Issues

JGP study shows that small voltage changes disrupt semi-regular bursts of vesicle release from rod photoreceptors, potentially facilitating low-light vision.

New findings by Myeong et al. provide further details on how cells maintain their plasma membrane PI(4,5)P₂ levels when stimulated via M1 muscarinic receptors

Stimulation of muscarinic G_q-coupled receptors initially depletes phosphoinositide phosphatidylinositol 4,5-bisphosphate from the plasma membrane. Myeong et al. show that phosphoinositides subsequently regenerate during sustained receptor stimulation as a consequence of profound PI 4-kinase pathway acceleration and not desensitization of receptors.

Cardiac small-conductance Ca²⁺-activated K⁺ (SK) channels are gated solely by beat-to-beat changes in intracellular Ca²⁺. Ledford et al. show distinct mechanisms by which human calmodulin mutants linked to sudden cardiac death regulate SK channels.

Hays et al. studied glutamate release to understand how light-evoked responses are encoded at rod ribbon synapses. Individual vesicles fused stochastically in hyperpolarized rods, whereas release at depolarized potentials attained in darkness occurred in semiregular bursts of 10–20 vesicles.

Regulation of the Na/K pump is essential to maintain cells’ electrochemical gradients. Meyer et al. coexpressed the human α1β1 pump with five different FXYD proteins in Xenopus oocytes and show that FXYD isoforms have distinct effects on the pump’s ion affinity and membrane abundance.