Patent ID: 6878524

Claim:
A method for detecting protein—protein interactions in a host cell cytoplasm by detecting transcriptional activation of a gene operably linked to a promoter sensitive to or transcriptionally inhibited by a transcription inhibitor, the method comprising the steps of: a) introducing a first recombinant expression construct encoding a first protein or protein-binding fragment thereof fused with the amino- or carboxyl-terminus of a transcriptional inhibitor; b) introducing a second recombinant expression construct encoding a second protein or protein-binding fragment thereof fused to a cytoplasm localization sequence, wherein upon interaction of the first and second proteins in the cell cytoplasm, said transcriptional inhibitor is localized to the cytoplasm, wherein transcription of a gene operably linked to a promoter that is sensitive to or regulated by said transcriptional inhibitor is increased; and c) detecting said increased transcription of said gene wherein said protein—protein interaction is detected thereby.