Evolution, structure, and function of the C-terminal domains of Synapsin-IIa

Synapsins are phylogenetically conserved synaptic vesicle (SV)-associated phosphoproteins involved in synapse formation, function, and plasticity. Synapsins have been recently shown to undergo phase transitions regulating the dynamics of the SV reserve pool at the synapse, a process which involves low-complexity regions of these proteins. Here, we investigate the evolution, structure, and functional roles in these processes of the C-terminal domains of a functionally well-characterized synapsin isoform. Using a multidisciplinary approach, with a combination of bioinformatics, biophysics, cellular and molecular approaches, we trace the evolutionary history of these C-terminal synapsin domains and present experimental evidence of their functional roles.