Final answer:
The Yeast-Two Hybrid system is a biotechnological tool used to detect protein-protein interactions by exploiting the mating signaling pathway of yeasts. Proteins of interest are fused to either a DNA-binding or activation domain, and interaction triggers a detectable reporter gene expression, illuminating the proteins' interaction within the cell.
Step-by-step explanation:
The Yeast-Two Hybrid system is a molecular biology technique used to study protein-protein interactions. This system utilizes the properties of yeasts, which are eukaryotic fungi, capable of both asexual and sexual reproduction. Yeast cells can exist in both haploid and diploid states, where haploid cells may secrete a signaling molecule known as a mating factor to find compatible cells for mating. The presence of mating factor triggers a series of intracellular signals, leading to changes that facilitate mating between yeast cells.
By understanding the normal mating process of yeast, researchers have developed the Yeast-Two Hybrid system to analyze interactions between proteins. Yeast cells are engineered to express two hybrid proteins: one is a 'bait' protein fused to a DNA-binding domain, and the other is a 'prey' protein attached to a transcriptional activation domain. If the bait and prey proteins interact, they bring the DNA-binding and activation domains close enough to initiate transcription of a reporter gene, which can then be easily detected.
This technique is widely used for studying the protein interactions that are crucial to many cell signaling systems, including those that are homologous to higher multicellular organisms. Thanks to yeast's rapid growth and predictable behavior, along with its similarity to cell processes found in humans, the Yeast-Two Hybrid system is a powerful tool for understanding the functional networks that underpin many biological systems.