Affinity‐Based Protein Profiling Revealed that HIGD1A is a Direct Target Protein of Aristolochic Acids

Abstract Exposure to aristolochic acids (AA) via the ingestion of AA‐containing medicine or food is a significant risk factor for severe nephropathy. Despite decades of research, the direct molecular targets underlying AA toxicity remain elusive. In this study, a map of the AA‐binding protein atlas in kidney tissues is constructed via the design and synthesis of an AA‐based affinity probe. Among the AA‐binding proteins, HIGD1A is identified as a high‐affinity AA target (SPR: 59.6 n m ; ITC: 195 n m ) with significant thermostability changes upon AA binding. Furthermore, AA disrupted the HIGD1A‐TFAM interaction, triggering TFAM degradation via the autophagy‐lysosome pathway. This led to the accumulation of cytosolic mitochondrial DNA. This study also suggested that HIGD1A also contributed to AA‐induced inflammation by increasing the cytosolic levels of oxidized mitochondrial DNA to activate the MAPK and NF‐κB pathways. This study not only reveals an important target protein of AA but also provides novel inspiration and ideas for toxicology and chemical biology research.