Article
Remodeled connexin 43 hemichannels alter cardiac excitability and promote arrhythmias
This work demonstrates that the opening of lateralize cardiac connexin-43 hemichannels, in the absence of a cardiac pathology, is still sufficient to alter cardiac membrane excitability and promote arrhythmias upon β-adrenergic cardiac stress.
Molecular rearrangements in S6 during slow inactivation in Shaker-IR potassium channels
Szanto et al. provide data that support the idea that rearrangement of S6, including its rotation, may mediate the communication between the activation gate and the inactivation gate controlling slow inactivation in KV channels.
Communication
Physical activity impacts resting skeletal muscle myosin conformation and lowers its ATP consumption
Lewis et al. investigate how training status influences relaxed myosin conformations known to play a role in skeletal muscle metabolism. Their findings indicate that individuals with moderate activity levels have a shift in the relaxed conformations of their type II myosin molecules, lowering the basal ATP consumption.
Extracellular histone proteins activate P2XR7 channel current
Histone proteins are known to be elevated in circulation where they contribute to vascular dysfunction. However, many details regarding the mechanism of action are unknown. Here, the authors show that P2XR7 channel current is activated by extracellularly applied histone proteins in a heterologous expression system.
Commentary
Super relaxed myosins loosen up to different cues in cardiac and skeletal muscle sarcomeres
Recent papers by Nelson et al. and Pilagov et al. provide important new information on the ever-expanding role of myosin heads in the regulation of contraction.
