Comprehensive Proteomic Profiling of Human Nav1.7-Interacting Proteins Reveals Conserved Regulatory Networks Involved in Nociceptive Signaling.

The voltage-gated sodium channel Nav1.7, encoded by the SCN9A gene, is critically involved in the initiation and propagation of nociceptive signals. While prior research has delineated the interactome of mouse Nav1.7 (mNav1.7), the molecular partners associated with its human homolog (hNav1.7) remain largely undefined. In this study, we employed tandem affinity purification (TAP) combined with high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) to systematically characterize the protein-protein interaction (PPI) network of hNav1.7 in stably transfected HEK293 cells. Functional expression of TAP-tagged hNav1.7 was confirmed by immunofluorescence, immunoblotting, and whole-cell patch-clamp electrophysiology. A total of 261 interacting proteins were identified, primarily localized to the plasma membrane and cytoplasm, and predominantly enriched in protein translation, folding, and trafficking pathways. Comparative proteomic analysis revealed conserved interactors shared between human and mouse Nav1.7, including translation elongation factors (Eef1a1, Eef2), chaperonin subunits (CCT2, CCT3, CCT5, CCT6A, CCT7), and members of the kinesin and Rab GTPase families. Knockdown of 2 conserved interactors, CCT5 and TMED10, significantly reduced hNav1.7 current density, confirming their functional relevance. These findings provide new insights into the proteomic architecture and regulatory mechanisms of hNav1.7, offering potential targets for modulating channel function in pain pathophysiology.