Phosphatidylinositol 4,5-bisphosphate is regenerated by speeding of the PI 4-kinase pathway during long PLC activation
Stimulation of muscarinic Gq-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.
Different arrhythmia-associated calmodulin mutations have distinct effects on cardiac SK channel regulation
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.
Resting and stimulated mouse rod photoreceptors show distinct patterns of vesicle release at ribbon synapses
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.
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