[Bioassay for endocrine disruptors by using yeast two-hybrid system]

Area of Science:

• Environmental Science
• Biochemistry
• Toxicology

Background:

• Identifying endocrine disruptors (EDs) is crucial for public health.
• Existing screening methods require improvement for efficiency and cost-effectiveness.

Purpose of the Study:

• To develop and validate a novel in vitro screening assay for detecting endocrine-disrupting chemicals (EDCs).
• To identify structural characteristics of compounds exhibiting estrogenic activity.

Main Methods:

• Utilized a yeast two-hybrid system to detect ligand-dependent protein interactions.
• Measured hormonal activity via beta-galactosidase reporter gene expression.
• Screened over 500 chemical compounds for estrogenic activity.

Main Results:

• The developed assay demonstrated high repeatability for detecting agonists and was applicable to antagonists and metabolites.
• Sixty-four out of 500+ tested chemicals showed positive estrogenic activity.
• A common structural feature of positive compounds was identified: a phenol with a para-positioned hydrophobic moiety and no ortho-positioned bulky groups.

Conclusions:

• The yeast two-hybrid assay is a simple, inexpensive, and reliable tool for primary screening of potential endocrine disruptors.
• The identified structural features can guide further risk assessment and the design of safer chemicals.
• This method has been adopted by over 40 laboratories in Japan, highlighting its utility and applicability.