Insights into pparγphosphorylation and its inhibition mechanism

PPARγrepresents a key target for the treatment of type 2 diabetes and metabolic syndrome. Synthetic antidiabetic drugs activating PPARγare accompanied by serious undesirable side effects related to their agonism. In the search for new PPARγregulators, inhibitors of PPARγphosphorylation on S245 mediated by CDK5 represent an opportunity for the development of an improved generation of antidiabetic drugs acting through this nuclear receptor. We have employed a multidisciplinary approach, including protein-protein docking, X-ray crystallography, NMR, HDX, MD simulations, and site-directed mutagenesis to investigate conformational changes in PPARγthat impair the ability of CDK5 to interact with PPARγand hence inhibit PPARγphosphorylation. Finally, we describe an alternative inhibition mechanism adopted by a ligand bound far from the phosphorylation site.