Phosphatidylethanolamine (PE) is a ubiquitous lipid species in higher eukaryotes. Here, we synthesized a multifunctionalized PE derivative (1) designed to identify PE-binding proteins in intact cells through photo-crosslinking and subsequent isolation and proteomic analysis of the PE-protein conjugates. We show that the tool is also useful for tracking PE translocation to mitochondria after uncaging. A trifunctional phosphatidic acid derivative was rapidly metabolized and is of more limited …