Class-Wide Analysis of Frizzled-Dishevelled Interactions Using BRET Biosensors Reveals Functional Differences among...

Area of Science:

• Cellular signaling pathways
• Molecular and structural biology

Background:

• Wingless/Int-1 (WNT) signaling is crucial for cellular processes, mediated by Frizzled (FZD) receptors binding WNT ligands.
• The interaction between FZDs and the signal transducer Dishevelled (DVL) is key, but FZD selectivity and paralog-specific differences remain unclear.

Purpose of the Study:

• To investigate the class-wide FZD/DVL interaction dynamics and ligand selectivity.
• To develop novel biosensors for high-throughput screening of FZD-targeted therapeutics.

Main Methods:

• Utilized bioluminescence resonance energy transfer (BRET) techniques with unimolecular FZD/DVL DEP domain sensors.
• Analyzed constitutive and ligand-stimulated FZD/DEP interactions across different FZD paralogs.

Main Results:

• Most Frizzleds exhibit a constitutive high-affinity interaction with the DVL DEP domain.
• Ligand stimulation revealed dynamic FZD/DEP interfaces with distinct paralog-specific profiles in ligand selectivity and signal kinetics.
• The developed unimolecular sensors are suitable for high-throughput screening.

Conclusions:

• Mechanistic differences in allosteric communication between FZDs and DVL were elucidated.
• The novel receptor-focused biosensors facilitate FZD-targeted drug discovery and development.