By Irene Hsiao
Over 800 proteins in human cells are modified by the addition or removal of palmitic acid, a saturated fatty acid produced by the body and found in many commonly consumed plant and animal products. To monitor the activity of the enzymes that govern its cellular regulation, Bryan Dickinson and his lab developed small molecule probes that fluoresce when palmitic acid has been “erased” from a protein. Using these probes, the Dickinson lab observed that skin cancer cells, which contain elevated numbers of epidermal growth factor (EGF) receptors, responded to EGF stimulation with a sharp decrease in depalmitoylation activity. These results, reported in Nature Chemical Biology, reveal that this lipid modification is dynamically regulated by its removal, indicating a new connection between lipids and cellular regulation with possible ramifications in metabolic diseases and cancer.