Syntaxin 4 regulates retrograde signaling in the postsynaptic compartment at Drosophila synapses by controlling trafficking of Neuroligin and Synaptotagmin 4 cargo.

Ca²⁺-free synaptotagmin-1 binds to neuronal SNARE complexes anchored on nanodiscs, and Ca²⁺ releases this interaction to induce tight, specific binding to PIP₂-containing membranes.

An unbiased separation method reveals distinct subpopulations of insulin secretory vesicles that undergo dynamic remodeling upon glucose stimulation.

Drosophila synaptotagmin 7 functions to restrict SV availability and release, but does not act as the Ca²⁺ sensor mediating the asynchronous release and facilitation remaining in synaptotagmin 1 mutants.

HID-1 is a novel player mediating homotypic fusion of immature secretory granules.

Two acidic membrane lipids increase synaptotagmin-1 dwell time and penetration into the membrane, reducing the membrane dissociation of synaptotagmin-1.

Complexin, in conjunction with Synaptotagmin, clamps the SNARE-assembly process under resting conditions and promote vesicle fusion in response to calcium signal.

Synaptotagmin-7 acts synergistically with synaptotagmin-1 by placing vesicles close to the plasma membrane within reach of the SNARE/Munc13-complex, supporting their priming and setting the stage for fast and slow fusion.

A few SNARE complexes suffice to fuse membranes, but many more are needed to dilate the nascent fusion pore by molecular crowding for efficient neurotransmitter or hormone release during exocytosis.

A mathematical model of neurotransmitter release predicts that a mutual stabilization of calcium and membrane phospholipids binding to synaptotagmin proteins allows several synaptotagmins to work together for fast synaptic transmission.