Gating the pore of the calcium-activated chloride channel TMEM16A

Andy K. M. Lam*, Jan Rheinberger, Cristina Paulino*, Raimund Dutzler*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

3 Citaten (Scopus)
12 Downloads (Pure)

Samenvatting

The binding of cytoplasmic Ca2+ to the anion-selective channel TMEM16A triggers a conformational change around its binding site that is coupled to the release of a gate at the constricted neck of an hourglass-shaped pore. By combining mutagenesis, electrophysiology, and cryo-electron microscopy, we identified three hydrophobic residues at the intracellular entrance of the neck as constituents of this gate. Mutation of each of these residues increases the potency of Ca2+ and results in pronounced basal activity. The structure of an activating mutant shows a conformational change of an α-helix that contributes to Ca2+ binding as a likely cause for the basal activity. Although not in physical contact, the three residues are functionally coupled to collectively contribute to the stabilization of the gate in the closed conformation of the pore, thus explaining the low open probability of the channel in the absence of Ca2+.

Originele taal-2English
Artikelnummer785
Aantal pagina's13
TijdschriftNature Communications
Volume12
Nummer van het tijdschrift1
DOI's
StatusPublished - 4-feb-2021

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