Confirmation of trans -auto- S -acylation in peripheral cysteines on a catalytically dead C-HA-ZDHHC20(C156S) (D) by a mutant C-FLAG-ZDHHC20(Y181G) (M) with 15 M 18-Bz. Catalytically dead C-FLAG-ZDHHC20(Y181G) (DM) did not transfer the probe to D. Cells transfected with an empty vector (E) were used as negative control. HA- and FLAG-tagged ZDHHC20 constructs were transiently cotransfected into HEK293T cells and treated with 15 M 18-Bz for 4 h. After cell lysis, constructs were separately enriched on anti-HA and anti-FLAG resins, clicked with TAMRA-azide and separated by SDS–PAGE. Loading and input were visualized by in-gel fluorescence and immunoblot, respectively. The average ( n = 3 independent biological replicates) loading and transfer activity were reported as a percent of the maximal fluorescent:input ratios s.d. a , c , f , The two-tailed unpaired t test of Prism 9.0 was used to determine P values and noted above relevant comparisons.
