N-Acylethanolamine is a Source of Ethanolamine for Phosphatidylethanolamine Synthesis in Trypanosoma brucei

The Kennedy pathway is essential for survival of Trypanosoma brucei procyclic and bloodstream form parasites in culture and provides the bulk of phosphatidylethanolamine and phosphatidylcholine for membrane biogenesis. The CDP-ethanolamine branch of the Kennedy pathway depends on a steady supply of ethanolamine to be functional. We now show that degradation of N-acylethanolamines, mediated at least in part by T. brucei fatty acid amide hydrolase (TbFAAH), represents an additional reaction to provide ethanolamine for phosphatidylethanolamine synthesis. Although TbFAAH is not essential for growth of T. brucei procyclic forms in normal culture medium, it may be essential for ethanolamine production under conditions of limited availability of free ethanolamine in the environment, or in the insect vector or mammalian host.