Corticosteroid-induced chromatin loop dynamics at the FKBP5 gene

Area of Science:

• Genomics
• Epigenetics
• Molecular Biology

Background:

• FKBP5 is a glucocorticoid-inducible gene linked to psychiatric disorders.
• Understanding its regulatory mechanisms is crucial for psychiatric research.

Purpose of the Study:

• To investigate chromatin interaction frequencies within the FKBP5 topologically associated domain (TAD).
• To elucidate the structural organization and regulatory elements of the FKBP5 locus.

Main Methods:

• Employed 15 one-to-all chromatin capture viewpoints.
• Analyzed gene promoters, enhancers, introns, and CTCF-loop anchors.

Main Results:

• Identified a "one-TAD-one-gene" structure for FKBP5, with its promoter and enhancers within the TAD.
• Discovered two nested CTCF loops coordinating the TAD, with loop extension linked to transcription.
• FKBP5 TAD boundaries are resilient to stimulation and contain heterochromatin, while smaller genes are present.

Conclusions:

• The FKBP5 TAD exhibits a stable, organized structure despite dynamic enhancer-promoter interactions.
• Genetic and epigenetic variations influencing FKBP5 expression likely reside within a 240-kb region encompassing the TAD and its boundaries.