1,25D promotes BBM NaPi2a localization. (A) NaPi2a mRNA expression. Data represent the mean ± SEM. *P < 0.05 vs WT; #P < 0.05 vs Hyp control mice. (B) NaPi2a protein expression in renal BBMs from Hyp mice treated or not with 1,25D. The migration of the 100-kDa [alkaline phosphatase (AlkPhos) control] and 75-kDa markers is indicated. (C) NaPi2a protein expression in BBM of Hyp renal tubules treated in vitro with 1,25D or vehicle for 1 h. Alkaline phosphatase (AlkPhos) is used as control. Data are representative of that obtained from four Hyp mice; data from one male and one female Hyp mouse are shown. (D) Immunoprecipitation of NaPi2a from renal cortical lysates with anti-NHERF1. NaPi2a and NHERF1 protein input. The migration of the 75- and 50-kDa markers is indicated. Data are representative of that obtained from three mice per group. Hyp C, vehicle-treated Hyp mice; HypD1h, Hyp mice treated with 1,25D for 1 h; HypD18h, Hyp mice treated with 1,25D for 18 h; Npt-KO, Npt2 knockout; WT, vehicle-treated WT mice.