RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses

Brockmann, M. M.; Maglione, M.; Willmes, C. G.; Stumpf, A.; Bouazza, B. A.; Velasquez, L. M.; Grauel, M. K.; Beed, P.; Sigrist, S. J.; Rosenmund, C.; Schmitz, D.

doi:10.1101/469494

bioRxiv · 10.1101/469494

RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses

Brockmann, M. M.·Maglione, M.·Willmes, C. G.·Stumpf, A.·Bouazza, B. A.·Velasquez, L. M.·Grauel, M. K.·Beed, P.·Sigrist, S. J.·Rosenmund, C.·Schmitz, D.

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Abstract

All synapses require fusion-competent vesicles and coordinated Ca2+-secretion coupling for neurotransmission, yet functional and anatomical properties show a high diversity across different synapse types. We show here that the presynaptic protein RIM-BP2 has diversified functions in neurotransmitter release at different central mammalian 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 Ca2+-secretion coupling. However, at hippocampal mossy fiber synapses RIM-BP2 has a strong impact on neurotransmitter release by promoting vesicle docking/priming via recruitment of Munc13-1. In wild type mossy fiber synapses, the distance between RIM-BP2 clusters and Munc13-1 clusters is larger than in hippocampal pyramidal CA3-CA1 synapses, suggesting that spatial 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.

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Brockmann, M. M., Maglione, M., Willmes, C. G., Stumpf, A., Bouazza, B. A., Velasquez, L. M., Grauel, M. K., Beed, P., Sigrist, S. J., Rosenmund, C., Schmitz, D.. 2018-11-13. RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses. https://doi.org/10.1101/469494

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