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.

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.

This review focuses on thin filament regulatory mechanisms with emphasis on cardiac-specific mechanisms in the three-state model of sarcomere activation and on signaling cascades at the barbed and pointed ends.