Similar voltage-sensor movement in spHCN channels can cause closing, opening, or inactivation
We show here that a similar voltage-sensor movement in mutant hyperpolarization-activated cyclic nucleotide-gated (HCN) channels can lead to more closing or more opening depending on the cAMP concentration, suggesting that voltage sensor-to-gate coupling is easily altered in HCN channels.
Mechanism of external K+ sensitivity of KCNQ1 channels
Occupation of the uppermost ion-binding site of the selectivity filter of K+ channels by external K+ promotes channel activity. Such a phenomenon is not observed in KCNQ1 voltage-gated channels, allowing a deeper understanding of their conduction and permeability mechanism.
A cooperative knock-on mechanism underpins Ca2+-selective cation permeation in TRPV channels
TRPV5 and TRPV6 are unique among TRP channels due to their high Ca2+ selectivity, while most other members of this ion channel family do not select for a specific cation type. Ives et al. used biomolecular simulations and in silico electrophysiology to determine the mechanism underlying this unusual Ca2+ selectivity.
Microscopic mechanism of PIEZO1 activation by pressure-induced membrane stretch
Membrane stretch activates mechanosensitive PIEZO1 channels, but how this stimulus modulates microscopic open and shut states to increase open probability is unknown. Here, Wijerathne et al. investigate this mechanism using single channel dwell time analysis and Markov-chain modeling.
Blockade of TRPV channels by intracellular spermine
This manuscript reports discovery of voltage-dependent inhibition of TRPV channels by intracellular polyamines and develops a kinetic model of this process. Polyamines are inhibitors of each TRPV sub-type.
Differential regulation of cardiac sodium channels by intracellular fibroblast growth factors
Intracellular fibroblast growth factors (iFGF) regulate voltage-gated sodium (NaV) channel expression and gating. Using a mouse model and heterologous expression in Xenopus oocytes, we describe mechanisms of how iFGF alters NaV channel activation and inactivation.
Sensing its own permeant ion: KCNQ1 channel inhibition by external K+
External potassium inhibits KCNQ1 channel through a mechanism involving increased occupancy of the filter S0 site by K+o.