Mutations in TRAF3IP1/IFT54 reveal a new role for IFT proteins in microtubule stabilization
- Nat Commun. 2015 Oct 21;6:8666. doi: 10.1038/ncomms9666.
- 1. Inserm UMR-1163, Laboratory of Hereditary Kidney Diseases, 75015 Paris, France.
- 2. Paris Descartes Sorbonne Paris Cité University, Imagine Institute, 75015 Paris, France.
- 3. Novartis Institutes for Biomedical Research, Basel CH-4002, Switzerland.
- 4. Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, 82152 Martinsried, Germany.
- 5. Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
- 6. Division of Nephrology, Department of Internal Medicine, University Clinic Leipzig, 04103 Leipzig, Germany.
- 7. Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, USA.
- 8. Inserm UMR-1163, Genomic Core Facility, 75015 Paris, France.
- 9. Paris Descartes Sorbonne Paris Cité University, Bioinformatics Core Facility, 75015 Paris, France.
- 10. Cell Imaging Platform, INSERM US24 Structure Fédérative de recherche Necker, Paris Descartes Sorbonne Paris Cité University, 75015 Paris, France.
- 11. Department of Medical Genetic, Arnaud de Villeneuve University Health Center, 34090 Montpellier, France.
- 12. Nephrology department, L'Archet II Hospital, Nice University Health Center, 06202 Nice, France.
- 13. Hemodialysis-Nephrology Department, William Morey Hospital, 71321 Chalon-sur-Saône, France.
- 14. Department of Pediatrics, Center of Pediatric Nephrology and Transplantation, Cairo University, Egyptian Group for Orphan Renal Diseases, 11956 Cairo, Egypt.
- 15. INSERM U968, CNRS UMR 7210; Sorbonne Universités, Université Pierre et Marie Curie, UMR S968, Institut de la vision, 75012 Paris, France.
- 16. Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM, Direction de l'Hospitalisation et de l'Organisation des Soins, Centre d'Investigation Clinique 1423, 75012 Paris, France.
- 17. Assistance Publique-Hôpitaux de Paris, Pediatric Nephrologic department, Necker-Enfants Malades Hospital, 75015 Paris, France.
- 18. Nephrology Division, Massachusetts General Hospital, Charlestown, Massachusetts 02114, USA.
- 19. Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114, USA.
- 20. Assistance Publique-Hôpitaux de Paris, Department of Genetics, Necker-Enfants Malades Hospital, 75015 Paris, France.
Ciliopathies are a large group of clinically and genetically heterogeneous disorders caused by defects in primary cilia. Here we identified mutations in TRAF3IP1 (TNF Receptor-Associated Factor Interacting Protein 1) in eight patients from five families with nephronophthisis (NPH) and retinal degeneration, two of the most common manifestations of ciliopathies. TRAF3IP1 encodes IFT54, a subunit of the IFT-B complex required for ciliogenesis. The identified mutations result in mild ciliary defects in patients but also reveal an unexpected role of IFT54 as a negative regulator of microtubule stability via MAP4 (microtubule-associated protein 4). Microtubule defects are associated with altered epithelialization/polarity in renal cells and with pronephric cysts and microphthalmia in zebrafish embryos. Our findings highlight the regulation of cytoplasmic microtubule dynamics as a role of the IFT54 protein beyond the cilium, contributing to the development of NPH-related ciliopathies.