Publications

• Identification and characterization of the major lysophosphatidylethanolamine acyltransferase in Saccharomyces cerevisiae.

  Riekhof W.R., Wu J., Jones J.L., Voelker D.R.

  We recently demonstrated that yeast actively import lysophosphatidylethanolamine (lyso-PtdEtn) through the action of plasma membrane P-type ATPases and rapidly acylate it to form PtdEtn. The predominant lyso-PtdEtn acyltransferase (LPEAT) activity present in cellular extracts is acyl-CoA dependent ... >> More

  We recently demonstrated that yeast actively import lysophosphatidylethanolamine (lyso-PtdEtn) through the action of plasma membrane P-type ATPases and rapidly acylate it to form PtdEtn. The predominant lyso-PtdEtn acyltransferase (LPEAT) activity present in cellular extracts is acyl-CoA dependent, but the identity of the gene encoding this activity was unknown. We now demonstrate that a previously uncharacterized open reading frame, YOR175C, encodes the major acyl-CoA-dependent LPEAT activity in yeast and henceforth refer to it as ALE1 (acyltransferase for lyso-PtdEtn). Ale1p is an integral membrane protein and is highly enriched in the mitochondria-associated endoplasmic reticulum membrane. It is a member of the membrane-bound O-acyltransferase family and possesses a dibasic motif at its C terminus that is likely responsible for Golgi retrieval and retention in the endoplasmic reticulum. An ale1Delta strain retains only trace amounts of acyl-CoA-dependent LPEAT activity, and strains lacking the capacity for PtdEtn synthesis via the phosphatidylserine decarboxylase and Kennedy pathways show a stringent requirement for both exogenous lyso-PtdEtn and a functional ALE1 gene for viability. Ale1p catalytic activity has a pH optimum between pH 7 and 7.5 and a strong preference for unsaturated acyl-CoA substrates. << Less

  J. Biol. Chem. 282:28344-28352(2007) [PubMed] [EuropePMC]

  This publication is cited by 4 other entries.

• Discovery of a lysophospholipid acyltransferase family essential for membrane asymmetry and diversity.

  Hishikawa D., Shindou H., Kobayashi S., Nakanishi H., Taguchi R., Shimizu T.

  All organisms consist of cells that are enclosed by a cell membrane containing bipolar lipids and proteins. Glycerophospholipids are important not only as structural and functional components of cellular membrane but also as precursors of various lipid mediators. Polyunsaturated fatty acids compri ... >> More

  All organisms consist of cells that are enclosed by a cell membrane containing bipolar lipids and proteins. Glycerophospholipids are important not only as structural and functional components of cellular membrane but also as precursors of various lipid mediators. Polyunsaturated fatty acids comprising arachidonic acid or eicosapentaenoic acid are located at sn-2 position, but not at sn-1 position of glycerophospholipids in an asymmetrical manner. In addition to the asymmetry, the membrane diversity is important for membrane fluidity and curvature. To explain the asymmetrical distribution of fatty acids, the rapid turnover of sn-2 position was proposed in 1958 by Lands [Lands WE (1958) Metabolism of glycerolipides: A comparison of lecithin and triglyceride synthesis. J Biol Chem 231:883-888]. However, the molecular mechanisms and biological significance of the asymmetry remained unknown. Here, we describe a putative enzyme superfamily consisting mainly of three gene families, which catalyzes the transfer of acyl-CoAs to lysophospholipids to produce different classes of phospholipids. Among them, we characterized three important enzymes with different substrate specificities and tissue distributions; one, termed lysophosphatidylcholine acyltransferase-3 (a mammalian homologue of Drosophila nessy critical for embryogenesis), prefers arachidonoyl-CoA, and the other two enzymes incorporate oleoyl-CoAs to lysophosphatidylethanolamine and lysophosphatidylserine. Thus, we propose that the membrane diversity is produced by the concerted and overlapped reactions with multiple enzymes that recognize both the polar head group of glycerophospholipids and various acyl-CoAs. Our findings constitute a critical milestone for our understanding about how membrane diversity and asymmetry are established and their biological significance. << Less

  Proc. Natl. Acad. Sci. U.S.A. 105:2830-2835(2008) [PubMed] [EuropePMC]

  This publication is cited by 23 other entries.