What is the Difference Between Yeast One Hybrid and Yeast Two Hybrid

The key difference between yeast one hybrid and yeast two hybrid is that yeast one hybrid is an in vitro based assay to analyze DNA-protein interactions while yeast two hybrid is an in vitro based assay to analyze protein-protein interactions.

Studying the interactions between cellular molecules can help to define recognition sites involved in gene expression and protein pathways. DNA and protein interactions are integral to cellular processes such as DNA modifications and transcriptional regulation, etc. On the other hand, protein and protein interactions play vital roles in cellular processes such as replication, transcription, translation, and signal transduction. Therefore, it is critically important to identify these interactions of cellular molecules through different assays. Yeast one hybrid and yeast two hybrid are two in vitro based assays to analyze DNA-protein and protein-protein interactions.

CONTENTS

1. Overview and Key Difference
2. What is Yeast One Hybrid
3. What is Yeast Two Hybrid
4. Similarities – Yeast One Hybrid and Yeast Two Hybrid
5. Yeast One Hybrid vs Yeast Two Hybrid in Tabular Form
6. Summary – Yeast One Hybrid vs Yeast Two Hybrid

What is Yeast One Hybrid?

Yeast one hybrid (Y1H) is an in vitro based assay to analyze intracellular DNA-protein interactions. This method was first established by Wang and Reed in 1993. Since then, it has shown a greater power in biological research. In this assay, there are two main components: DNA bait and protein preys.

Figure 01: Yeast One Hybrid

In the procedure, a DNA sequence (DNA bait) is first cloned upstream of two different reporters (HIS3, LacZ). These reporter constructs are integrated into the genome of a yeast strain. Transcriptional factors are taken as protein preys. Transcriptional factors are fused to the transcriptional activation domain (AD) of yeast Gal4 transcriptional factor in order to make hybrid proteins. This entire hybrid protein is integrated into a plasmid before introducing it into the yeast strain. After the introduction of the recombinant plasmid, when the transcriptional factor interacts with the DNA fragment, the AD moiety activates the reporter gene expression (HIS3or LacZ). Sequencing the plasmids allows the identification of the transcriptional factor that can bind to the DNA fragment. Recently, yeast one hybrid method was used to research disease diagnosis. Therefore, in future, this assay will be more widely used in scientific research and medical treatments.

What is Yeast Two Hybrid?

Yeast two hybrid (Y2H) is an in vitro based assay to analyze intracellular protein and protein interactions. This method was originally found by Stanley Fields and Ok-Kyu Song in 1989. This technique detects protein-protein interactions using the Gal4 transcription factor of the yeast.

Figure 02: Yeast Two Hybrid

In this method, two fusions (hybrids) are first constructed using proteins of interest: fusing one protein with DNA binding domain (DBD) and by fusing the other protein with the activator domain (AD) of the Gal4 transcription factor. The protein fused with DBD is known as bait while, the protein fused with AD is known as prey. In the yeast strain, upon the interaction of the bait and prey, the DBD and AD are brought in close proximity to generate a functional Gal4 transcription factor upstream of the reporter gene. The functional transcription factor activates reporter gene expression. Furthermore, this method is currently used to screen the interactions of integral membrane proteins in mammalian cells.

What are the Similarities Between Yeast One Hybrid and Yeast Two Hybrid?

  • Yeast one hybrid and yeast two hybrid are two in vitro based assays to analyze DNA-protein and protein-protein interactions.
  • These assays use yeast strains.
  • Both assays use the activation domain (AD) of the Gal4 transcription factor.
  • They use reporter gene (HIS3, or LacZ) expression to detect interactions.
  • They have bait and prey.
  • Both assays are highly useful in modern biological research.

What is the Difference Between Yeast One Hybrid and Yeast Two Hybrid?

Yeast one hybrid is an in vitro based assay to analyze DNA and protein interactions while yeast two hybrid is an in vitro based assay to analyze protein and protein interactions. Thus, this is the key difference between yeast one hybrid and yeast two hybrid. Furthermore, in yeast one hybrid, bait is a DNA fragment, and prey is a protein molecule. On the other hand, in yeast two hybrid, both bait and prey are protein molecules.

The below infographic lists the differences between yeast one hybrid and yeast two hybrid in tabular form for side by side comparison.

Summary – Yeast One Hybrid vs Yeast Two Hybrid

Yeast one hybrid and yeast two hybrid are two important in vitro based assays. Yeast one hybrid is an in vitro based assay to analyze DNA and protein interactions while yeast two hybrid is an in vitro based assay to analyze protein and protein interactions. Thus, this is the key difference between yeast one hybrid and yeast two hybrid.