TR-FRET
coactivator recruitment ligand binding assay with RORγt
(unligated and ligated) by titration of various orthosteric and allosteric
ligands. (A) Apo (unligated) RORγt protein. (B) GW9662-ligated
RORγt. (C) Compound 9-ligated RORγt. (D)
Compound 19-ligated RORγt. (E). Compound 20-ligated RORγt. Data recorded in triplicate from two
independent experiments (one representative data set shown). Error
bars represent the SD of the mean. Abbreviations: n.a., not active.
(F/G) Schematic representation of the TR-FRET coactivator recruitment
assay, using the ligated protein. (F) Orthosteric ligand binding will
be occluded, showing no effect on the initial coactivator recruitment
capacity. (G) Allosteric ligand binding will result in reduced coactivator
binding and therefore a lower FRET pairing. (H) Chemical structures
of orthosteric agonists (cholesterol (CHL), desmosterol (DSM), and
20α-hydroxycholesterol (20-OH)), orthosteric inverse agonist
digoxin, and allosteric inverse agonists MRL-871 and FM26.