Growth Feedback Confers Cooperativity in Resource-Competing Synthetic Gene Circuits.

Area of Science:

• Synthetic biology
• Systems biology
• Biophysics

Background:

• Modularity is crucial for synthetic gene circuit design, enabling complex systems from basic parts.
• Challenges arise when modular components fail in larger circuits due to issues like resource competition and growth feedback.
• The interplay between resource competition and growth feedback in gene circuit dynamics is not fully understood.

Purpose of the Study:

• To develop a theoretical framework for analyzing synthetic gene circuit dynamics.
• To investigate the combined effects of resource competition and growth feedback.
• To understand how these factors influence host-circuit interactions and gene expression.

Main Methods:

• Theoretical modeling of synthetic gene circuit dynamics.
• Analysis of resource competition among genes.
• Incorporation of growth feedback mechanisms into the model.

Main Results:

• Resource-competing synthetic gene circuits exhibit cooperative behavior under growth feedback.
• Cooperation or competition is non-monotonically determined by the metabolic burden threshold.
• Growth feedback can attenuate winner-takes-all resource competition, influencing circuit activation/deactivation.

Conclusions:

• Coupling growth feedback and resource competition is vital for host-circuit system dynamics.
• Understanding these intertwined effects aids in controlling unexpected gene expression.
• This framework provides insights into designing more predictable synthetic gene circuits.