The Nedd8 pathway regulates axo-dendritic development by controlling cytoskeletal dynamics

BECERRA, RAQUEL; VOGL, ANNETTE; GIUSTI, SEBASTIAN; LINENBERG, IVANA; REFOJO, DAMIAN

Cordoba

Congreso; XXXIII Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias; 2018

Sociedad Argentina de Investigación en Neurociencias

Neuronal development is controlled by signaling cascades regulated by a myriad ofposttranslational modifications. Although the role of ubiquitin has been well established in thematuration of nerve cells, the function of other members of the ubiquitin-like protein familyremains poorly understood. Nedd8 is the UBL with the highest homology to Ub, and wedemonstrated that Neddylation is highly abundant in the brain and is critical for synapseformation and maintenance. Blocking Neddylation with genetic and pharmacological toolsreduced axonal and dendritic growth both in cell culture and in-utero electroporation approaches.These effects were partially reverted by Cyto-D and Taxol. These results suggest that cytoskeletondynamics are involved in the effects of Nedd8 on axodendritic growth. To identify the structuraldetails underlying the effects of Nedd8 we employed live-imaging, superresolution, andfluorescent microscopy. Neddylation blockade with MLN-4924 strongly reduced microtubularpolymerization, induce ectopic lamellipodia formation and increased the growth cone size in earlyneurons. In biochemical screenings, we have identified several neddylated targets that areregulators of cytoskeleton structure and function. We evaluated the function of neddylation onthose targets performing molecular replacement strategies in primary neuronal cultures and inutero electroporated mouse brains. The effect of neddylation on dendritic growth andarborization will be discusses.