Information about Exocytosis

In eukaryotes there are two types of exocytosis: 1) Ca2+ triggered non-constitutive (i. e. , regulated exocytosis) and 2) non-Ca2+ triggered constitutive (i. e. , non-regulated). Ca2+ triggered non-constitutive exocytosis requires an external signal, a specific sorting signal on the vesicles, a clathrin coat, as well as an increase in intracellular calcium. Exocytosis in neuronal chemical synapses is Ca2+ triggered and serves interneuronal signalling. Constitutive exocytosis is performed by all cells and serves the release of components of the extracellular matrix or delivery of newly synthesized membrane proteins that are incorporated in the plasma membrane after the fusion of the transport vesicle.