G-Quadruplex-Induced Liquid-Liquid Phase Separation in Biomimetic Protocells

Area of Science:

• Molecular Biology
• Biophysics
• Cell Biology

Background:

• Biomolecular condensates are crucial for organizing eukaryotic cells.
• The role of nucleic acid structure in phase separation remains unclear.

Purpose of the Study:

• To investigate the role of single-stranded DNA (ssDNA) secondary structure in biomolecular phase separation.
• To explore the formation of condensates within a protocell model.

Main Methods:

• Utilized giant membrane vesicles (GMVs) as a protocell model.
• Investigated the interaction between G-quadruplex structured ssDNA and G-quadruplex-binding proteins.

Main Results:

• ssDNA with parallel G-quadruplex structures functionally cooperated with proteins to form speckle-like puncta within GMVs.
• Condensate formation depended on G-quadruplex structural diversity.
• Observed reversible clustering, suggesting a dynamic regulation pathway for biomolecular condensates.

Conclusions:

• Established a link between G-quadruplex-binding proteins and G-quadruplex-mediated biomolecular phase separation.
• Findings provide insights into nucleic acid-modulated phase separation in biological processes.