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ligand binds its membrane G-linked protein receptor

activation of a G protein: Gq

Gq activates a phospholipase C (called C beta)

generates both IP3 and diacylglycerol (DAG)

IP3 diffuses thro the cytosol

IP3 binds to IP3 receptor channel (ligand-gated calcium channel)

Calcium is released into cytosol

Calcium & DAG activate members of the protein kinase C (PKC) family

PKC phosphorylates ser & thr on a variety of target proteins

DAG remains in membrane where it activates protein kinase C

displacement of GDP by GTP & dissociation of sub-units

GTP-G aplha complex binds to phospholipase C and activates it

PIP2 cleaved

DAG & IP3 signaling