Figure 3. The action modes of PLCζ and Ca²⁺ release from ER stores.

Either XY linker or EF hand domain of PLCζ binds with the intracellular vesicular PI(4,5)P2 due to their positive charges. PI(4,5)P2 was then hydrolyzed to IP3 and DAG. As the ER membrane channel, IP3R1 mediated the Ca²⁺ flowing out from ER after binding with IP3. During this import process, M-phase kinases phosphorylated IP3R1 and promoted Ca²⁺ efflux.