Diacylglyceryl-N,N,N-trimethylhomoserine-dependent lipid remodeling in a green alga, Chlorella kessleri

Abstract

Membrane lipid remodeling contributes to the environmental acclimation of plants. In the green lineage, a betaine lipid, diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), is included exclusively among green algae and nonflowering plants. Here, we show that the green alga Chlorella kessleri synthesizes DGTS under phosphorus-deficient conditions through the eukaryotic pathway via the ER. Simultaneously, phosphatidylcholine and phosphatidylethanolamine, which are similar to DGTS in their zwitterionic properties, are almost completely degraded to release 18.1% cellular phosphorus, and to provide diacylglycerol moieties for a part of DGTS synthesis. This lipid remodeling system that substitutes DGTS for extrachloroplast phospholipids to lower the P-quota operates through the expression induction of the BTA1 gene. Investigation of this lipid remodeling system is necessary in a wide range of lower green plants for a comprehensive understanding of their phosphorus deficiency acclimation strategies.

Food authentication: truffle species classification by non-targeted lipidomics analyses using mass spectrometry assisted by ion mobility separation

“…They also frequently occur as direct substituents of phospholipids. 41 In the present study, the identified DGTSs and LDGTSs could only be detected in higher concentrations in the T. borchii samples, while the identified phospholipids were present in the samples of T. magnatum in most cases at higher signal intensities. Therefore, it can be assumed that these differences in the two white truffle species are also due to the fact that PCs and PEs can be replaced by DGTS and LDGTS, respectively.…”

Lipidomics Analysis of Multilamellar Bodies Produced by Amoeba Acanthamoeba castellanii in Co-Culture with Klebsiella aerogenes

“…According to some reports, when the content of DGTS in membranes increases, zwitterionic PLs such as PE and PC are almost completely simultaneously degraded. Thus, it can be concluded that phospholipids, mostly PC, provide diacylglycerol moieties for a part of DGTS synthesis [ 23 , 24 ]. Because eicosatetraenoic acid (C20:4 Δ 5,8,11,14 ) is known to be mostly incorporated into PC and PE in Acanthamoeba [ 25 ], and in the course of the current study we established that few molecular species of DGTS are substituted with C20:4, it seems that such a remodeling system might also occur in MLBs.…”

Do betaine lipids replace phosphatidylcholine as fatty acid editing hubs in microalgae?

“…Under optimal growth conditions, the green alga Chlorella kessleri does not contain DGTS, and contains PC as the dominant extraplastidic lipid. Within 48 hours of transfer to phosphorus-deficient conditions, this alga almost completely replaces the phospholipids PC and phosphatidylethanolamine (PE) with an equivalent amount of DGTS ( Oishi et al., 2022 ). Interestingly, the fatty acid composition of DGTS was nearly identical to that of PC and PE in phosphorus-replete conditions ( Oishi et al., 2022 ).…”

“…Within 48 hours of transfer to phosphorus-deficient conditions, this alga almost completely replaces the phospholipids PC and phosphatidylethanolamine (PE) with an equivalent amount of DGTS ( Oishi et al., 2022 ). Interestingly, the fatty acid composition of DGTS was nearly identical to that of PC and PE in phosphorus-replete conditions ( Oishi et al., 2022 ). C. kessleri was found to contain a homolog of the C. reinhardtii BTA1 gene, and the expression of this gene appears to be induced under phosphorus-deprived conditions in order to lower the alga’s phosphorus demand ( Oishi et al., 2022 ).…”

“…Interestingly, the fatty acid composition of DGTS was nearly identical to that of PC and PE in phosphorus-replete conditions ( Oishi et al., 2022 ). C. kessleri was found to contain a homolog of the C. reinhardtii BTA1 gene, and the expression of this gene appears to be induced under phosphorus-deprived conditions in order to lower the alga’s phosphorus demand ( Oishi et al., 2022 ). Similar findings were reported in the heterokont Nannochloropsis oceanica , which contains both DGTS and PC under nutrient replete growth conditions.…”