Localization of the initial steps in alkoxyphospholipid biosynthesis in glycosomes (microbodies) of Trypanosoma brucei.

Cell fractionation of Trypanosoma brucei cultured procyclic stages showed that the key enzyme of glycerol-ether lipid synthesis, dihydroxyacetone-phosphate acyltransferase (EC 2.3.1.42) was exclusively associated with the microbody fraction. These organelles contained in addition 1-acyl glycerol-3-phosphate: NADP+ oxidoreductase (EC 1.1.1.101) and acyl-CoA reductase and were capable of utilizing DHAP, but not G-3-P, as substrate for lysophosphatidic acid formation. It is concluded that in T. brucei the glycosomes are the exclusive site of the synthesis of precursors for glycerol-ether lipid synthesis and that they contain the entire pathway to form alkoxylipids from glycerol and acyl-CoA.