CAGE-prox: A Unified Approach for Time-Resolved Protein Activation in Living Systems

Jie Wang1,2, Yuan Liu1, Yanjun Liu1

  • 1Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.

Current Protocols
|June 24, 2021
PubMed

Insights

A new method called CAGE-prox enables precise temporal control over protein activity in living systems. This computationally designed approach uses caged amino acids to reversibly block protein function until photoactivated.

Area of Science:

  • Molecular Biology
  • Biochemistry
  • Chemical Biology

Background:

  • Temporal activation of proteins of interest (POIs) is crucial for studying dynamic biological processes using gain-of-function approaches.
  • Existing methods like protein fusion or active site decaging have limitations in generality or introduce bulky tags.
  • There is a need for versatile and non-disruptive methods for time-resolved protein activation.

Purpose of the Study:

  • To introduce and validate the computationally aided and genetically encoded proximal decaging (CAGE-prox) strategy.
  • To demonstrate CAGE-prox's utility for time-resolved photoactivation of a broad range of proteins.
  • To provide a computational framework for optimizing caged amino acid insertion sites.

Main Methods:

  • Development of a computational algorithm to identify optimal sites for caged unnatural amino acid insertion near a protein's functional site.
  • Genetic encoding of caged amino acids for proximity-based protein activity blockade.
  • Photo/chemical decaging for temporal rescue and activation of protein function.
  • Experimental validation of the CAGE-prox strategy across various applications.

Main Results:

  • The CAGE-prox strategy enables effective temporal blockade and photo-induced reactivation of protein activity.
  • Computational screening successfully identified optimal insertion sites for caged amino acids.
  • Demonstrated orthogonal activation of POIs, minimizing interference from endogenous proteins.
  • Applied CAGE-prox to time-resolved proteomics and controlled activation of protein-based prodrugs.

Conclusions:

  • CAGE-prox offers a general, non-disruptive, and computationally guided approach for precise temporal control of protein function in living systems.
  • This strategy facilitates gain-of-function studies and novel therapeutic applications.
  • CAGE-prox represents a significant advancement in optogenetic and chemogenetic tools for biological research.