Synaptotagmin is widely regarded as the primary calcium sensor for synaptic vesicle exocytosis (Fernandez-Chacon et al., 2001; Wang et al., 2003). Moreover recent studies indicate that the protein also plays a key role in endocytosis (Poskanzer et al., 2003). Synaptotagmin can be phosphorylated by multiple protein kinases and this may play a key role in modulation of synaptotagmin ability to influence both the exocytotic and endocytotic components of synaptic transmission (Hilfiker et al., 1999; Lee et al., 2004).