Mining the CRBN target space redefines rules for molecular glue-induced neosubstrate recognition

Area of Science:

• Molecular biology and pharmacology
• Protein degradation pathways
• Drug discovery and development

Background:

• The CRL4^CRBN E3 ubiquitin ligase is a key target for molecular glue degraders.
• These compounds reprogram ligase specificity to induce degradation of neosubstrate proteins.
• Existing cereblon (CRBN) neosubstrates share a β-hairpin G-loop recognition motif.

Purpose of the Study:

• To systematically explore the CRBN target space beyond known motifs.
• To identify novel neosubstrates and binding mechanisms for CRL4^CRBN.
• To establish a platform for developing next-generation molecular glue degraders.

Main Methods:

• Utilized computational mining with structure- and surface-based matchmaking algorithms.
• Analyzed protein structures to identify CRBN-compatible G-loop proteins.
• Investigated noncanonical binding modes, such as VAV1's molecular surface mimicry.

Main Results:

• Predicted over 1600 CRBN-compatible G-loop proteins in the human proteome.
• Discovered a novel helical G-loop motif for CRBN recognition.
• Identified VAV1 as a noncanonical neosubstrate with a unique binding mechanism.

Conclusions:

• Broadened the understanding of the CRBN target space and neosubstrate recognition rules.
• Demonstrated the potential for repurposing CRL4^CRBN to target challenging proteins.
• Established a foundation for developing advanced molecular glue degraders for drug discovery.