FIGURE 7.

Model for PPARγ transactivation of the UCP3 and -2 genes through intrachromosomal looping. Our data show that the +1950 PPRE in intron 1 of the Ucp3 genes is the main PPARγ (PPγ) binding site in the Ucp3 and -2 loci in murine adipocytes and indicate a model for transactivation of both loci by PPARγ/RXR binding to this PPRE. According to this model PPARγ/RXR bind to the PPRE in intron 1 of the Ucp3 gene and loop out to simultaneously interact indirectly with intron 1 of the Ucp2 gene through a transcription factor complex at +400 relative to the transcription start site.