Orthogonal IMiD-Degron Pairs Induce Selective Protein Degradation in Cells

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Immunomodulatory imide drugs (IMiDs) facilitate targeted protein degradation via zinc finger (ZF) degron motifs.
• Existing IMiDs can degrade unintended cellular proteins, such as IKZF1 and IKZF3, limiting their specificity.

Purpose of the Study:

• To engineer a highly selective protein degradation system by designing novel IMiD analogs.
• To overcome the lack of specificity associated with current IMiD-based protein degradation strategies.

Main Methods:

• Employed a "bump-and-hole" strategy to create mutated ZF proteins and corresponding IMiD analogs.
• Screened 8380 ZF mutants against bumped IMiD analogs to identify selective interactions.
• Validated the system's efficacy in degrading TRIM28, a disease-relevant protein.

Main Results:

• Developed a novel IMiD analog that selectively degrades a mutated ZF degron.
• Demonstrated that the new system does not induce degradation of endogenous proteins like IKZF1 and IKZF3.
• Successfully applied the system for targeted degradation of TRIM28 in proof-of-concept studies.

Conclusions:

• The developed "bump-and-hole" IMiD system offers enhanced selectivity for targeted protein degradation.
• This technology provides a valuable tool for protein knockdown in target validation and potentially therapeutic applications.
• The system enables degradation of proteins lacking known small molecule binders, expanding the scope of targeted protein degradation.