Cloxyquin activates hTRESK by allosteric modulation of the selectivity filter

Area of Science:

• Molecular biology
• Neuroscience
• Immunology

Background:

• The TWIK-related spinal cord K+ channel (TRESK) maintains cell membrane potentials.
• TRESK plays a crucial role in T-cell differentiation, making it a target for autoimmune disease treatments.
• Cloxyquin is a promising activator of TRESK and a potential immunomodulator.

Purpose of the Study:

• To identify the cloxyquin binding site on the TRESK channel.
• To elucidate the molecular mechanism by which cloxyquin activates TRESK.
• To provide a basis for developing novel immunomodulatory drugs.

Main Methods:

• Mutational scan to identify the cloxyquin binding site.
• Protein modeling and in silico electrophysiology.
• In vitro electrophysiology using K+ and Rb+.
• Kinetic analyses of channel inactivation.

Main Results:

• The cloxyquin binding site was identified at the M2/M4 interface of the TRESK channel.
• Cloxyquin allosterically stabilizes the inner selectivity filter.
• This stabilization facilitates ion conduction and activates the human TRESK (hTRESK) channel.

Conclusions:

• Cloxyquin activates hTRESK by stabilizing the inner selectivity filter at the M2/M4 interface.
• The findings provide a molecular understanding of TRESK activation by cloxyquin.
• This research paves the way for developing cloxyquin-based therapeutics for autoimmune conditions.