Fig. 3.

FMP-API-1 increases PKA activity without elevation of cAMP. a Dose-response studies of FMP-API-1. FMP-API-1 (100–1500 µM) was added to the basolateral side of the mpkCCD cells for 1 h. Representative blots of three independent experiments are shown. b Dose-response studies of H89. FMP-API-1 (900 µM) was added in the presence or absence of H89 (1–100 µM) for 1 h. The mpkCCD cells were pretreated with H89 for 1 h before FMP-API-1 stimulation. Representative blots of three independent experiments are shown. c No significant elevation of cAMP concentration in response to FMP-API-1. The mpkCCD cells were treated with FMP-API-1 (900 µM) for 1 h. Bars are mean values ± SD of three experiments. Asterisk indicates a significant difference, as compared with the control. Tukey, **p < 0.01. d The effects of FMP-API-1 on PKA localization. (Left) FMP-API-1 (900 µM) was added to the basolateral side of the mpkCCD cells for 1 h. The mpkCCD cells were then incubated with 1% Triton X-100 for 3 min before cell lysis and divided into a detergent-soluble cytosol fraction and an insoluble membrane fraction. Representative blots of three independent experiments are shown. (Right) Bands of PKA RIIα/β were quantified by densitometric analysis, and the results are presented in the bar graphs as the fold change, as compared with the values of the control cells. Bars are mean values ± SD of three experiments. Tukey, **p < 0.01