FIGURE 10.

Effects of β-arrestin shRNA on APJ stimulated ERK1/2 phosphorylation. HEK293 cells stably expressing APJ (A) or APJ-S348A (B) were transfected with the indicated shRNA. Serum-starved cells were treated with 100 nm apelin-13 and cell lysates were analyzed for ERK1/2 phosphorylation and β-arrestin (C). The densities of the bands corresponding to 44 and 42 kDa were quantified with an imaging densitometer, normalized to total ERK. The data correspond to the mean ± S.E. from four independent experiments. ***, p < 0.01 compared with the control treatment group.