Neddylation orchestrates the complex transcriptional and post-transcriptional program that drives axonal myelination
Myelination is essential for neuronal function and health. In peripheral nerves, >100 causative mutations have been identified that cause Charcot-Marie-Tooth disease, a disorder that can affect myelin sheaths. Among these, a number of mutations are related to essential targets of the post-translation modification neddylation, although how these lead to myelin defects is unclear. Here, we demonstrate that inhibiting neddylation leads to a striking absence of peripheral myelin and axonal loss both in developing and regenerating mouse nerves. Importantly, our data indicate that neddylation exerts a global influence on the complex transcriptional and post-transcriptional program by simultaneously regulating the expression and function of multiple essential myelination signals, including the master transcription factor EGR2 and the negative regulators c-Jun and Sox2, and inducing global secondary changes in downstream pathways, including the mTOR and YAP/TAZ signalling pathways. This places neddylation as a critical regulator of myelination and delineates the potential pathogenic mechanisms involved in CMT mutations related to neddylation. Overall design: RNA was isolated from 7 days old mice sciatic nerves from WT (n=4) and Nae1 cKO mice (n=4). Total RNA was treated with DNAse I (Invitrogen) for 30 min at 37 ºC. Then the samples were cleaned with Genejet RNA cleanup and Concentration kit (Thermo Scientific) (the columns were eluted with 20-30µl ultra-pure water), and samples processed for RNA sequencing.