Retinoic acid receptors: structural basis for coregulator interaction and exchange

Area of Science:

• Molecular biology
• Genetics
• Pharmacology

Background:

• Retinoic acid receptors (RARs) form heterodimers with retinoid X receptors (RXRs).
• RARs are crucial regulators of gene expression, controlling cell growth, differentiation, survival, and death.
• These receptors are significant drug targets due to their regulatory roles.

Purpose of the Study:

• To review the structural determinants governing RAR interactions with coregulators.
• To examine these interactions in both individual receptors and RAR-RXR heterodimers.
• To discuss how pharmacological ligands modulate these associations.

Main Methods:

• Structural analysis of receptor-coregulator interactions.
• Review of molecular mechanisms of transcriptional regulation by RARs.
• Examination of ligand-induced conformational changes and their effects.

Main Results:

• Unliganded RARs recruit corepressors, leading to histone deacetylase activity and gene repression.
• Ligand binding induces conformational changes, releasing corepressors and recruiting coactivators.
• Coactivator recruitment facilitates histone acetylase activity, promoting gene transcription.

Conclusions:

• The dynamic exchange of coregulators, modulated by ligand binding, is central to RAR biological functions.
• Understanding the structural basis of these interactions is key to developing targeted therapies.
• Pharmacological ligands fine-tune RAR-coregulator associations, offering therapeutic potential.