PT  - JOURNAL ARTICLE
AU  - Lavanya Moparthi
AU  - Satish Babu Moparthi
AU  - Jérôme Wenger
AU  - Peter M. Zygmunt
TI  - Calcium activates purified human TRPA1 with and without its N-terminal ankyrin repeat domain in the absence of calmodulin
AID  - 10.1101/2020.03.19.999276
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.03.19.999276
4099  - http://biorxiv.org/content/early/2020/03/20/2020.03.19.999276.short
4100  - http://biorxiv.org/content/early/2020/03/20/2020.03.19.999276.full
AB  - Extracellular influx of calcium or release of calcium from intracellular stores have been shown to activate mammalian TRPA1 as well as to sensitize and desensitize TRPA1 electrophilic activation. Calcium binding sites on both intracellular N- and C-termini have been proposed. Here, we demonstrate based on fluorescence correlation spectroscopy (FCS), Förster resonance energy transfer (FRET) and bilayer patch-clamp studies, a direct calmodulin-independent action of calcium on the purified human TRPA1 (hTRPA1), causing structural changes and activation of hTRPA1 with and without its N-terminal ankyrin repeat domain (N-ARD). Thus, calcium can activate hTRPA1 by direct interaction with binding sites outside the N-ARD.