1
|
Dittrich-Domergue F, Joubès J, Moreau P, Lessire R, Stymne S, Domergue F. The bifunctional protein TtFARAT from Tetrahymena thermophila catalyzes the formation of both precursors required to initiate ether lipid biosynthesis. J Biol Chem 2014; 289:21984-94. [PMID: 24917677 PMCID: PMC4139215 DOI: 10.1074/jbc.m114.579318] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 06/03/2014] [Indexed: 11/06/2022] Open
Abstract
The biosynthesis of ether lipids and wax esters requires as precursors fatty alcohols, which are synthesized by fatty acyl reductases (FARs). The presence of ether glycerolipids as well as branched wax esters has been reported in several free-living ciliate protozoa. In the genome of Tetrahymena thermophila, the only ORF sharing similarities with FARs is fused to an acyltransferase-like domain, whereas, in most other organisms, FARs are monofunctional proteins of similar size and domain structure. Here, we used heterologous expression in plant and yeast to functionally characterize the activities catalyzed by this protozoan protein. Transient expression in tobacco epidermis of a truncated form fused to the green fluorescence protein followed by confocal microscopy analysis suggested peroxisomal localization. In vivo approaches conducted in yeast indicated that the N-terminal FAR-like domain produced both 16:0 and 18:0 fatty alcohols, whereas the C-terminal acyltransferase-like domain was able to rescue the lethal phenotype of the yeast double mutant gat1Δ gat2Δ. Using in vitro approaches, we further demonstrated that this domain is a dihydroxyacetone phosphate acyltransferase that uses preferentially 16:0-coenzyme A as an acyl donor. Finally, coexpression in yeast with the alkyl-dihydroxyacetone phosphate synthase from T. thermophila resulted the detection of various glycerolipids with an ether bond, indicating reconstitution of the ether lipid biosynthetic pathway. Together, these results demonstrate that this FAR-like protein is peroxisomal and bifunctional, providing both substrates required by alkyl-dihydroxyacetone phosphate synthase to initiate ether lipid biosynthesis.
Collapse
Affiliation(s)
- Franziska Dittrich-Domergue
- From the Université de Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, the Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, and
| | - Jérôme Joubès
- From the Université de Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, the Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, and
| | - Patrick Moreau
- From the Université de Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, the Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, and
| | - René Lessire
- From the Université de Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, the Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, and
| | - Sten Stymne
- the Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O.B. 101, 23053 Alnarp, Sweden
| | - Frédéric Domergue
- From the Université de Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, the Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, UMR 5200, 33000 Bordeaux, France, and
| |
Collapse
|
2
|
Biester EM, Hellenbrand J, Frentzen M. Multifunctional acyltransferases from Tetrahymena thermophila. Lipids 2012; 47:371-81. [PMID: 22160552 PMCID: PMC3311841 DOI: 10.1007/s11745-011-3642-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 11/23/2011] [Indexed: 10/27/2022]
Abstract
Multifunctional acyltransferases are able to catalyze the esterification of various acyl-acceptors with activated fatty acids. Here we describe the identification of four proteins from Tetrahymena thermophila that share certain properties with mammalian acyltransferases regarding their predicted transmembrane structure, their molecular mass and the typical acyltransferase motif. Expression of the Tetrahymena sequences results in production of triacylglycerols and wax esters in recombinant yeast when appropriate substrates are provided. The in vitro characterization shows, that these enzymes are capable of esterifying different acyl-acceptors including fatty alcohols, diols, diacylglycerols and isoprenols with acyl-CoA thioesters. Based on these catalytic activities and the sequence similarities of the Tetrahymena proteins with acyl-CoA:diacylglycerol acyltransferase 2 (DGAT2) family members, we conclude that we identified a new group of DGAT2-related multifunctional acyltransferases from protozoan organisms.
Collapse
Affiliation(s)
- Eva-Maria Biester
- Institute for Biology I, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany.
| | | | | |
Collapse
|