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Updated: Aug 2, 2026
Identification of Growth Inhibition Phenotypes Induced by Expression of Bacterial Type III Effectors in Yeast
Published on: March 30, 2010
Expression of microbial virulence proteins in Saccharomyces cerevisiae models mammalian infection
1Departments of Medicine and Microbiology, University of Washington, HSB K116, Box 357710, Seattle, WA 98195, USA.
Abstract:
Bacterial virulence proteins that are translocated into eukaryotic cells were expressed in Saccharomyces cerevisiae to model human infection. The subcellular localization patterns of these proteins in yeast paralleled those previously observed during mammalian infection, including localization to the nucleus and plasma membrane. Localization of Salmonella SspA in yeast provided the first evidence that SspA interacts with actin in living cells. In many cases, expression of the bacterial virulence proteins conferred genetically exploitable growth phenotypes. In this way, Yersinia YopE toxicity was demonstrated to be linked to its Rho GTPase activating protein activity. YopE blocked polarization of the yeast cytoskeleton and cell cycle progression, while SspA altered polarity and inhibited depolymerization of the actin cytoskeleton. These activities are consistent with previously proposed or demonstrated effects on higher eukaryotes and provide new insights into the roles of these proteins in pathogenesis: SspA in directing formation of membrane ruffles and YopE in arresting cell division. Thus, study of bacterial virulence proteins in yeast is a powerful system to determine functions of these proteins, probe eukaryotic cellular processes and model mammalian infection.
Insights
Researchers modeled human infection by expressing bacterial virulence proteins in yeast. This study revealed new insights into bacterial protein functions and eukaryotic cellular processes, highlighting yeast as a powerful infection model.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Bacterial virulence proteins are crucial for pathogen invasion into host cells.
- Understanding the function and interactions of these proteins is key to combating infectious diseases.
- Existing models for studying bacterial virulence proteins in eukaryotic systems have limitations.
Purpose of the Study:
- To utilize Saccharomyces cerevisiae (yeast) as a model system for studying bacterial virulence proteins.
- To investigate the subcellular localization and functional effects of bacterial virulence proteins in a eukaryotic host.
- To gain new insights into the roles of bacterial virulence proteins in pathogenesis and their interactions with host cellular machinery.
Main Methods:
- Expression of bacterial virulence proteins (e.g., Salmonella SspA, Yersinia YopE) in Saccharomyces cerevisiae.
- Analysis of subcellular localization patterns of bacterial proteins within yeast cells.
- Assessment of genetically exploitable growth phenotypes conferred by bacterial protein expression.
- Investigation of protein interactions, such as SspA with the actin cytoskeleton.
Main Results:
- Subcellular localization of bacterial virulence proteins in yeast mirrored patterns observed in mammalian cells.
- Salmonella SspA was shown to interact with actin in living yeast cells, providing novel mechanistic insights.
- Yersinia YopE exhibited toxicity linked to its Rho GTPase activating protein activity, affecting yeast cytoskeleton and cell cycle.
- Bacterial protein expression conferred exploitable growth phenotypes, facilitating functional studies.
Conclusions:
- Saccharomyces cerevisiae serves as a powerful and effective model for studying bacterial virulence proteins and modeling mammalian infection.
- The study provides new functional insights into SspA (membrane ruffles) and YopE (cell division arrest) in pathogenesis.
- Investigating bacterial virulence proteins in yeast offers a valuable approach to probe eukaryotic cellular processes and identify therapeutic targets.
