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Crystal structure of human PPARgamma ligand binding domain Y473E mutantCrystal structure of human PPARgamma ligand binding domain Y473E mutant
Structural highlights
DiseasePPARG_HUMAN Note=Defects in PPARG can lead to type 2 insulin-resistant diabetes and hyptertension. PPARG mutations may be associated with colon cancer. Defects in PPARG may be associated with susceptibility to obesity (OBESITY) [MIM:601665. It is a condition characterized by an increase of body weight beyond the limitation of skeletal and physical requirements, as the result of excessive accumulation of body fat.[1] Defects in PPARG are the cause of familial partial lipodystrophy type 3 (FPLD3) [MIM:604367. Familial partial lipodystrophies (FPLD) are a heterogeneous group of genetic disorders characterized by marked loss of subcutaneous (sc) fat from the extremities. Affected individuals show an increased preponderance of insulin resistance, diabetes mellitus and dyslipidemia.[2] [3] Genetic variations in PPARG can be associated with susceptibility to glioma type 1 (GLM1) [MIM:137800. Gliomas are central nervous system neoplasms derived from glial cells and comprise astrocytomas, glioblastoma multiforme, oligodendrogliomas, and ependymomas. Note=Polymorphic PPARG alleles have been found to be significantly over-represented among a cohort of American patients with sporadic glioblastoma multiforme suggesting a possible contribution to disease susceptibility. FunctionPPARG_HUMAN Receptor that binds peroxisome proliferators such as hypolipidemic drugs and fatty acids. Once activated by a ligand, the receptor binds to a promoter element in the gene for acyl-CoA oxidase and activates its transcription. It therefore controls the peroxisomal beta-oxidation pathway of fatty acids. Key regulator of adipocyte differentiation and glucose homeostasis. Acts as a critical regulator of gut homeostasis by suppressing NF-kappa-B-mediated proinflammatory responses.[4] [5] [6] Publication Abstract from PubMedLigands bind to an occluded orthosteric ligand-binding pocket within the nuclear receptor ligand-binding domain. Molecular simulations have revealed theoretical ligand entry/exit pathways to the orthosteric pocket; however, it remains unclear whether ligand binding proceeds through induced fit or conformational selection mechanisms. Here, using nuclear magnetic resonance spectroscopy, isothermal titration calorimetry, and surface plasmon resonance analysis, we provide evidence that structurally distinct agonists bind peroxisome proliferator-activated receptor gamma (PPARgamma) via a two-step induced fit mechanism involving an initial fast kinetic step followed by a slow conformational change. The agonist encounter complex binding pose is suggested in crystal structures where ligands bind to a surface pore suggested as a ligand entry site in molecular simulations. Our findings suggest an activation mechanism for PPARgamma whereby agonist binding occurs through an initial encounter complex followed by a transition of the ligand into the final binding pose within the orthosteric pocket, inducing a transcriptionally active conformation. Structural mechanism underlying ligand binding and activation of PPARgamma.,Shang J, Kojetin DJ Structure. 2021 Sep 2;29(9):940-950.e4. doi: 10.1016/j.str.2021.02.006. Epub 2021, Mar 12. PMID:33713599[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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