Chemoproteomics identifies Ykt6 as the direct target of schisandrin A for neuroprotection

Schisandrin A is a natural dibenzocyclooctene lignan with potent neuroprotective activity. However, the specific mechanisms or direct target proteins have not been clarified up to now. In this study, we designed and synthesized the probes of schisandrin A with photoreactive diazirine and clickable alkyne to identify its direct target in SH-SY5Y cells by employing activity-based protein profiling (ABPP) technique. Ykt6 was prominent among the 13 proteins obtained with high confidence and we confirmed Ykt6 as the direct target of schisandrin A by CETSA, IF, SPR and knockdown assay. Functionally, schisandrin A protected the cells against the injury induced by glutamate by regulating autophagy via Ykt6. This discovery may provide a novel therapeutic option for various neuronal cell damage-mediated diseases.