Ablation of p21-activated kinase-1 in mice promotes isoproterenol-induced cardiac hypertrophy in association with activation of Erk1/2 and inhibition of protein phosphatase 2A

► ISO-treated Pak-1-KO hearts are highly susceptible to cardiac hypertrophy. ► Pak-1/PP2A and Erk1/2 bind to carry out their biological function in the heart. ► Erk1/2 activation is increased in ISO-treated Pak-1-KO hearts. ► Pak-1 has an inhibitory role on Erk1/2 activation via PP2A. ► FR180204, a selective inhibitor of Erk1/2, attenuates myocardial hypertrophy in ISO-treated Pak-1-KO mice.