Putative response elements of interest were mutated using a PCR-based strategy. The putative GRE sequence CAAGAATGAACATTGAACT at position −87 of the SEPP1 promoter (GRE #1) was mutated to the sequence CAAGAATGACTATTGAACT using the primer 5′-GGTCACTGCAAGAATGACTATTGAACTTTGGACTATAC-3′ and its complementary sequence (exchanged nucleotides are bold and underlined). The putative GRE sequence TCAGAGTGTGCT at position −24 of the SEPP1 promoter (GRE #2) was mutated to the sequence TCAGAGGATGCT using the primer 5′-GGACTATAAATATCAGAGGATGCTGCTGTGGCTTTGTG-3′ and its complementary sequence. These mutations should eliminate activity of potential GRE half sites (Nordeen et al. 1990). The putative retinoid responsive element sequence ACATTGAACTTTGG at position −73 of the SEPP1 promoter (RRE) was mutated to the sequence ACATCTTACTTTGG using the primer 5′-CTGCAAGAATGAACATCTTACTTTGGACTATACCTGAGG-3′ and its complementary sequence. The FoxO1a binding sequence GTAAACAA at position −46 of the SEPP1 promoter was mutated to the sequence GTAAATCA using the primter 5′-CCTGAGGGGTGAGGTAAATCACAGGACTATAAATATCAGAG-3′ and its complementary sequence.
