Activation of the archaeal ion channel MthK is exquisitely regulated by temperature.

ABSTRACT: Physiological response to thermal stimuli in mammals is mediated by a structurally diverse class of ion channels, many of which exhibit polymodal behavior. To probe the diversity of biophysical mechanisms of temperature-sensitivity, we characterized the temperature-dependent activation of MthK, a two transmembrane calcium-activated potassium channel from thermophilic archaebacteria. Our functional complementation studies show that these channels are more efficient at rescuing K⁺ transport at 37°C than at 24°C. Electrophysiological activity of the purified MthK is extremely sensitive (Q₁₀ >100) to heating particularly at low-calcium concentrations whereas channels lacking the calcium-sensing RCK domain are practically insensitive. By analyzing single-channel activities

SUBMITTER: Jiang Y 

PROVIDER: S-EPMC7717905 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature