A family of phosphoproteins associated with synaptic vesicles and that interact with small G proteins such as rab to regulate neurotransmitter release and are phosphorylated by various kinases. They are also implicated in axonogenesis and synaptogenesis. Synapsin Ia (Brain protein 4.1, 705 aa) and Ib are alternatively spliced variants, as are synapsins IIa and IIb (582 aa). A third synapsin ( synapsin III, 580 aa) has a more restricted distribution. Mutations in synapsin I may be associated with X-linked disorders with primary neuronal degeneration such as Rett's syndrome.
Subjects: Medicine and Health — Chemistry.