Engineering Light-Responsive Transcription Factors via Strategic Masking of Post-translational Modification Residues

Area of Science:

• Synthetic biology
• Chemical biology
• Molecular biology

Background:

• Synthetic transcription factors (TFs) offer potential for controlling cellular processes.
• Mimicking post-translational modifications is key for advanced TF design.
• Existing methods face challenges in creating photoreactive proteins.

Purpose of the Study:

• To design and synthesize a novel caged TF variant with light-inducible activity.
• To demonstrate a strategy for creating photoreactive proteins using integrated synthesis techniques.
• To enable precise, on-demand control of TF DNA-binding activity.

Main Methods:

• Rational design of synthetic TFs with reversible modifications.
• Native chemical ligation (NCL) combined with palladium-mediated C-S cross-coupling.
• Synthesis of a caged Max variant with masked key residues (Lys31/57).

Main Results:

• Successfully synthesized a caged Max variant using a novel strategy.
• Engineered caged Max showed significantly reduced DNA-binding activity.
• Site-selective unmasking rapidly restored potent DNA-binding upon photolysis.
• On-demand activation of TF DNA-binding activity within minutes via photolysis.

Conclusions:

• Developed an effective method for producing and activating TF proteins.
• The caged Max variant provides precise, light-controlled modulation of DNA-binding.
• This approach enables the creation of light-responsive TF analogs for diverse applications.