Targeted Deficiency of the Transcriptional Activator Hnf1α Alters Subnuclear Positioning of Its Genomic Targets (original) (raw)
Figure 6
Summary model. Hnf1a−/−.
In the absence of Hnf1α, target nucleosomes exhibit increased trimethylated H3-Lys27, and are more likely to be located in peripheral nuclear domains with condensed chromatin enriched in methylated H3-Lys27. Hnf1a+/+: In wild-type cells, Hnf1α binding recruits complexes that lead to site-specific histone acetylation, H3-Lys4 methylation, and chromatin remodeling, while preventing trimethylation of H3-Lys27. This chromatin configuration is associated with relocalization to transcriptionally active, more centrally located nuclear subregions enriched in RNA polymerase II and H3-Lys4me2. We propose that activator-dependent local chromatin changes may be instrumental in gene positioning.