Genetic encoding of ε- N -L-lactyllysine for detecting delactylase activity in living cells.

Lysine ε- N -L-lactylation is a newly discovered post-translational modification. Herein we present the genetic encoding of ε- N -L-lactyllysine in bacterial and mammalian cells, allowing the preparation of site-specifically ε- N -L-lactylated recombinant proteins and the construction of fluorescent and luminescent probes for detecting delactylases in living cells. Using these probes, we demonstrate sirtuin 1 as a potential delactylase for non-histone proteins.