Clarinet, a novel C. elegans active zone protein with homology to vertebrate Piccolo and Rim, uses its different isoforms for diverse functions, including synaptic vesicle clustering, vesicle release and synaptogenesis.
The mobilization or silencing of two heterogeneous pools of synaptic vesicles via different frequencies probably enables granule cell to Purkinje cell synapses to better discriminate between the high-rate code of sensory information and background noise.
In mammals, the vesicular glutamate transporter 1 acquired a proline-rich sequence that negatively regulates the spontaneous release of glutamate by reducing the exchange of synaptic vesicles along the axon.
Parallel measurements of pH gradient and membrane potential at the single vesicle level have revealed that the synaptic vesicle acidification is initiated by removal of its clathrin coat, which blocks vesicular ATPase activity.
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.
Building on previous work (Diao et al., 2012), we show that the mechanism by which complexin suppresses spontaneous fusion is distinct from the mechanism by which it synchronizes Ca2+-triggered fusion.