Subcellular Analysis of Fatty Acid Metabolism Using Organelle-Selective Click Chemistry

The structural diversity of the fatty acids esterified in organellar membrane lipids is thought to confer the characteristic physiological properties of the membranes. However, the abundance profiles of fatty acid derivatives are still poorly characterized at organelle-level spatial resolution. Here, we have developed a technology for organelle-specific labeling and quantitative analysis of fatty acid derivatives involving the metabolic incorporation of azide fatty acids and organelle-localizing clickable dyes. This approach was used to investigate palmitate- and oleate-derived lipids in different organelle membranes. The relative abundances of fatty acid-containing lipids were found to differ depending on the organelle and the structure of the fatty acid. In addition, organelle-specific temporal variations in fatty acid derivatives were revealed that are difficult to detect using conventional lipid analysis.