Proteolytic events are relevant cellular responses during nervous system regeneration of the starfish Marthasterias glacialis

The molecular pathways that trigger the amazing intrinsic regenerative ability of echinoderm nervous system are still unknown. In order to approach this subject, a 2D-DIGE proteomic strategy was used, to screen proteome changes during neuronal regeneration in vivo, using starfish (Asteroidea, Echinodermata) as a model. A total of 528 proteins showed significant variations during radial nerve cord regeneration in both soluble and membrane protein-enriched fractions. Several functional classes of proteins known to be involved in axon regeneration events in other model organisms, such as chordates, were identified for the first time in the regenerating echinoderm nervous system. Unexpectedly, most of the identified proteins presented a molecular mass either higher or lower than expected. Such results suggest a functional modulation through protein post-translational modifications, such as proteolysis. Among these are proteins involved in cytoskeleton and microtubule regulators, axon guidance molecules and growth cone modulators, protein de novo synthesis machinery, RNA binding and transport, transcription factors, kinases, lipid signaling effectors and proteins with neuroprotective functions. In summary, the impact of proteolysis during regeneration events is here shown, although requiring further studies to detail on the mechanisms involving this post-transcriptional event on nervous system regeneration.