Sewanan et al. studied a mutation to cardiac tropomyosin that causes hypertrophic cardiomyopathy. Computational models, in vitro experiments, and patient-specific engineered heart tissues suggest that this mutation triggers hypertrophy by allowing excess residual contractile activity.

Ahern et al. show that the absence of Rad increases peak L-type calcium influx independently of β-adrenergic receptor signaling. This increased peak current is homeostatically balanced by channel inactivation, allowing enhanced contraction without action potential prolongation. The loss of Rad is a potential therapeutic target for safe positive inotropic support.

Moise et al. develop a finite element model of the intercalated disk (ID) that takes into account the nanoscale structure. Incorporating these details in a cardiac tissue model predicts that alterations in ID structure can affect electrical conduction in the heart.

Lopez-Redondo et al. use cryo-EM and molecular dynamics to evaluate the effects of Zn2+ binding on the conformation and dynamics of the zinc/proton antiporter YiiP. Removal of Zn2+ leads to enhanced conformational dynamics and causes a transition to an intermediate state in the transport cycle.

Zhao et al. leverage the analysis of local conformational changes in a mutant Hv1 channel to inform the design of new inhibitors. These arginine mimics have improved interaction with the voltage-sensing domain and inhibit the wild-type channel with higher strength than guanidine derivatives.

Zhao and colleagues use the Hv1 channel to study drugs that modulate channel activity by binding to the voltage-sensing domain (VSD). They describe a new compound that interacts with a known and a new site in distinct conformations and thus suggests new strategies to identify VSD-binding compounds.

Han et al. study the effect of primary cardiac hypertrophy on cardiac mechano-energetics. Using isolated cardiac tissues, they show that despite impaired contractile performance, cardiac mechanical efficiency is preserved in hypertrophic hearts.