Zinc activation of OTOP proton channels identifies structural elements of the gating apparatus.

ABSTRACT: Otopetrin proteins (OTOPs) form proton-selective ion channels that are expressed in diverse cell types where they mediate detection of acids or regulation of pH. In vertebrates there are three family members: OTOP1 is required for formation of otoconia in the vestibular system and it forms the receptor for sour taste, while the functions of OTOP2 and OTOP3 are not yet known. Importantly, the gating mechanisms of any of the OTOP channels are not well understood. Here, we show that zinc (Zn²⁺⁾, as well as other transition metals including copper (Cu²⁺), potently activates murine OTOP3 (mOTOP3). Zn²⁺ pre-exposure increases the magnitude of mOTOP3 currents to a subsequent acid stimulus by as much as 10-fold. In contrast, mOTOP2 currents are insensitive to activ

SUBMITTER: Teng B 

PROVIDER: S-EPMC10101688 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature