The synapsins are a family of neuron-specific phosphoproteins that coatsynaptic vesicles and are involved in the binding between these vesiclesand the cytoskeleton (including actin filaments). The family comprises 5homologous proteins 1a, 1b, 2a, 2b and 3. Synapsins 1, 2, and 3 areencoded by 3 different genes. The a and b isoforms of synapsin 1 and 2 aresplice variants of the primary transcripts [].This entry represents synapsin-2 (SYN2) and synapsin-3 (SYN3). SYN2 is thought to be involved in noradrenaline secretion by sympathetic neurons []. SYN3 is expressed in cells of the subgranular layer of the hippocampal dentate gyrus []. It may function in neurogenesis and synaptic plasticity []. Unlike SYN1 and SYN2, deletion of SYN3 does not cause seizures or an apparent neurological phenotype and has relatively subtle effects on neurotransmission [].
