May be involved in neuronal plasticity. Highly expressed in the brain. Phosphorylated. Phosphorylation by G-protein coupled receptor kinases (GRK) is more efficient than phosphorylation by CK1, CK2 and CaM-kinase II (By similarity). Simultaneous knockout of SNCA, SNCB and SNCG exhibit an age-dependent decrease in SNARE-complex assembly. Thus, synucleins are required for maintaining normal SNARE-complex assembly during aging in mice. Belongs to the synuclein family.