The Downstream Regulation of Chemokine Receptor Signalling: Implications for Atherosclerosis

Figure 3

RGS proteins in chemokine-mediated GPCR signalling. Following receptor activation and G-protein coupling, the Gα and Gβ γ subunits dissociate (1) and regulate downstream effector functions such as activation of PLC (2) and inhibition of adenyl cyclase (3). The β γ subunit activates PLC, leading to local production of IP3 and DAG from PIP2. IP3 activates calcium channels which results in a release of calcium. RGS proteins enhance the GTPase activity of the Gα-subunit, controlling the rate of GTP hydrolysis (4). This promotes the formation of the inactive G-protein and subsequently terminates chemokine signalling (5).