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Pathway Description
Phosphatidylethanolamine Biosynthesis PE(18:3(9Z,12Z,15Z)/20:1(11Z))
Arabidopsis thaliana
Metabolic Pathway
Phosphatidylethanolamines (PE) are a class of phospholipids that incorporate a phosphoric acid headgroup into a diacylglycerol backbone. They are the second most abundant phospholipid in eukaryotic cell membranes, and contrary to phosphatidylcholine, it is concentrated with phosphatidylserine in the cell membrane's inner leaflet. In Arabidopsis thaliana, there exist two phosphatidylethanolamine biosynthesis pathways. The first pathway consists of mainly enzymes localized to either the cytosol or the cell membrane. Cell membrane-localized enzymes in this pathway are not drawn as such for clarity. Instead, they are indicated with a dark green colour and appear to be free floating in the cytosol. This first pathway begins with serine decarboxylase catalyzing the biosynthesis of ethanolamine from serine. It requires pyridoxal 5'-phosphate as a cofactor. Next, choline/ethanolamine kinase, localized to the cell membrane, catalyzes the conversion of ethanolamine to phosphoethanolamine. Then ethanolamine-phosphate cytidylyltransferase, localized to the mitochondria outer membrane, catalyzes the conversion of phosphoethanolamine to CDP-ethanolamine. Last, choline/ethanolaminephosphotransferase, localized to the cell membrane, catalyzes phosphatidylethanolamine CDP-ethanolamine, respectively. The second pathway consists of mainly enzymes localized to the endoplasmic reticulum membrane (also depicted in dark green in the image. Beginning in the cytosol, glycerol-3-phosphate dehydrogenase [NAD(+)] catalyzes the interconversion of glycerone phosphate (from glycolysis) and glycerol 3-phosphate. After glycerol 3-phosphate enters the endoplasmic reticulum, glycerol-3-phosphate acyltransferase esterifies the acyl-group from acyl-CoA to the sn-1 position of glycerol-3-phosphate. Third, 1-acyl-sn-glycerol-3-phosphate acyltransferase 2 catalyzes the conversion of lysophosphatidic acid (LPA or 1-acyl-sn-glycerol 3-phosphate) into phosphatidic acid (PA or 1,2-diacyl-sn-glycerol 3-phosphate) by incorporating an acyl moiety at the 2nd position. Fourth, phosphatidate cytidylyltransferase catalyzes the conversion of a 1,2-diacyl-sn-glycerol 3-phosphate into a CDP-diacylglycerol. It requires a magnesium ion as a cofactor. Fifth, CDP-diacylglycerol--serine O-phosphatidyltransferase catalyzes the synthesis of phosphatidylserine from L-serine and a CDP-diacylglycerol. Last, phosphatidylserine decarboxylase catalyzes the formation of phosphatidylethanolamine from phosphatidylserine. It requires pyruvate as a cofactor.
References
Phosphatidylethanolamine Biosynthesis PE(18:3(9Z,12Z,15Z)/20:1(11Z)) References
Yamaoka Y, Yu Y, Mizoi J, Fujiki Y, Saito K, Nishijima M, Lee Y, Nishida I: PHOSPHATIDYLSERINE SYNTHASE1 is required for microspore development in Arabidopsis thaliana. Plant J. 2011 Aug;67(4):648-61. doi: 10.1111/j.1365-313X.2011.04624.x. Epub 2011 Jun 24.
Pubmed: 21554450
Kim HU, Li Y, Huang AH: Ubiquitous and endoplasmic reticulum-located lysophosphatidyl acyltransferase, LPAT2, is essential for female but not male gametophyte development in Arabidopsis. Plant Cell. 2005 Apr;17(4):1073-89. doi: 10.1105/tpc.104.030403. Epub 2005 Mar 16.
Pubmed: 15772283
Alatorre-Cobos F, Cruz-Ramirez A, Hayden CA, Perez-Torres CA, Chauvin AL, Ibarra-Laclette E, Alva-Cortes E, Jorgensen RA, Herrera-Estrella L: Translational regulation of Arabidopsis XIPOTL1 is modulated by phosphocholine levels via the phylogenetically conserved upstream open reading frame 30. J Exp Bot. 2012 Sep;63(14):5203-21. doi: 10.1093/jxb/ers180. Epub 2012 Jul 12.
Pubmed: 22791820
Mendes A, Kelly AA, van Erp H, Shaw E, Powers SJ, Kurup S, Eastmond PJ: bZIP67 regulates the omega-3 fatty acid content of Arabidopsis seed oil by activating fatty acid desaturase3. Plant Cell. 2013 Aug;25(8):3104-16. doi: 10.1105/tpc.113.116343. Epub 2013 Aug 30.
Pubmed: 23995083
Tasseva G, Richard L, Zachowski A: Regulation of phosphatidylcholine biosynthesis under salt stress involves choline kinases in Arabidopsis thaliana. FEBS Lett. 2004 May 21;566(1-3):115-20. doi: 10.1016/j.febslet.2004.04.015.
Pubmed: 15147879
This pathway was generated using PathWhiz -
Pon, A. et al. Pathways with PathWhiz (2015) Nucleic Acids Res. 43(Web Server issue): W552–W559.
Generated from PW015072
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