The AGGACA sequence within the −67/−34 bp region is not required for COUP-TFII binding and activation of the Amhr2 promoter. (A) Representation of the −1486/+77 bp Amhr2 promoter showing the two previously characterized SF1 elements (open oval) and the COUP-TFII–responsive region (−67/−34 bp, filled rectangle). Sequence alignment of the −67/−34 bp region from various species (mouse, rat, human, orangutan, chimp) revealed a potential binding site (box) for nuclear receptors (NREs; AGGACA or AGGATG). An asterisk corresponds to a species-conserved nucleotide compared with the mouse sequence. (B) MA-10 Leydig cells were cotransfected with 50 ng of an empty expression vector (−, open bars) or an expression vector for COUP-TFII (+, filled bars) along with 400 ng of various Amhr2 reporter constructs: −67/+77 bp WT, −67/+77 bp harboring a mutation (AGGACA → AaagCA) in the potential NRE (M1), and −34/+77 bp. The NRE is represented by a black diamond (WT), and a large × represents the mutation. Results are shown as fold activation over control (±SEM). For each reporter: #P < 0.05, vs its control (empty expression vector, value set at 1, filled bar over open bar); *P < 0.05, for the activation by COUP-TFII of each reporter compared with that of the −34 bp reporter. (C) DNA pulldown assays were performed using oligonucleotides containing a high-affinity COUP-TFII direct repeat 1 sequence (HA-DR1) or oligonucleotides that contain the −67/−34 bp sequence of the Amhr2 promoter either WT or harboring a trinucleotide mutation in the potential NRE (AGGACA → AaagCA, M1) along with nuclear extracts from MA-10 Leydig cells. Western blots were used to detect COUP-TFII. Input corresponds to 25 µg of the nuclear extracts used in the DNA pulldown assay (n = 3).