Figure 6. Schematic representation of the sequence of events proposed for β-arrestin-dependent Erk1/2 activation by GPCRs.
β-arrestin, Raf and MEK are recruited to agonist-stimulated receptor, resulting in MEK activation. Active MEK phosphorylates β-arrestin2 at Thr383. This induces a movement of the β-arrestin2 350–393 segment away from the first β-strand of β-arrestin, leaving space for its interaction with the C-terminal domain of the receptor. Erk then binds to the complex and is activated by MEK. The dash circles represent activated enzymes.