Selective Editing and Functionalization of the Mammalian Lipidome

Abstract Lipids exhibit extraordinary molecular diversity, yet tools to selectively manipulate defined lipid classes in living cells are lacking. Here we show that lipid tail structure biases metabolic fate, enabling the design of synthetic lipid analogs with programmable metabolic selectivity. This approach enables selective cellular production of distinct lipid species or subclasses, including types of neutral lipids, phospholipids, sphingolipids, and ether lipids, without genetic or enzymatic perturbation. We further couple metabolic selectivity to chemical functionalization using bifunctional lipids, in which one modification directs metabolic flux and a second enables bioorthogonal tagging. Using this strategy, we achieve selective in situ labeling of different lipid pools in living cells. Together, our work establishes a chemical biology strategy that enables unprecedented precision in modulating, functionalizing, and rewiring the mammalian lipidome.