PPAR response elements (PPREs) for PPARα in the rat NHE1 promoter region. (A) A schematic representation of the rat NHE1 promoter (−3106 to −1). Transcription start site is marked by +1. The nucleotide positions of the black box indicate the localization of the putative PPREs. (B) Nucleotide sequences surrounding the rat malonyl-CoA decarboxylase (MCD) PPREs and putative NHE1 PPREs. We used two well-known PPREs in the rat MCD promoter region in the ChIP assay as positive controls. Nucleotide sequences of MCD PPREs are shown in bold. Nucleotide sequences of putative NHE1 PPREs have a gray background. Primers designed for ChIP are underlined. Two sets of primers specific for −322/−248 and −207/−127 regions (C1 and C2) containing PPREs in the rat MCD promoter and three sets of primers specific for −2889/−2802, −2388/−2289 and −615/−531 regions (N1, N2 and N3) containing putative PPREs in the rat NHE1 promoter were used in the PCR. (C) ChIP analysis of the rat NHE1 promoter DNA. ChIP analysis was performed with an anti-PPARα antibody. The PCR products were detected by agarose gel electrophoresis. M, DNA marker (base pair [bp]). (D) The luciferase reporter assay of the truncated rat NHE1 promoter in the pcPPAR-transfected NRK-52E cells. The pcPPAR-transfected cells were transfected with pGL3 vector, −2889/−1 NHE1-LUC, −2388/−1 NHE1-LUC or a −615/−1 NHE1-LUC construct as indicated. Results are means ± SD (n = 3). *P < 0.05 by Student t test.