Mapping of the hSOX10 protein interactome in human melanoma

Abstract

The transcription factor SOX10 is a central regulator of melanoma biology, influencing tumor initiation, progression, phenotypic plasticity, and therapeutic resistance. However, the molecular mechanisms underlying these diverse functions remain incompletely understood. To elucidate the protein-protein interactions (PPIs) that mediate SOX10 activity in melanoma, we mapped the human SOX10 (hSOX10) interactome for the first time in human melanoma cells (A375 line). Given the challenges of capturing transient and weak transcription factor interactions, we employed miniTurbo (mT) proximity-dependent biotinylation coupled with mass spectrometry (MS). Stable A375 cell lines expressing N- and C-terminal mT-tagged hSOX10 fusion proteins at physiologically relevant levels were generated, enabling unbiased biotinylation and MS-based identification of candidate interacting proteins. This approach revealed 847 melanoma-enriched candidate interactors, including 213 high-confidence hits. These included both known hSOX10 partners and previously unidentified putative interactors. Functional annotation of our hSOX10 interactome highlighted associations with chromatin remodeling, transcriptional regulation, SUMOylation, and DNA damage response pathways. Western blot validation of select interactors supported the robustness of our dataset. This first comprehensive map of the hSOX10 interactome in melanoma provides a critical foundation for future investigations into SOX10-driven transcriptional networks and their potential as therapeutic targets and biomarkers in melanoma.