[en] Neurodevelopmental disorders with periventricular nodular heterotopia (PNH) are etiologically heterogeneous, and their genetic causes remain in many cases unknown. Here we show that missense mutations in NEDD4L mapping to the HECT domain of the encoded E3 ubiquitin ligase lead to PNH associated with toe syndactyly, cleft palate and neurodevelopmental delay. Cellular and expression data showed sensitivity of PNH-associated mutants to proteasome degradation. Moreover, an in utero electroporation approach showed that PNH-related mutants and excess wild-type NEDD4L affect neurogenesis, neuronal positioning and terminal translocation. Further investigations, including rapamycin-based experiments, found differential deregulation of pathways involved. Excess wild-type NEDD4L leads to disruption of Dab1 and mTORC1 pathways, while PNH-related mutations are associated with deregulation of mTORC1 and AKT activities. Altogether, these data provide insights into the critical role of NEDD4L in the regulation of mTOR pathways and their contributions in cortical development.
Caviness, V.S. Jr., Takahashi, T. & Nowakowski, R.S. Numbers, time and neocortical neuronogenesis: a general developmental and evolutionary model. Trends Neurosci. 18, 379-383 (1995).
Rakic, P. & Caviness, V.S. Jr. Cortical development: view from neurological mutants two decades later. Neuron 14, 1101-1104 (1995).
Barkovich, A.J., Guerrini, R., Kuzniecky, R.I., Jackson, G.D. & Dobyns, W.B. A developmental and genetic classifcation for malformations of cortical development: update 2012. Brain 135, 1348-1369 (2012).
Francis, F. et al. Human disorders of cortical development: from past to present. Eur. J. Neurosci. 23, 877-893 (2006).
Guerrini, R. & Dobyns, W.B. Malformations of cortical development: clinical features and genetic causes. Lancet Neurol. 13, 710-726 (2014).
Fox, J.W. et al. Mutations in flamin 1 prevent migration of cerebral cortical neurons in human periventricular heterotopia. Neuron 21, 1315-1325 (1998).
Parrini, E. et al. Periventricular heterotopia: phenotypic heterogeneity and correlation with flamin A mutations. Brain 129, 1892-1906 (2006).
Ferland, R.J. et al. Disruption of neural progenitors along the ventricular and subventricular zones in periventricular heterotopia. Hum. Mol. Genet. 18, 497-516 (2009).
Carabalona, A. et al. A glial origin for periventricular nodular heterotopia caused by impaired expression of flamin-A. Hum. Mol. Genet. 21, 1004-1017 (2012).
Lian, G. et al. Filamin A regulates neural progenitor proliferation and cortical size through Wee1-dependent Cdk1 phosphorylation. J. Neurosci. 32, 7672-7684 (2012).
Sheen, V.L. et al. Mutations in ARFGEF2 implicate vesicle traffcking in neural progenitor proliferation and migration in the human cerebral cortex. Nat. Genet. 36, 69-76 (2004).
Conti, V. et al. Periventricular heterotopia in 6q terminal deletion syndrome: role of the C6orf70 gene. Brain 136, 3378-3394 (2013).
Poirier, K. et al. Mutations in TUBG1, DYNC1H1, KIF5C and KIF2A cause malformations of cortical development and microcephaly. Nat. Genet. 45, 639-647 (2013).
Mirzaa, G.M. et al. Characterisation of mutations of the phosphoinositide-3-kinase regulatory subunit, PIK3R2, in perisylvian polymicrogyria: a next-generation sequencing study. Lancet Neurol. 14, 1182-1195 (2015).
Kumar, S., Tomooka, Y. & Noda, M. Identifcation of a set of genes with developmentally down-regulated expression in the mouse brain. Biochem. Biophys. Res. Commun. 185, 1155-1161 (1992).
Sudol, M., Chen, H.I., Bougeret, C., Einbond, A. & Bork, P. Characterization of a novel protein-binding module-the WW domain. FEBS Lett. 369, 67-71 (1995).
Rizo, J. & Südhof, T.C. C2-domains, structure and function of a universal Ca2+-binding domain. J. Biol. Chem. 273, 15879-15882 (1998).
Huang, L. et al. Structure of an E6AP-UbcH7 complex: insights into ubiquitination by the E2-E3 enzyme cascade. Science 286, 1321-1326 (1999).
Goel, P., Manning, J.A. & Kumar, S. NEDD4-2 (NEDD4L): the ubiquitin ligase for multiple membrane proteins. Gene 557, 1-10 (2015).
Garrone, N.F., Blazer-Yost, B.L., Weiss, R.B., Lalouel, J.M. & Rohrwasser, A. A human polymorphism affects NEDD4L subcellular targeting by leading to two isoforms that contain or lack a C2 domain. BMC Cell Biol. 10, 26 (2009).
Hsia, H.E. et al. Ubiquitin E3 ligase Nedd4-1 acts as a downstream target of PI3K/PTEN-mTORC1 signaling to promote neurite growth. Proc. Natl. Acad. Sci. USA 111, 13205-13210 (2014).
Franco, S.J., Martinez-Garay, I., Gil-Sanz, C., Harkins-Perry, S.R. & Müller, U. Reelin regulates cadherin function via Dab1/Rap1 to control neuronal migration and lamination in the neocortex. Neuron 69, 482-497 (2011).
Olson, E.C., Kim, S. & Walsh, C.A. Impaired neuronal positioning and dendritogenesis in the neocortex after cell-autonomous Dab1 suppression. J. Neurosci. 26, 1767-1775 (2006).
Sekine, K., Honda, T., Kawauchi, T., Kubo, K. & Nakajima, K. The outermost region of the developing cortical plate is crucial for both the switch of the radial migration mode and the Dab1-dependent "inside-out" lamination in the neocortex. J. Neurosci. 31, 9426-9439 (2011).
Sekine, K. et al. Reelin controls neuronal positioning by promoting cell-matrix adhesion via inside-out activation of integrin α5β1. Neuron 76, 353-369 (2012).
Lifton, R.P., Gharavi, A.G. & Geller, D.S. Molecular mechanisms of human hypertension. Cell 104, 545-556 (2001).
Boase, N.A. & Kumar, S. NEDD4: the founding member of a family of ubiquitin- protein ligases. Gene 557, 113-122 (2015).
Moon, U.Y. et al. Impaired reelin-Dab1 signaling contributes to neuronal migration defcits of tuberous sclerosis complex. Cell Rep. 12, 965-978 (2015).
Gao, S. et al. Ubiquitin ligase Nedd4L targets activated Smad2/3 to limit TGF-β signaling. Mol. Cell 36, 457-468 (2009).
Yu, J.S. et al. PI3K/mTORC2 regulates TGF-β/activin signalling by modulating Smad2/3 activity via linker phosphorylation. Nat. Commun. 6, 7212 (2015).
Wiesner, S. et al. Autoinhibition of the HECT-type ubiquitin ligase Smurf2 through its C2 domain. Cell 130, 651-662 (2007).
Bruce, M.C. et al. Regulation of Nedd4-2 self-ubiquitination and stability by a PY motif located within its HECT-domain. Biochem. J. 415, 155-163 (2008).
Wang, J. et al. Calcium activates Nedd4 E3 ubiquitin ligases by releasing the C2 domain-mediated auto-inhibition. J. Biol. Chem. 285, 12279-12288 (2010).
Escobedo, A. et al. Structural basis of the activation and degradation mechanisms of the E3 ubiquitin ligase Nedd4L. Structure 22, 1446-1457 (2014).
Honda, T. & Nakajima, K. Proper level of cytosolic disabled-1, which is regulated by dual nuclear translocation pathways, is important for cortical neuronal migration. Cereb. Cortex 26, 3219-3236 (2016).
Rivière, J.B. et al. De novo germline and postzygotic mutations in AKT3, PIK3R2 and PIK3CA cause a spectrum of related megalencephaly syndromes. Nat. Genet. 44, 934-940 (2012).
Jansen, L.A. et al. PI3K/AKT pathway mutations cause a spectrum of brain malformations from megalencephaly to focal cortical dysplasia. Brain 138, 1613-1628 (2015).
Wright, C.F. et al. Genetic diagnosis of developmental disorders in the DDD study: a scalable analysis of genome-wide research data. Lancet 385, 1305-1314 (2015).
Cau, E., Gradwohl, G., Fode, C. & Guillemot, F. Mash1 activates a cascade of bHLH regulators in olfactory neuron progenitors. Development 124, 1611-1621 (1997).
Kielar, M. et al. Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human. Nat. Neurosci. 17, 923-933 (2014).
