The ins and outs of IgE-dependent mast-cell exocytosis

Mast cells (MCs) are able to secrete the contents of preformed cytoplasmic secretory granules (SGs) on encountering certain stimulants. For MCs, this process is fundamental to their role in innate and acquired immunity. Immunological adaptation through the production of IgE antibodies, to normally innocuous substances, has kidnapped the MC exocytotic response to cause allergic disease. Thus' understanding the molecular events in IgE-dependent MC exocytosis holds promise for therapeutic intervention. Recent advances, in deciphering the coupling of the high affinity IgE receptor (FcepsilonRI) to the secretory machinery, promote a new paradigm of the molecular coordination of MC exocytosis. A clearer picture of the link between FcepsilonRI stimulation and SG exocytosis is emerging.