It is controversial whether the cardiac type-2 ryanodine receptor harboring a catecholaminergic polymorphic ventricular tachycardia-associated point mutation is regulated by luminal or cytosolic Ca²⁺. This commentary discusses new findings supporting the cytosolic Ca²⁺-dependent regulation.

Young et al. review and synthesize the mechanistic principles of forces and energies involved in Piezo ion channel mechanotransduction.

Phosphoinositides, rare membrane lipids, mediate powerful second messenger signals to ion channels, endocytosis, and exocytosis, and specify organelle identity. Jensen et al. summarize 20 yr of biophysical research whose key message is that pools of phosphoinositides turn over remarkably quickly to regulate rapid physiological responses.