Ligand-Directed Self-Assembling Chimeras for Targeted Protein O-GlcNAcylation

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Protein O-GlcNAcylation is crucial for cellular signaling but difficult to control precisely.
• Existing methods for targeted O-GlcNAcylation are limited by the lack of suitable O-GlcNAc transferase (OGT) ligands.
• Chemically induced proximity (CIP) is a promising approach for targeted protein modification.

Purpose of the Study:

• To develop a novel method for precise, protein-specific O-GlcNAcylation control in living cells.
• To create a non-inhibitory covalent probe for OGT using ligand-directed release (LDR) chemistry.
• To engineer a self-assembling O-GlcNAcylation Targeting Chimera (OGTAC) for targeted OGT recruitment.

Main Methods:

• Repurposing a potent OGT inhibitor into a non-inhibitory covalent probe via LDR chemistry.
• Designing and constructing a self-assembling OGTAC scaffold.
• Applying the OGTAC in living cells to target casein kinase IIα (CK2α) for O-GlcNAcylation.

Main Results:

• Developed novel ligands that covalently label OGT while preserving its enzymatic activity.
• Successfully engineered a self-assembling OGTAC that recruits OGT to its native substrate CK2α.
• Achieved selective elevation of CK2α O-GlcNAcylation in cells without impacting global modification levels.

Conclusions:

• Introduced a new class of self-assembling chimeras for covalent OGT engagement and protein-specific O-GlcNAcylation.
• Demonstrated a versatile platform for dissecting and controlling O-GlcNAc signaling in living systems.
• Paved the way for next-generation OGTACs and therapeutic strategies targeting O-GlcNAc modulation.