Fatty acid acylation of proteins in cultured cells

Addition of [3H]palmitic acid to chick embryo fibroblasts labeled a set of membrane proteins that was distinct from those proteins labeled with [3H]leucine or [3H]mannose when examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The palmitate label, but not the mannose or leucine label, was removed from the proteins by treating electropherograms with hydroxylamine prior to fluorographic analysis. This result and other data indicate that the fatty acid labeling of cell proteins was analogous to that recently described for fatty acid acylation of three virus membrane glycoproteins. Mouse and human cultured cell lines show a similar set of protein-bound fatty acid, and we propose that fatty acid acylation is a general cellular activity that modifies proteins destined to become membrane-bound.