Biosynthesis of very long chain fatty acids in Trypanosoma cruzi

LIVORE, V; A. D. UTTARO

PARASITOLOGY RESEARCH

SPRINGER

Lugar: Berlin; Año: 2015 vol. 114 p. 265 - 271

0932-0113

Trypanosoma brucei and Trypanosoma cruzishowed similar fatty acid (FA) compositions, having a highproportion of unsaturated FAs, mainly 18:2Δ9,12 (23?39 %)and 18:1Δ9 (11?17 %). C22 polyunsaturated FAs are insignificant amounts only in T. brucei (12?20 %) but representa mere 2 % of total FAs in T. cruzi. Both species have alsosimilar profiles of medium- and long-chain saturated FAs,from 14:0 to 20:0. Interestingly, procyclic and bloodstreamforms of T. brucei lack very long chain FAs (VLCFAs),whereas epimastigotes and trypomastigotes of T. cruzi contain22:0 (0.1?0.2 %), 24:0 (1.5?2 %), and 26:0 (0.1?0.2 %). Thisis in agreement with the presence of an additional FA elongasegene (TcELO4) in T. cruzi. TcELO4 was expressed in aSaccharomyces cerevisiae mutant lacking the endogenousScELO3, rescuing the synthesis of saturated and hydroxylatedC26 FAs in the yeast. Expression of TcELO4 also rescued thesynthetic lethality of a ScELO2, ScELO3 double mutation,and the VLCFA profile of the transformed yeast was similar tothat found in T. cruzi. By identifying TcELO4 as theenzyme responsible for the elongation of FA from16:0 and 18:0 up to 26:0, with 24:0 being the preferredproduct, this work completed the characterization of FAelongases in Trypanosoma spp.