Phase Separation to Resolve Growth-Related Circuit Failures.

Area of Science:

• Synthetic biology
• Biochemistry
• Molecular engineering

Background:

• Host cell growth fluctuations challenge synthetic gene circuit stability and function.
• Current solutions for circuit stabilization often require complex redesign and lack broad applicability.

Purpose of the Study:

• To introduce a novel strategy for stabilizing synthetic gene circuits against host cell growth fluctuations.
• To leverage liquid-liquid phase separation (LLPS) as a mechanism for enhancing circuit robustness.

Main Methods:

• Engineering a self-activating synthetic gene circuit.
• Fusing transcription factors (TF) with intrinsically disordered regions (IDR) to promote condensate formation.
• Analyzing the impact of TF condensates on circuit performance and memory retention under varying growth conditions.

Main Results:

• Formation of transcription factor (TF) condensates at promoter regions was achieved via intrinsically disordered regions (IDR).
• Condensate formation successfully maintained local TF concentration, counteracting dilution effects from host cell growth.
• Bistable memory in the self-activating circuit was robustly preserved, demonstrating enhanced circuit stability.

Conclusions:

• Liquid-liquid phase separation (LLPS) offers a broadly applicable design principle for creating resilient synthetic gene circuits.
• Engineered TF-IDR fusions provide a novel method to stabilize circuit function against dynamic cellular environments.
• This approach advances the development of robust synthetic biological systems for diverse applications.