Fig. 1.

Characterization of a nuclear receptor binding site in the nPE2 neuronal enhancer. (A) Alignment of mouse and human nPE2 with identical nucleotide positions highlighted in black. Grey brackets indicate mouse regions used as baits in one-hybrid screening (5’ and 3’ half probes). The consensus for nuclear receptor binding element NRBE is indicated with a black box. Probe A used in EMSA studies is depicted with a black line. (B) Alignment of nPE2 sequences encompassing NRBE from various mammalian species and their phylogenetic relationship. (C) Gel shift of probe A, which encompasses mouse NRBE, and bacterially-expressed Nr2f1 (increasing amounts) and Nr2f2. Control lanes include a probe A without cell extract (probe only) or with BL21 bacterial extract without recombinant nuclear receptor expression (cell extract). (D) Gel shift with Nr2f1 extracts and probes A and A*, the latter harboring a mutated NRBE site. (E) Gel shift with [³²]P-labelled probe A incubated with cell extracts expressing Nr2f1 in the presence of increasing amounts of cold probe A or cold probe A*.