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Updated: Nov 19, 2025
Growth-based Determination and Biochemical Confirmation of Genetic Requirements for Protein Degradation in Saccharomyces cerevisiae
Published on: February 16, 2015
Reconstitution of Human Necrosome Interactions in Saccharomyces cerevisiae
Y Ji1, L A Ward1, C J Hawkins1
1Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3083, Australia.
Abstract:
The necrosome is a large-molecular-weight complex in which the terminal effector of the necroptotic pathway, Mixed Lineage Kinase Domain-Like protein (MLKL), is activated to induce necroptotic cell death. The precise mechanism of MLKL activation by the upstream kinase, Receptor Interacting Serine/Threonine Protein Kinase 3 (RIPK3) and the role of Receptor Interacting Serine/Threonine Protein Kinase 1 (RIPK1) in mediating MLKL activation remain incompletely understood. Here, we reconstituted human necrosome interactions in yeast by inducible expression of these necrosome effectors. Functional interactions were reflected by the detection of phosphorylated MLKL, plasma membrane permeabilization, and reduced proliferative potential. Following overexpression of human necrosome effectors in yeast, MLKL aggregated in the periphery of the cell, permeabilized the plasma membrane and compromised clonogenic potential. RIPK1 had little impact on RIPK3/MLKL-mediated yeast lethality; however, it exacerbated the toxicity provoked by co-expression of MLKL with a RIPK3 variant bearing a mutated RHIM-domain. Small molecule necroptotic inhibitors necrostatin-1 and TC13172, and viral inhibitors M45 (residues 1-90) and BAV_Rmil, abated the yeast toxicity triggered by the reconstituted necrosome. This yeast model provides a convenient tool to study necrosome protein interactions and to screen for and characterize potential necroptotic inhibitors.
Insights
Researchers developed a yeast model to study the necrosome, a cell death complex. This model successfully identified inhibitors of necroptosis, a form of programmed cell death, aiding future drug discovery.
Area of Science:
- Cellular biology
- Molecular mechanisms of cell death
- Biochemistry
Background:
- The necrosome complex mediates necroptosis, a programmed cell death pathway.
- The precise roles of Receptor Interacting Serine/Threonine Protein Kinase 1 (RIPK1) and Receptor Interacting Serine/Threonine Protein Kinase 3 (RIPK3) in Mixed Lineage Kinase Domain-Like protein (MLKL) activation are not fully understood.
- Understanding necrosome assembly and activation is crucial for developing targeted therapies.
Purpose of the Study:
- To reconstitute human necrosome complex interactions in yeast.
- To utilize a yeast model for studying necrosome function and MLKL activation.
- To screen for potential inhibitors of necroptosis.
Main Methods:
- Inducible expression of human necrosome components (RIPK1, RIPK3, MLKL) in yeast.
- Assessing functional interactions through detection of phosphorylated MLKL, plasma membrane permeabilization, and reduced proliferative potential.
- Testing the efficacy of known necroptotic inhibitors (necrostatin-1, TC13172, M45, BAV_Rmil) in the yeast model.
Main Results:
- Overexpression of necrosome effectors in yeast recapitulated key aspects of necrosome function, including MLKL aggregation, plasma membrane permeabilization, and compromised cell viability.
- RIPK1 modulated toxicity, particularly with a mutated RIPK3 RHIM domain.
- The reconstituted necrosome in yeast was sensitive to known necroptotic inhibitors, validating the model's utility.
Conclusions:
- A functional human necrosome complex can be reconstituted in yeast, serving as a valuable tool for studying necroptosis.
- This yeast model facilitates the investigation of necrosome protein interactions and MLKL activation mechanisms.
- The model is effective for screening and characterizing small molecule and viral inhibitors of necroptosis.
