Patent ID: 7033768

Claim:
A method for determining whether a first test protein interacts with a second test protein, said method comprising: a) providing in a cell: i) a first counterselectable reporter gene operably linked to a first DNA binding protein recognition site or a first selectable/counterselectable reporter gene operably linked to a first DNA binding protein recognition site; ii) a second counterselectable reporter gene operably linked to a second DNA binding protein recognition site or a second selectable/counterselectable reporter gene operably linked to a second DNA binding protein recognition site, wherein said first reporter gene and said second reporter gene are identical, wherein said first reporter gene and said second reporter gene are operably linked to different promoters, and wherein the sequences of said first DNA binding protein recognition site and said second DNA binding protein recognition site are identical; iii) a first fusion gene that expresses a first hybrid protein, said first hybrid protein comprising a first test protein covalently bonded to a DNA binding moiety that specifically binds to said DNA binding protein recognition site; iv) a second fusion gene that expresses a second hybrid protein, said second hybrid protein comprising a second test protein covalently bonded to a gene activating moiety; and b) detecting expression of said first reporter gene or said second reporter gene as a measure of the ability of said first test protein to interact with said second test protein.