Clustering Dynamically Modulate the Biophysics of Voltage-Gated Sodium Channels: How Nanoscale Phenomena Determine Health and Disease

Precise regulation of ion channel biophysics is an essential life process that governs electrical signaling in excitable tissues. Many ion channels including voltage-gated Na ⁺ channels (Na _V s) exist in the membrane as clusters, which show distinct biophysical behavior not predicted by single-channel measurements. In both heterologous and native systems, we report that single-channel-based predictions significantly overestimated Na ⁺ current (I _Na ) amplitudes from multi-channel clusters. Computational modeling suggested that these observations could reflect interactions between adjacent channels, such as recently reported between Na _V s, and identified specific biophysical consequences thereof. This updated model not only accurately predicted behaviors observed from Na _V clusters and consequent cellular physiology, but also suggested the possibility that clustered Na _V s may respond differently to use-dependent pharmacological agents. Experiments validated the latter prediction and further identified modulation of clustering as a novel approach to correcting macroscopic electrophysiological dysfunction resulting from Na _V defects linked to life-threatening arrhythmias and seizures. Thus, our study not only motivates a fundamental revision of how ion channels behave when clustered but also highlights resulting biophysical effects as important considerations for pharmacology and a potential therapeutic target to address human disease.