Figure 6.

Co-activation of G_i and EGF signaling increased the activity and expression level of MKP-1. (a) Cos-7 cells expressing ORL₁R were stimulated individually or simultaneously with OFQ (100 nM) and EGF (100 ng ml⁻¹) for 30 min, or (b) co-stimulated with the two agonists for increasing durations before determining the associated MKP-1 activities in the absence or presence of Na₃VO₄ (200 μM). Data shown represent the mean±s.e. from three separate experiments (a) or the averaged values of two separate experiments (b). (c) The time-dependent expression pattern of MKP-1 in response to agonist treatments was detected by anti-MKP-1 M-18 antiserum, which recognizes the C-terminus of MKP-1.