Small-Molecule Modulators of Lipid Raft Stability and Protein-Raft Partitioning

Area of Science:

• Biochemistry
• Cell Biology
• Biophysics

Background:

• Understanding membrane nanodomains, or lipid rafts, is limited by a lack of tools to manipulate their structure and protein interactions.
• Peripheral myelin protein 22 (PMP22) and MAL are key proteins associated with lipid rafts.

Purpose of the Study:

• To screen for small molecules that modulate the affinity of PMP22 for lipid rafts.
• To develop pharmacological tools for investigating lipid raft function and biophysics.

Main Methods:

• Screening of 24,000 small molecules for modulators of PMP22 raft affinity using giant plasma membrane vesicles (GPMVs).
• Counter-screening against MAL protein and assessing impact on raft formation.
• Testing compound effects on membrane fluidity and TRPM8 channel function in cells.

Main Results:

• Identified two classes of compounds modulating lipid raft formation and protein affinity.
• Class I compounds altered PMP22 and MAL raft affinity and reduced raft formation protein-dependently.
• Class II compounds modulated raft formation protein-independently, suggesting diverse stabilization forces.

Conclusions:

• Developed novel chemical tools for probing lipid raft biophysics and function.
• Demonstrated that distinct forces contribute to lipid raft stabilization.
• Showcased the compounds' ability to alter membrane fluidity and TRPM8 channel activity.