Fig. 6.

CNP stimulates αGSU promoter activity in a MEK-dependent manner. a GH3 cells were transiently transfected with 2.5 μg αGSU promoter and stimulated with the indicated concentrations of CNP or 1 mM db-cGMP. Cells were harvested after 8 h and protein extracts assayed for luciferase activity. Data shown are means ± SEM of three independent experiments, each performed in triplicate and are expressed as fold increase over basal. b GH3 cells transiently transfected with αGSU promoter (as above) were pre-treated with the indicated concentration of U0126 for 30 min prior to stimulation with CNP (100 nM). Cells were harvested after 8 h and protein extracts assayed for luciferase activity. Data shown are means ± SEM of three independent experiments, each performed in triplicate and are expressed as fold increase over control response to CNP (*P < 0.1, ***P < 0.001, ****P < 0.0001; significantly different from control response, as determined by Bonferonni’s multiple comparisons test). c CNP enhances phosphorylation of ERK1/2 pathway proteins. GH3 cells were stimulated with CNP (100 nM) for up to 90 min, prior to extraction of total proteins and Western blotting for the indicated target proteins. Each autoradiograph is representative of at least three independent experiments