GATA3 differentially regulates the transcriptome via zinc finger 2-modulated phase separation.

Area of Science:

• Molecular Biology
• Genetics
• Cancer Biology

Background:

• Phase separation (PS) is crucial for gene regulation by transcription factors.
• The role of DNA-binding domains (DBDs) in modulating transcription factor PS and its impact on differential gene regulation remains largely unexplored.

Purpose of the Study:

• To investigate how DNA-binding domains (DBDs) regulate the phase separation (PS) of transcription factors.
• To elucidate the mechanism by which GATA3's DBD modulates PS and its implications in breast cancer.

Main Methods:

• Investigated GATA3 phase separation and chromatin condensate formation.
• Analyzed the role of the zinc finger 2 (ZnF2) domain and specific arginine residues (R329, R330) in GATA3 PS.
• Compared the effects of wild-type and mutated GATA3 (ZnF2-defective) on transcriptome regulation and tumor growth in mice.

Main Results:

• GATA3 undergoes DNA-binding domain (DBD)-modulated phase separation (PS) to form chromatin condensates.
• The zinc finger 2 (ZnF2) domain of GATA3, through positive charges from R329 and R330, drives PS via electrostatic interactions.
• ZnF2-defective GATA3 mutations in breast cancer lead to aberrant PS, altered transcriptome regulation, favorable prognosis, and reduced tumor growth in mice.

Conclusions:

• Transcription factor DBDs play a critical role in modulating phase separation for differential gene regulation.
• GATA3's DBD-modulated PS is a key mechanism for controlling the transcriptome.
• Aberrant GATA3 PS due to mutations has significant implications for breast cancer progression and patient outcomes.