Complexin facilitates exocytosis and synchronizes vesicle release in two secretory model systems

摘要: Complexins (Cplxs) are small, SNARE-associated proteins believed to regulate fast, calcium-triggered exocytosis. However, studies have pointed either an inhibitory and/or facilitatory role in exocytosis, and the of Cplxs synchronizing exocytosis is relatively unexplored. Here, we compare function two types complexin, Cplx 1 2, model systems calcium-dependent In mouse neuromuscular junctions (NMJs), find that lack significantly reduces desynchronizes synaptic transmission; furthermore, high-frequency stimulation elicits facilitation, instead normal depression, degree facilitation highly sensitive amount cytoplasmic calcium buffering. 2-null adrenal chromaffin cells, also decreased desynchronized evoked release, identify a significant reduction vesicle pool close channels (immediately releasable pool, IRP). Viral transduction with or 2 rescues both size response synchronicity it restores IRP size. Our findings mutually compatible indicate facilitating priming, lead new hypothesis may synchronize release by promoting coupling between secretory vesicles channels.