Synapsin I (SYN1)

The synapsin I protein is a member of the synapsin family that are neuronal phosphoproteins which associate with the cytoplasmic surface of synaptic vesicles. Family members are characterized by common protein domains, and they are implicated in synaptogenesis and the modulation of neurotransmitter release, suggesting a potential role in several neuropsychiatric diseases.The phosphoprotein plays a role in regulation of axonogenesis and synaptogenesis.

The protein serves as a substrate for several different protein kinases and phosphorylation may function in the regulation of this protein in the nerve terminal.Synapsin I is found in two isoforms of the protein, Synapsin Ia and Synapsin Ib, with Synapsin Ib being a slightly shorter version of the protein.