English

Condensation and activator/repressor control of a transcription-regulated biomolecular liquid

Soft Condensed Matter 2024-10-30 v1 Biological Physics

Abstract

Cells operate in part by compartmentalizing chemical reactions. For example, recent work has shown that chromatin, the material that contains the cell's genome, can auto-regulate its structure by utilizing reaction products (proteins, RNA) to compartmentalize biomolecules via liquid-liquid phase separation (LLPS). Here, we develop a model biomolecular system that permits quantitative investigation of such dynamics, particularly by coupling a phase-separating system of DNA nanostars to an in vitro transcription reaction. The DNA nanostars' sequence is designed such that they self-assemble into liquid droplets only in the presence of a transcribed single-stranded RNA linker. We find that nanostar droplets form with a substantial delay and non-linear response to the kinetics of RNA synthesis. In addition, we utilize the compartments generated by the phase-separation process to engineer an activator/repressor network, where the transcription reaction activates the formation of droplets, and then droplets suppress the transcription reaction by segregating transcription components inside them. Our work on transcription-driven liquid-liquid phase separation constitutes a robust and programmable platform to explore non-equilibrium reaction-phase transition dynamics and could also provide a foundation to understand the dynamics of transcriptional condensate assembly in cells.

Keywords

Cite

@article{arxiv.2410.21624,
  title  = {Condensation and activator/repressor control of a transcription-regulated biomolecular liquid},
  author = {Sam Wilken and Gabrielle R. Abraham and Omar A. Saleh},
  journal= {arXiv preprint arXiv:2410.21624},
  year   = {2024}
}