DHHC protein acyl transferase substrate identification by SILAC quantitative proteomics. (A) Knockout and wild type ZDHHC5 neuronal stem cells were grown in heavy and light SILAC media, and metabolically labeled with 17-ODYA. Cells were mixed with either light (wt) / heavy (ko) or light (ko) / heavy (wt) in 1:1 ratios for click chemistry, enrichment, and quantitative LC-MS analysis(31). (B) DHHC5 has distinct regulatory roles in neurons and neuronal stem cells. Flotillin2 is palmitoylated by DHHC5, leading to oligomerization and microdomain localization(31). EGF and FGF signaling are required for DHHC5 stabilization(31), likely mediated by multiple C-terminal sites of phosphorylation(75). In the absence of growth factors, DHHC5 is rapidly degraded by the proteasome(31). DHHC5 knockout neuronal stem cells fail to differentiate to neurons in culture(31). The C-terminal PDZ-binding motif of DHHC5 facilitates interactions with GRIP1b and PSD-95(47, 74). GRIP1b is palmitoylated by DHHC5, which contributes to effective activity-dependent AMPA receptor recycling(74).