In Vivo Protein-Protein Interaction Assays: Beyond Proteins.

Overview

The scope of cell-based assays is being expanded to allow the detection of interactions between proteins and DNA, RNA, or small molecules. The yeast two-hybrid assay, which normally detects protein-protein interactions, can be modified to detect interactions between ligands (the two dark yellow shapes in the diagram) and receptors (DHFR or GR). A small bridging molecule (made up of the ligands joined together) is used to join two fusion proteins (DHFR-DBD and AD-GR), thereby activating the reporter gene.