RNF213 is novel transthiolating E3 ligase that is activated by ATP. To determine whether cellular RNF213 is activated by elevated ATP levels, we electroplated an E3 activity-based probe into HEK293 cells stably expressing RNF213 in a knockout background. DIA analysis was performed in cells that were coelectroporated with the poorly hydrolysable ATP analog, ATPgS, or buffer control.