 The reverse reaction in mammalian cells is catalyzed by acyl-protein thioesterases (APTs) in the cytosol and palmitoyl protein thioesterases in lysosomes.Because palmitoylation is a dynamic, post-translational process, it is believed to be employed by the cell to alter the subcellular localization, protein–protein interactions, or binding capacities of a protein.An example of a protein that undergoes palmitoylation is hemagglutinin, a membrane glycoprotein used by influenza to attach to host cell receptors.