A screening method (yeast two-hybrid system) used to find proteins that interact with one another. Both are expressed in yeast as fusion proteins, one with the DNA-binding site of the GAL4 transcription factor, and the other with the transcriptional activator domain of GAL4. If the two proteins interact then the two GAL4 domains are brought together and will trigger expression of a reporter gene (usually LacZ) downstream of the GAL4 promoter. Similar systems using other transcription factors have been developed. Interactions identified using the system need to be confirmed by other methods such as a pull-down assay.
Subjects: Medicine and Health.