Ingram et al. identify and characterize the membrane conductance properties of mouse cone photoreceptors, including the light-dependent conductance in the outer segment and voltage-dependent and Ca2+-activated conductances in the cone inner segment, which shape the voltage response to light.

Zhang et al. derivatize wheat germ agglutinin with small-molecule fluorescent pH sensors to visualize proton fluxes over the extracellular surfaces of transfected cells and primary cardiomyocytes and neuron–astrocyte cocultures.

The expression of expanded CUG-repeat RNAs in myotonic dystrophy type 1 patients is associated with cardiac electrophysiological defects and an elevated risk of sudden cardiac death. Tylock et al. reveal that expression of these RNAs in the murine heart results in prolonged QRS and corrected QT-intervals due to alterations in sodium and potassium channel activity.

Neuronal ASIC channels mediate excitatory sodium currents in response to extracellular acidification. Lynagh et al. reveal the essential roles of pore-lining glutamates in ion conduction and selectivity for ASIC1a- and ASIC2a-containing channels.

Mammalian isoforms of mitochondrial VDAC have unique functional roles in vivo, but they all share similar β-barrel pore structures. Queralt-Martín et al. provide the first mechanistic insights into VDAC’s isoform-specific function by showing that VDAC3 exhibits unique properties when interacting with cytosolic proteins α-synuclein and tubulin.

Bohannon et al. show that polyunsaturated fatty acids (PUFAs) vary in their ability to activate cardiac IKs potassium channels depending on the pKa of the PUFA head group, allowing PUFAs to be tuned to treat long QT syndrome mutants with different disease severity.

The auxiliary proteins CaM and FHF bind to the C-terminal domain of voltage-gated sodium channels to limit the persistent inward currents associated with cardiac arrhythmias. Gade et al. reveal that CaM and FHF exert their effects by stabilizing an interaction between the channel’s C-terminal domain and III-IV linker region.