- ERK2 mitogen-activated protein kinase binding, phosphorylation, and regulation of the PDE4D cAMP-specific phosphodiesterases. The involvement of COOH-terminal docking sites and NH2-terminal UCR regions. MacKenzie, S.J., Baillie, G.S., McPhee, I., Bolger, G.B., Houslay, M.D. J. Biol. Chem. (2000)