renal phenotypes from WDR19 mutations may thus be more diverse than previously reported. Extrarenal manifestations and genetic testing can therefore help to diagnosis this disease more precisely.