Bifurcations and multistability in inducible three-gene toggle switch networks

Area of Science:

• Systems Biology
• Molecular Biology
• Biophysics

Background:

• Gene regulatory circuits control essential biological processes.
• Multistability in two- and three-gene networks is crucial for development and metabolism.
• Theoretical models often lack biological specificity in parameter control.

Purpose of the Study:

• To investigate the role of effector molecules in controlling transcription factor concentrations.
• To extend bistable switch models to three-gene networks using allosteric regulation.
• To analyze multistable dynamics as a function of effector concentrations and regulatory mechanisms.

Main Methods:

• Modeling allosteric regulation in three-gene networks.
• Analyzing dynamics under varying regulatory circuit mechanics and inducer activity.
• Investigating effector control mechanisms for dual-function proteins.

Main Results:

• Effector molecules significantly influence multistable dynamics in gene regulatory circuits.
• The biological mechanism of effector control alters phenotypic trends and available dynamic regimes.
• Key parameters and regulatory features driving phenotypic decisions were identified.

Conclusions:

• Allosteric regulation by effector molecules provides a tunable mechanism for encoding inducible multistable behavior.
• This framework applies to both single- and dual-function allosteric transcription factors.
• The study offers an experimentally tractable system for understanding complex gene regulation.