Unravelling the structural impact of progesterone receptor mutations in myoma and progesterone intolerance through...

Progesterone (P4) is a steroid hormone involved in the regulation of female reproductive functions. The endogenous progesterone receptor (PR), a member of the nuclear receptor family of ligand-dependent transcription regulators responsible for P4 action in the body through the 'ligand binding domain' (LBD). PR isoforms, PR-A and PR-B, are encoded by a single gene, PGR and variations in this gene can disrupt cellular signaling. In the current study, putative disease-causing mutations on PR has been identified through computationally and its mechanistic effects were explored using structural bioinformatics tools. Studies suggested that 11 of 66 missense variants (within the LBD) induce structural destabilization and were identified as potentially deleterious. Our ensemble docking suggested that these variations have a limited impact on P4 binding, however they significantly disrupt the binding of co-activators as evident by the protein-peptide docking. The binding of co-activators to the PR is the determining factor for the P4 signaling. Finally, based on the free energy of binding, we proposed two variations such as R869H and C798Y could cause myoma and progesterone tolerance conditions respectively. These findings were further validated through the use of allostery predictions. Our results reveal distinct mechanisms by which PR mutations modulate receptor function, laying the framework for future mechanistic studies and therapeutic development for PR-associated reproductive disorders.