TCF- and LEF-binding motifs contained in the Klotho promoter. The DNA sequence of the promoter region of the Klotho gene. TCF/LEF (CTTTT, CTTTG, or CAAAG) consensus sequences are marked in bold type and underlined. The arrows indicate the starting location of the primers used to generate the promoter constructs. The transcription start site is marked as +1; CGC marks the translation start site. The PCR products were digested with KpnI and XhoI, and ligated into the KpnI and XhoI sites of the pGL3-basic vector .