Regulation of gene activity is mainly concerned with nuclear organization.
The associations of the regulatory regions of the genome with the nuclear lamina have been identified.
Information about these lamina-associated domains (LADs) directed to the nuclear lamina is sparse.
Chromosomal insertion site system was used to identify small sequences from borders of fibroblast-specific variable LADs that are sufficient to target these ectopic sites to the nuclear periphery.
YY1 (Ying-Yang1) binding sites as enriched in relocating sequences were identified.
There was no lamina association as lamina A was not knocked down like YY1 or lamin A/C.
In addition, targeted recruitment of YY1 proteins facilitated ectopic LAD formation dependent on histone H3 lysine 27 trimethylation and histone H3 lysine di- and trimethylation.
The results also reveal that endogenous loci appear to be dependent on lamin A/C, YY1, H3K27me3, and H3K9me2/3 for maintenance of lamina-proximal positioning.