Bioorthogonally Activatable Base Editing for On-Demand Pyroptosis.

Pyroptosis is an inflammatory cell death form triggered by protease-mediated truncation and release of the N-terminal pore-forming domain of the gasdermin (GSDM) family proteins in various cell types. We report a Bioorthogonally ACtivatable Base editor (BaseBAC) for in situ and on-demand initiation of cell-type-specific pyroptosis. We first made the enzymatic activity of a cytosine base editor (CBE) switchable by establishing a bioorthogonal blockage on the PAM-interacting residue to control its DNA-binding ability. The resulting BaseBAC allowed in situ control of base editing on the GSDME gene that switched to the truncated expression of its N-terminal domain to activate pyroptosis. BaseBAC offers a general method for on-demand awakening of functional domains of self-inhibiting proteins and the corresponding cellular processes with high specificity in living systems.