A Prion Epigenetic Switch Establishes an Active Chromatin State

Area of Science:

• Epigenetics and Chromatin Biology
• Molecular Genetics
• Cellular Stress Response

Background:

• Histone modifications are crucial for establishing functional chromatin domains during development.
• Inheritance of repressed chromatin is well-understood, but mechanisms for activated chromatin inheritance are lacking.

Purpose of the Study:

• To investigate the mechanism behind the transgenerational inheritance of activated chromatin states.
• To identify factors that facilitate the inheritance of gene expression patterns.

Main Methods:

• Utilized yeast models to study histone modifications and chromatin states.
• Investigated the role of the Set3C histone deacetylase scaffold Snt1.
• Characterized a novel prion, termed [ESI+], and its impact on gene activation.

Main Results:

• Identified Snt1 as a prion that drives the emergence and inheritance of activated chromatin.
• Demonstrated that [ESI+] is triggered by Snt1 phosphorylation during cell cycle arrest.
• Showed that [ESI+] reshapes Snt1 activity, leading to gene activation and environmental stress resistance.

Conclusions:

• Established a novel prion-based mechanism for the inheritance of activated chromatin states.
• Highlighted the role of [ESI+] in providing adaptive benefits through transgenerational epigenetic inheritance.
• Opened new avenues for understanding epigenetic memory and its role in evolution.