Biochemistry Terms Starting With Y

Yeast Two-Hybrid Assay is a molecular technique that detects protein-protein interactions by fusing two proteins of interest to separate domains of a transcription factor in yeast cells, activating a reporter gene only when the two proteins physically bind each other.

Scientists typically use Saccharomyces cerevisiae as the host organism because its transcriptional machinery separates DNA-binding and activation functions into distinct modular domains that can be exploited independently. The assay splits the GAL4 transcription factor into a DNA-binding domain fused to a bait protein and an activation domain fused to a prey protein, with reporter gene transcription occurring only when bait and prey interact and reconstitute GAL4 activity. Screening human protein libraries with this method has identified approximately 80,000 binary interactions from combinations of around 8,000 different proteins, revealing molecular networks underlying cell division, signaling, and disease.