Both enlargosomes (red) and classical secretory vesicles (green) carry out regulated exocytosis.
Meldolesi
Various signals elicit exocytosis. The best-studied example is regulated secretion, in which a specific cargo is delivered outside the cell. But regulated exocytosis can occur in nonsecretory cells, begging the question of which organelle in these cells responds to the stimulus. Recently, lysosomes were shown to fuse to the PM in response to damage-induced calcium signals, but they no longer appear to be the only organelle in the arsenal.
By comparing the PM of living cells before and after stimulation, Meldolesi's group has now identified desmoyokin (dA), a marker for regulated exocytosis that appears on the PM in response to increases in intracellular calcium. dA was found in a set of small...
