Figure 3.

Effect of R-roscovitine on AQP2 S256 and S261 phosphorylation in MDCK-hAQP2 cells. MDCK-hAQP2 cells were left untreated (CTR) or stimulated with forskolin (F) in the absence (R) or the presence of R-roscovitine (RF). After treatments, cells were lysed and subjected to immunoprecipitation. Immunocomplexes were analyzed by immunoblotting for total AQP2, AQP2-pS256, and AQP2-pS261. R-roscovitine treatment increases AQP2-pS256, whereas reduces AQP2-pS261. Signals were semiquantified by densitometry (lower panel). *Samples significantly (means±SEMs; P<0.05) different from controls; ^#sample significantly (means±SEMs; P<0.05) different from forskolin condition. No change in the expression of the housekeeping protein actin was detected within the R-roscovitine incubation time used in this study.