Patent ID: 8865421

Claim:
A method for screening a candidate compound for modulating the binding of a nuclear hormone receptor to a second protein component that binds to the nuclear hormone receptor to form a complex to initiate transcription, comprising: (a) using a cell in an assay medium transformed with first and second genetic constructs having regulatory sequences functional in said cell for expression of said constructs, (b) said method employing first and second fragments of β-galactosidase which when complexed form an active enzyme, one of said fragments being an enzyme donor (“ED”) and the other of said fragments being an enzyme acceptor (“EA”) that is larger than said ED, (c) said first genetic construct encoding a first fusion protein of a first fragment of said β-galactosidase fused to said nuclear hormone receptor to serve as a surrogate for said nuclear hormone receptor; (d) said second genetic construct encoding a second fusion protein of said second fragment of β-galactosidase fused to said second protein component, wherein said second protein component is selected from the group consisting of (i) coactivator, (ii) corepressor, (iii) member of a homodimer, and (iv) member of a heterodimer, of said nuclear hormone receptor; (e) incubating said cell in said assay medium with a candidate compound for sufficient time for any binding between said first fusion protein fused to a nuclear hormone receptor and said second fusion protein, fused to said second enzyme fragment, that binds to the nuclear hormone receptor to form a complex to initiate transcription, to occur, said binding causing formation of active β-galactosidase; (f) adding a β-galactosidase substrate that provides for a signal that is detectable; and (g) determining said signal as a measure of the modulation resulting from said binding by said candidate compound, wherein binding results in a signal and a candidate compound modulating binding modulates said signal.