title: Control of the Wnt pathways by nephrocystin-4 is required for morphogenesis of the zebrafish pronephros.
abstract: Nephronophthisis is a hereditary nephropathy characterized by interstitial fibrosis and cyst formation. It is caused by mutations in NPHP genes encoding the ciliary proteins, nephrocystins. In this paper, we investigate the function of nephrocystin-4, the product of the nphp4 gene, in vivo by morpholino-mediated knockdown in zebrafish and in vitro in mammalian kidney cells. Depletion of nephrocystin-4 results in convergence and extension defects, impaired laterality, retinal anomalies and pronephric cysts associated with alterations in early cloacal morphogenesis. These defects are accompanied by abnormal ciliogenesis in the cloaca and in the laterality organ. We show that nephrocystin-4 is required for the elongation of the caudal pronephric primordium and for the regulation of cell rearrangements during cloaca morphogenesis. Moreover, depletion of either inversin, the product of the nphp2 gene, or of the Wnt-planar cell polarity (PCP) pathway component prickle2 increases the proportion of cyst formation in nphp4-depleted embryos. Nephrocystin-4 represses the Wnt-β-catenin pathway in the zebrafish cloaca and in mammalian kidney cells in culture. In these cells, nephrocystin-4 interacts with inversin and dishevelled, and regulates dishevelled stability and subcellular localization. Our data point to a function of nephrocystin-4 in a tight regulation of the Wnt-β-catenin and Wnt-PCP pathways, in particular during morphogenesis of the zebrafish pronephros. Moreover, they highlight common signalling functions for inversin and nephrocystin-4, suggesting that these two nephrocystins are involved in common physiopathological mechanisms.
authors.affiliation: INSERM U983, Tour Lavoisier, Hôpital Necker-Enfants Malades, 149 rue de Sèvres, Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Burcklé
authors.forename: Helori-Mael
authors.initials: HM
authors.lastname: Gaudé
authors.forename: Christine
authors.initials: C
authors.lastname: Vesque
authors.forename: Flora
authors.initials: F
authors.lastname: Silbermann
authors.forename: Rémi
authors.initials: R
authors.lastname: Salomon
authors.forename: Cécile
authors.initials: C
authors.lastname: Jeanpierre
authors.forename: Corinne
authors.initials: C
authors.lastname: Antignac
authors.forename: Sophie
authors.initials: S
authors.lastname: Saunier
authors.forename: Sylvie
authors.initials: S
authors.lastname: Schneider-Maunoury
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis / Q000235:genetics; D002460:Cell Line; D002923:Cilia / Q000235:genetics / Q000473:pathology; D000072261:Dishevelled Proteins; D004285:Dogs; D057809:HEK293 Cells; D006801:Humans; D008938:Mitosis / Q000235:genetics; D009024:Morphogenesis / Q000235:genetics*; D010641:Phenotype; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D055550:Protein Stability; D021381:Protein Transport / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics*; D051153:Wnt Proteins / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000072261:Dishevelled Proteins; D010750:Phosphoproteins; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D051176:beta Catenin; C561793:nephrocystin-4, zebrafish