10.1021/ja502109n.s003 Tao Peng Tao Peng Howard C. Hang Howard C. Hang Bifunctional Fatty Acid Chemical Reporter for Analyzing S‑Palmitoylated Membrane Protein–Protein Interactions in Mammalian Cells American Chemical Society 2015 membrane proteins IFITM 3 New strategies protein complexes acid chemical reporter IFITM 3 oligomerization Bifunctional Fatty Chemical Reporter Mammalian CellsStudying 2015-01-21 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Bifunctional_Fatty_Acid_Chemical_Reporter_for_Analyzing_S_Palmitoylated_Membrane_Protein_Protein_Interactions_in_Mammalian_Cells/2213836 Studying the functions of S-palmitoylated proteins in cells can be challenging due to the membrane targeting property and dynamic nature of protein S-palmitoylation. New strategies are therefore needed to specifically capture S-palmitoylated protein complexes in cellular membranes for dissecting their functions <i>in vivo</i>. Here we present a bifunctional fatty acid chemical reporter, x-alk-16, which contains an alkyne and a diazirine, for metabolic labeling of S-palmitoylated proteins and photo-cross-linking of their involved protein complexes in mammalian cells. We demonstrate that x-alk-16 can be metabolically incorporated into known S-palmitoylated proteins such as H-Ras and IFITM3, a potent antiviral protein, and induce covalent cross-linking of IFITM3 oligomerization as well as its specific interactions with other membrane proteins upon in-cell photoactivation. Moreover, integration of x-alk-16-induced photo-cross-linking with label-free quantitative proteomics allows identification of new IFITM3 interacting proteins.