- The α2δ-1 subunit remodels CaV1.2 voltage sensors
Voltage-sensing domains (VSDs) in voltage-gated calcium channels sense the potential difference across membranes and interact with the pore to open it. Savalli et al. find that the accessory subunit α2δ-1 increases the sensitivity of VSDs I–III and also their efficiency of coupling to the pore.
- Ion channel coupling in epithelial ion transport
Principal cells regulate the ionic environment of the epididymal lumen via unknown mechanisms. Gao et al. use electrophysiological and pharmacological tools to characterize rat principal cells and reveal a TRPV6-mediated calcium conductance and TMEM16A-mediated calcium-activated chloride conductance.
- Conformational heterogeneity of KcsA in bicelles
KcsA is a potassium channel that is gated open and closed by changes in pH. Kim et al. find that at least two conformational states exist for both closed and open KcsA channels using solution NMR.
- AmCaV4 channel characterization
Insect DSC1 channels have sequences that are intermediate between voltage-gated Na+ and Ca2+ channels but have hitherto been classified as the former. Gosselin-Badaroudine et al. clone and characterize honeybee DSC1, revealing high selectivity for Ca2+ and suggesting reclassification of DSC1 homologues as Ca2+ channels.
- Mechanism of AChR activation
Mukhtasimova et al. describe experimental modifications of the patch clamp technique that improve temporal resolution of currents through single acetylcholine receptor channels. The study not only distinguishes between the priming and gating steps, but it also reveals how rate and equilibrium constants change as a function of agonist occupancy.