In this review, Nathan et al. discuss recent structural insights into the regulation of the Na+ channels NaV1.5 and NaV1.4, facilitated by the combination of cryo-EM and x-ray crystallography data.
External Cd2+ and protons activate the hyperpolarization-gated K+ channel KAT1 at the voltage sensor
Zhou et al. show that the hyperpolarization-gated K+ channel KAT1 shares a homologous divalent cation/proton binding pocket in the external voltage sensor with depolarization-gated EAG family K+ channels. Divalent ions/protons inhibit EAG channels but potentiate activation of KAT1.
Meizoso-Huesca and Launikonis describe multiple effects of BTP2, an inhibitor of the Ca2+ channel Orai1, on Ca2+ handling in skeletal muscle, which include impairment of Ca2+ release from the sarcoplasmic reticulum and indirect effects on the activity of the ryanodine receptors.
Large transient capacitive currents in wild-type lysosomal Cl−/H+ antiporter ClC-7 and residual transport activity in the proton glutamate mutant E312A
Pusch and Zifarelli show that the lysosomal 2 Cl−/1 H+ antiporter ClC-7 mediates large, transient capacitive currents, which depend on external pH and internal Cl−. Unlike in other mammalian CLC antiporters, mutation of a conserved proton glutamate residue in ClC-7 does not abolish transport currents.
Methods and Approaches
Mashanov et al. present a method to image and track individual fluorescently labeled molecules in live cardiac tissue slices using total internal reflection fluorescence (TIRF) microscopy. They show that the movement and interaction of G protein–coupled receptors can be observed in real time.