Split-luciferase complementation assay to detect channel–protein interactions in live cells

The understanding of ion channel function continues to be a significant driver in molecular pharmacology. In this field of study, protein-protein interactions are emerging as fundamental molecular determinants of ion channel function and as such are becoming an attractive source of highly specific targets for drug development. The investigation of ion channel macromolecular complexes, however, still relies on conventional methods that are usually technically challenging and time-consuming, significantly hampering our ability to identify, characterize and modify ion channel function through targeted molecular approaches. As a response to the urgent need of developing rapid and albeit accurate technologies to survey ion channel molecular complexes, we describe a new application of the split-luciferase complementation assay to study the interaction of the voltage-gated Na + channel with the intracellular fibroblast growth factor 14 and its dynamic regulation in live cells. We envision that the flexibility and accessibility of this assay will have a broad impact in the ion channel field complementing structural and functional studies, enabling the interrogation of protein–channel dynamic interactions in complex cellular contexts and laying the basis for new frameworks in drug discovery campaigns.