Synapsin I plays a key role in synaptic plasticity in brain (Feng et al., 2002; Nayak et
al., 1996). This effect is due in large part to the ability of the synapsins to regulate the availability of
synaptic vesicles for release. Th
e role of synapsin in synaptic plasticity and in synaptogensis is
regulated by phosphorylation (Jovanovic et al., 2001; Kao et al., 2002). Serine 603 is the site on
synapsin I that is phosphorylated by calcium calmodulin kinase II and by p21-activated kinases
(Sakurada et al., 2002; Czernik et al., 1987). Phosphorylation of this site is thought to regulate
synaptic vesicle function (Nayak et al., 1996; Bahler and Greengard, 1987; McGuinness et al.,
1989).
