I've been doing a bit of reading about mast cell degranulation and have become thoroughly lost while trying to understand how the secretory granules are actually secreted.
I understand that there are many ways in which mast cells can be stimulated to degranulate, but I have been focusing on the example of IgE bound to FcεRI receptors. I believe I'm right in saying that antigen binding causes cross-linking of FcεRI receptors (since the antigen epitopes bind with the IgE paratopes and the IgE antibodies are themselves bound to the FcεRI receptors.) This recruits Lyn which phosphorylates ITAM motifs on the β and γ chains of the FcεRI receptors. This recruits Syk which is phosphorylated and activates LAT. This phosphorylates PLCγ which catalyzes the breakdown of PIP2 into IP3 and DAG.
All of this leads to the activation of PKC. I understand that PKC is (at least in part) responsible for the exoctyosis of SG but my question is by what means? Wikipedia, KEGG and this handy resource are all very cursory, whereas the academic papers which google turns up are way over my head.
So, if I might, what is it that PKC does and, in general, how are the secretory granules transferred from within the cell to the plasma membrane and out into the environment around the cell?