Myristoylated alanine-rich C kinase substrate, but not Ca2+/calmodulin-dependent protein kinase II, is the mediator in cortical granules exocytosis.

Sperm-egg fusion induces cortical granules exocytosis (CGE), a process that ensures the block to polyspermy. CGE can be induced independently by either a rise in intracellular calcium concentration or protein kinase C (PKC) activation. We have previously shown that myristoylated alanine-rich C kinase substrate (MARCKS) cross-links filamentous actin (F-actin) and regulates its reorganization.