The mechanism regulating these differential functions is under intense investigation and could be related to a diverse transcriptional activity but also to the ability to bind the RBP-jk/CBF-1 complex and/or to displace corepressors from the transcriptional complex.
Furthermore, when the triplex is formed in the middle of a gene, mRNA elongation is stopped just before the TTS, which indicates that triplex binding is strong enough to displace complex transcriptional machinery [ 24, 25].
Structural studies have shown that this complex exists in a distribution of conformations, with the WASP NPF and coronin inhibitor contacting distinct regions of the complex, thereby exerting opposing effects to displace the equilibrium towards respectively a closed (active) or open (inactive) form [11].
Interestingly, increasing amounts of PUF60 binding to the RNA appeared to displace the U2AF complex, as evidenced by the decrease in the U2AF RNA complex.
The resulting accumulation of PPARγ2 is a prerequisite to the expression of C/EBPα, since active PPARγ2 has the ability to displace a repressive complex composed of mSin3A/histone deacetylase (HDAC 1 from the cebpα promoter [29].
Ectopic expression of an intergenic sense nc-rRNA from −142 to −40 nucleotides has been shown to displace nucleolar remodeling complex and to upregulate the 47S rRNA in mouse fibroblast cells.
Surface alkylation allows the formation of a stable, isolable, graphite intercalation compound of tetra-n-ethylammonium, (C2H5 4N+ for the first time, by chemical surface passivation of [Na en 1.0]C15 (en = ethylenediamine) with R4N+, R = C6H13, C7H15 or C8H17, followed by an ion exchange reaction to displace the Na en)+ complex with (C2H5 4N+.
This confirms a specific involvement of p300/CBP protein as a p53 coactivator, which is functionally different form PCAF. It is possible that PCAF might be able to displace p300 from the complex and thus prevent the effect of p300.
Thus, it is likely that rosiglitazone-mediated activation of PPARγ1 in DLK-depleted cells is sufficient to displace the repressive mSin3A/HDAC1 complex from the cebpα promoter and allow the expression of C/EBPα, which in turn induces PPARγ2, the most potent regulator of adipogenesis [44].
