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

BECERRA, RAQUEL; VOGL, ANNETTE M.; GIUSTI, SEBASTIÁN A.; MERINO, FLORENCIA L.; LINENBERG, IVANA M.; JERÓNIMO LUKIN; BORDENAVE, MARTÍN D.; STEFANI, FERNANDO D.; REFOJO, DAMIÁN

Córdoba

Congreso; XXXIII Congreso de la Sociedad Argentina de Neurociencias; 2018

Sociedad Argentina de Neurociencias

Neuronal development is controlled by signaling cascades regulated by a myriad of posttranslational modifications. Although the role of ubiquitin has been well established in the maturation of nerve cells, the function of other members of the ubiquitin-like protein family remains poorly understood. Nedd8 is the UBL with the highest homology to Ub, and we demonstrated that Neddylation is highly abundant in the brain and is critical for synapse formation and maintenance. Blocking Neddylation with genetic and pharmacological tools reduced 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 cytoskeleton dynamics are involved in the effects of Nedd8 on axodendritic growth. To identify the structural details underlying the effects of Nedd8 we employed live-imaging, superresolution, and fluorescent microscopy. Neddylation blockade with MLN4924 strongly reduced microtubular polymerization, induce ectopic lamellipodia formation and increased the growth cone size in early neurons. In biochemical screenings, we have identified several neddylated targets that are regulators of cytoskeleton structure and function. We evaluated the function of neddylation on those targets performing molecular replacement strategies in primary neuronal cultures and in-utero electroporated mouse brains. The effect of neddylation on dendritic growth and arborization will be discussed.