Kir4.1/Kir5.1 channels possess strong intrinsic inward rectification determined by a voltage-dependent K+-flux gating mechanism
Inward rectification of Kir channels is attributed to a voltage-dependent block of the channel pore by intracellular cations. Marmolejo-Murillo et al. identify a new intrinsic gating mechanism powered by the K+-flux in Kir4.1/Kir5.1 channels, which induces voltage-dependent inward rectification.
Recordings from neuron–HEK cell cocultures reveal the determinants of miniature excitatory postsynaptic currents
Chiang et al. recorded spontaneous miniature excitatory postsynaptic currents in cocultures of neurons and HEK cells. They show that this system allows the resolution of the distinct contributions of vesicles, fusion pores, dendrites, and receptors to the dynamic control of synaptic transmission.
Pore-forming transmembrane domains control ion selectivity and selectivity filter conformation in the KirBac1.1 potassium channel
Matamoros and Nichols show that mutations in a transmembrane domain outside of the selectivity filter of the KirBac1.1 K+ channel affect ion transport, suggesting that channel selectivity is determined by the physical interaction between different domains.
Cannabidiol inhibits the skeletal muscle Nav1.4 by blocking its pore and by altering membrane elasticity
Ghovanloo et al. combined in silico and in vitro approaches to determine the mechanism by which CBD inhibits the skeletal muscle Na+ channel Nav1.4. Their findings suggest that CBD acts directly, by binding inside the Nav1.4 pore, as well as indirectly, by modulating membrane elasticity.
Mechanical dysfunction of the sarcomere induced by a pathogenic mutation in troponin T drives cellular adaptation
Clippinger et al. examine a mutation in troponin T that causes hypertrophic cardiomyopathy and demonstrate that increased molecular mechanics drive the early disease pathogenesis, leading to secondary activation of mechanobiological signaling pathways.
An arginine residue in the outer segment of hASIC1a TM1 affects both proton affinity and channel desensitization
Acid-sensing ion channels (ASIC) play central roles in the central and peripheral nervous systems. In this paper, Chen et al. show that changes to a single arginine of a human ASIC both affect the efficacy of proton-mediated gating and delay the desensitization of the channel.
Mim et al. discuss discrepancies between the known functions of pannexin 1 as an ATP and chloride channel and recently published cryo-EM structural data, which so far appear consistent only with the chloride channel function.
This commentary analyzes the possible effects of lightness—a typical attribute of modern (liquid) society, according to Bauman—on the way we are doing science.
Fast inactivation of Nav1.3 channels by FGF14 proteins: An unconventional way to regulate the slow firing of adrenal chromaffin cells
Using Nav1.3 and FGF14 KO mice, Martinez-Espinosa et al. provide new findings on how intracellular FGF14 proteins interfere with the endogenous fast inactivation gating and regulate the “long-term inactivation” of Nav1.3 channels that sets Nav channel availability and spike adaptation during sustained stimulation in adrenal chromaffin cells.
JGP study demonstrates how recordings from neuron–HEK cell cocultures provide a clearer picture of the factors involved in synaptic transmission.