Synaptojanin-1 Antibody #80377

Synaptojanin-1 is a nerve terminal-enriched phosphatase that dephosphorylates phosphoinositides (1-3). Synaptojanin-1 contains an N-terminal Sac1 PI4P phosphatase domain (Sac domain) that dephosphorylates PI3P and PI(3,5)P2, a central 5-phosphatase domain that dephosphorylates PI(4,5)P2 and PI(3,4,5)P3, and an RNA recognition motif (4). In the brain, synaptic vesicles are released in response to action potentials, releasing neurotransmitters from synaptic vesicles and initiating interneuronal communication. As part of the synaptic vesicle cycle, fused synaptic vesicle membranes and proteins are endocytosed to be recycled to generate new synaptic vesicles in order to maintain neuronal function. A complex set of proteins, enriched in synaptic vesicles and synaptic membrane, via interaction with highly regulated lipid compositions at the synapse, dynamically regulate the synaptic vesicle cycling process (5). As part of that machinery, Synaptojanin-1 initiates completion of synaptic vesicle endocytosis by regulating, with its partner endophilin-A, the removal of clathrin and the formation of the vesicle “neck” (6). The dephosphorylation of PI(4,5)P2 at the synaptic membrane by Synaptojanin-1 phosphatase activity is critical in shedding endocytic factors from their membranes (4,7).  Recently, several genetic studies have linked proteins that participate in synaptic vesicle endocytic recycling, including Synaptojanin-1, to early onset Parkinson's disease (4).