Plasmenylethanolamine synthesis in Leishmania major

Abstract

SUMMARY Ethanolamine glycerophospholipids are ubiquitous cell membrane components. Trypanosomatid parasites of the genus Leishmania synthesize the majority of their ethanolamine glycerophospholipids as 1-O-alk-1′-enyl-2-acyl-sn-glycero-3-phosphoethanolamine or plasmenylethanolamine (PME) through the Kennedy pathway. PME is a subtype of ether phospholipids also known as ethanolamine plasmalogen whose functions are not well characterized. In this study, we investigated the role of PME synthesis in Leishmania major through the characterization of an ethanolamine phosphotransferase (EPT) mutant. EPT-null parasites are largely devoid of PME and fully viable in regular medium but fail to proliferate in the absence of fetal bovine serum. They exhibit significant abnormalities in the synthesis and localization of GPI-anchored surface molecules. EPT-null mutants also show attenuated virulence in BALB/c mice. Furthermore, in addition to PME synthesis, ethanolamine also contributes to the production of phosphatidylcholine, the most abundant class of lipids in Leishmania. Together, these findings suggest that ethanolamine production is likely required for Leishmania promastigotes to generate bulk phospholipids, to handle stress, and to control the expression of membrane bound virulence factors.

Phosphatidylcholine synthesis through cholinephosphate cytidylyltransferase is dispensable in Leishmania major

“…major . As we reported previously 23 , WT parasites were able to incorporate [ 3 H]-EtN into PE (PME + 1,2-diacyl-PE + lyso-PE or LPE 49 ) and PC (Fig. 4C and Fig.…”

“…A similar pathway is responsible for the de novo synthesis of phosphatidylethanolamine (PE), as ethanolamine (EtN) is phosphorylated by ethanolamine kinase (EK), and the resulting ethanolamine phosphate (EtN-P) is converted into CDP-EtN by ethanolaminephosphate cytidylyltransferase (EPCT). In Leishmania , CDP-EtN is utilized to synthesize either plasmenylethanolamine (PME) 23 or 1,2-diacyl-PE (Fig. 1).…”

“…1). It is known that Leishmania parasites can also synthesize PC through the N-methylation of PE using S-adenosine-methionine as the methyl donor 23,30 . This PE N-methylation pathway is the predominant PC synthesis route in hepatocytes 31 and Saccharomyces cerevisiae 32 , but is absent in Trypanosoma brucei 33,34 .…”

Cyclopropane fatty acid synthesis affects cell shape and acid resistance in Leishmania mexicana

“…In L. major , ablation of PME synthesis significantly altered the expression of LPG and GP63 (an abundant metalloprotease) which are important virulence factors for promastigotes (Pawlowic et al, 2016). To determine whether cyclopropanation of PME affects the expression of GPI-anchored molecules in L. mexicana , we examined the cellular levels of LPG and GP63 by western blot (Supplementary Fig.…”

Sterol methyltransferase is required for optimal mitochondrial function and virulence in Leishmania major

“…Sterol analysis was performed using GC-MS as previously described (Xu et al, 2014). To analyze phospholipids and sphingolipids, parasite lipids were extracted using the Bligh-Dyer approach (Bligh and Dyer, 1959) and examined by electron ionization mass spectrometry in the negative ion mode and positive ion mode as previously described (Pawlowic et al, 2016).…”