Protein-DNA co-condensation is prewetting to a collapsed polymer

Area of Science:

• Biophysics
• Molecular Biology
• Genomics

Background:

• Chromatin's 3D organization influences gene expression.
• Nuclear proteins can phase separate, co-condensing with chromosomes in vivo.
• The interaction between DNA and protein phases is not fully understood.

Purpose of the Study:

• Investigate how DNA interacts with 3D protein phases.
• Explore novel phase transitions driven by polymer-protein interactions.
• Understand the role of chromatin in forming these phases.

Main Methods:

• Lattice Monte-Carlo simulations.
• Mean-field theory.
• Modeling polymer-protein mixtures.

Main Results:

• A compressible polymer coupled with protein mixtures can induce generalized prewetting transitions.
• Polymer collapse coincides with stabilized liquid droplets.
• These phases can be stable even when polymer collapse or liquid phases are unstable alone.
• Component concentration changes alter 3D polymer structure.

Conclusions:

• DNA acts as a surface for novel protein phase formation.
• These protein-DNA interactions are crucial for chromatin's role in gene regulation.
• The study reveals new mechanisms for chromatin organization and gene expression control.