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Updated: Jul 10, 2026
Split-Ubiquitin Based Membrane Yeast Two-Hybrid (MYTH) System: A Powerful Tool For Identifying Protein-Protein Interactions
Published on: February 1, 2010
A yeast two-hybrid system reconstituting substrate recognition of the von Hippel-Lindau tumor suppressor protein
Claudia Bex1, Katja Knauth, Silvia Dambacher
1Max Planck Institute of Biochemistry, Department of Molecular Cell Biology, Am Klopferspitz 18, 82152 Martinsried, Germany.
Abstract:
The von Hippel-Lindau tumor suppressor protein (pVHL) is inactivated in the hereditary cancer syndrome von Hippel-Lindau disease and in the majority of sporadic renal carcinomas. pVHL is the substrate-binding subunit of the CBC(VHL) ubiquitin ligase complex that negatively regulates cell growth by promoting the degradation of hypoxia-inducible transcription factor subunits (HIF1/2alpha). Proteomics-based identification of novel pVHL substrates is hampered by their short half-life and low abundancy in mammalian cells. The usefulness of yeast two-hybrid (Y2H) approaches, on the other hand, has been limited by the failure of pVHL to adopt its native structure and by the absence of prolylhydroxylase activity critical for pVHL substrate recognition. Therefore, we modified the Y2H system to faithfully reconstitute the physical interaction between pVHL and its substrates. Our approach relies on the coexpression of pVHL with the cofactors Elongin B and Elongin C and with HIF1/2alpha prolylhydroxylases. In a proof-of-principle Y2H screen, we identified the known substrates HIF1/2alpha and new candidate substrates including diacylglycerol kinase iota, demonstrating that our strategy allows detection of stable interactions between pVHL and otherwise elusive cellular targets. Additional future applications may include structure/function analyses of pVHL-HIF1/2alpha binding and screens for therapeutically relevant compounds that either stabilize or disrupt this interaction.
Insights
Researchers developed an improved yeast two-hybrid system to identify novel substrates of the von Hippel-Lindau tumor suppressor protein (pVHL), aiding cancer research.
Area of Science:
- Molecular Biology
- Cancer Biology
- Biochemistry
Background:
- The von Hippel-Lindau tumor suppressor protein (pVHL) is crucial in regulating cell growth and is frequently inactivated in cancers like von Hippel-Lindau disease and renal cell carcinoma.
- pVHL functions as part of the CBC(VHL) ubiquitin ligase complex, targeting hypoxia-inducible transcription factors (HIF1/2alpha) for degradation.
- Identifying novel pVHL substrates is challenging due to their low abundance and short half-lives, and traditional yeast two-hybrid (Y2H) methods are limited by pVHL's structural instability and lack of critical hydroxylase activity.
Purpose of the Study:
- To overcome the limitations of existing methods for identifying pVHL-interacting proteins.
- To develop a modified yeast two-hybrid system capable of accurately detecting interactions with pVHL and its substrates.
- To validate the modified system by identifying known and novel pVHL substrates.
Main Methods:
- Engineered a modified yeast two-hybrid (Y2H) system to enable the faithful reconstitution of pVHL's native structure and function.
- Co-expressed pVHL with essential cofactors Elongin B and Elongin C, and HIF1/2alpha prolylhydroxylases within the Y2H system.
- Performed a proof-of-principle Y2H screen to identify pVHL interacting partners.
Main Results:
- The modified Y2H system successfully identified known pVHL substrates, including HIF1/2alpha.
- The screen also identified novel candidate substrates, such as diacylglycerol kinase iota.
- The strategy demonstrated the ability to detect stable interactions between pVHL and previously elusive cellular targets.
Conclusions:
- The developed modified Y2H system effectively overcomes previous limitations, enabling the identification of pVHL substrates.
- This approach facilitates the discovery of new proteins interacting with pVHL, advancing our understanding of its role in cancer.
- Future applications include structural analyses of pVHL-HIF1/2alpha binding and screening for therapeutic compounds targeting this interaction.
