RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses
Authors
- M.M. Brockmann
- M. Maglione
- C.G. Willmes
- A. Stumpf
- B.A. Bouazza
- L.M. Velasquez
- M.K. Grauel
- P. Beed
- M. Lehmann
- N. Gimber
- J. Schmoranzer
- S.J. Sigrist
- C. Rosenmund
- D. Schmitz
Journal
- eLife
Citation
- eLife 8: e43243
Abstract
All synapses require fusion-competent vesicles and coordinated Ca(2+)-secretion coupling for neurotransmission, yet functional and anatomical properties are diverse across different synapse types. We show that the presynaptic protein RIM-BP2 has diversified functions in neurotransmitter release at different central murine synapses and thus contributes to synaptic diversity. At hippocampal pyramidal CA3-CA1 synapses, RIM-BP2 loss has a mild effect on neurotransmitter release, by only regulating Ca(2+)-secretion coupling. However, at hippocampal mossy fiber synapses, RIM-BP2 has a substantial impact on neurotransmitter release by promoting vesicle docking/priming and vesicular release probability via stabilization of Munc13-1 at the active zone. We suggest that differences in the active zone organization may dictate the role a protein plays in synaptic transmission and that differences in active zone architecture is a major determinant factor in the functional diversity of synapses.