The Trypanosoma brucei dihydroxyacetonephosphate acyltransferase TbDAT is dispensable for normal growth but important for synthesis of ether glycerophospholipids

Abstract

Glycerophospholipids are the most abundant constituents of biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans and nagana in cattle. They are essential cellular components that fulfill various important functions beyond their structural role in biological membranes such as in signal transduction, regulation of membrane trafficking or control of cell cycle progression. Our previous studies have established that the glycerol-3-phosphate acyltransferase TbGAT is dispensable for growth, viability, and ester lipid biosynthesis suggesting the existence of another initial acyltransferase(s). This work presents the characterization of the alternative, dihydroxyacetonephosphate acyltransferase TbDAT, which acylates primarily dihydroxyacetonephosphate and prefers palmitoyl-CoA as an acyl-CoA donor. TbDAT restores the viability of a yeast double null mutant that lacks glycerol-3-phosphate and dihydroxyacetonephosphate acyltransferase activities. A conditional null mutant of TbDAT in T. brucei procyclic form was created and characterized. TbDAT was important for survival during stationary phase and synthesis of ether lipids. In contrast, TbDAT was dispensable for normal growth. Our results show that in T. brucei procyclic forms i) TbDAT but not TbGAT is the physiologically relevant initial acyltransferase and ii) ether lipid precursors are primarily made by TbDAT.

Alterations of Gut Microbiome and Metabolite Profiling in Mice Infected by Schistosoma japonicum

“…As the major structural lipids that form cellular membranes, phospholipids participate in the regulation of nutrient transport as well as toxic host-cell effector molecules; they are synthesized to support the growth of cells in the course of infection, and phospholipid biosynthetic pathways are the targets of drugs ( 66 – 68 ). Our results demonstrated that most of the altered lipids belonged to glycerophospholipids, which are structural components of biological membranes ( 69 ), followed by sphingolipids and diacylglycerol. The majority of glycerophospholipids were significantly reduced in response to the infection, such as PC, phosphatidylethanolamine (PE), phosphatidylserine, phosphatidylinositol, and LysoPC.…”

Phospholipids containing ether-bound hydrocarbon-chains are essential for efficient phagocytosis and neutral lipids of the ester-type perturb development in Dictyostelium

“…DHAPAT enzymes from Leishmania ( Al-Ani et al, 2011 ) and Trypanosoma ( Zufferey et al, 2017 ) are much larger than their mammalian counterparts because they contain an N-terminal extension of unknown function. Interestingly, the ciliate Tetrahymena encodes the same bifunctional FARAT protein ( Dittrich-Domergue et al, 2014 ) as Dictyostelium , where the N-terminal extension encodes a functional fatty acid reductase domain ( Dittrich-Domergue et al, 2014 ) that may provide the fatty alcohol for the subsequent step in ether lipid synthesis ( Fig.…”

“…7 ), catalysed by ADPS ( Razeto et al, 2007 ). Whereas functional experiments on the Tetrahymena enzyme had to be performed in yeast ( Dittrich-Domergue et al, 2014 ), the loss of DHAPAT in Trypanosomes appears to be lethal, but in a conditional mutant all ether lipid species decline, with a concomitant increase on ester phospholipids ( Zufferey et al, 2017 ). The Dictyostelium fatA – mutant is almost devoid of the neutral lipid MDG, and residual amounts are assumed to originate from one of the surprisingly many polyketide synthases encoded in the genome ( Zucko et al, 2007 ).…”

Lipidomics and anti‐trypanosomatid chemotherapy

“…These analyses established that Lmj PEM1 added the first and second methyl group to PE, while Lmj PEM2 catalyzed all three methylation steps, although the addition of the first methyl group occurred very inefficiently. T. brucei possesses two initial acyltransferases, the glycerol‐3‐phosphate acyltransferase Tb GAT, which is dispensable for glycerolipid biosynthesis and growth of procyclic forms, and the dihydroxyacetonephosphate acyltransferase Tb DAT, which is essential for ether lipid production [62,63]. The role of T. brucei Tb PLA 1 in PC metabolism was investigated by global lipidomics investigation [64].…”