Université de Fribourg

Influenza A virus induces autophagosomal targeting of ribosomal proteins

Becker, Andrea C. ; Gannagé, Monique ; Giese, Sebastian ; Hu, Zehan ; Abou-Eid, Shadi ; Roubaty, Carole ; Paul, Petra ; Bühler, Lea ; Gretzmeier, Christine ; Dumit, Veronica I. ; Kaeser-Pebernard, Stéphanie ; Schwemmle, Martin ; Münz, Christian ; Dengjel, Jörn

In: Molecular & Cellular Proteomics, 2018, vol. 17, no. 10, p. 1909–1921

Seasonal epidemics of influenza A virus are a major cause of severe illness and are of high socio-economic relevance. For the design of effective antiviral therapies, a detailed knowledge of pathways perturbed by virus infection is critical. We performed comprehensive expression and organellar proteomics experiments to study the cellular consequences of influenza A virus infection using three...

Université de Fribourg

Chemogenetic E-MAP in Saccharomyces cerevisiae for identification of membrane transporters operating lipid flip flop

Vazquez, Hector M. ; Vionnet, Christine ; Roubaty, Carole ; Mallela, Shamroop k. ; Schneiter, Roger ; Conzelmann, Andreas

In: PLOS Genet, 2016, vol. 12, no. 7, p. e1006160

While most yeast enzymes for the biosynthesis of glycerophospholipids, sphingolipids and ergosterol are known, genes for several postulated transporters allowing the flopping of biosynthetic intermediates and newly made lipids from the cytosolic to the lumenal side of the membrane are still not identified. An E-MAP measuring the growth of 142'108 double mutants generated by systematically...

Université de Fribourg

Topology of the microsomal glycerol-3-phosphate acyltransferase Gpt2p/Gat1p of Saccharomyces cerevisiae

Pagac, Martin ; Vazquez, Hector M. ; Bochud, Arlette ; Roubaty, Carole ; Knöpfli, Cécile ; Vionnet, Christine ; Conzelmann, Andreas

In: Molecular Biology, 2012, p. -

All glycerophospholipids are made from phosphatidic acid, which, according to the traditional view, is generated at the cytosolic surface of the ER. In yeast, phosphatidic acid is synthesized de novo by two acyl-CoA dependent acylation reactions. The first is catalyzed by one of the two homologous glycerol-3-phosphate acyltransferases Gpt2p/Gat1p and Sct1p/Gat2p, the second by one of the two...

Université de Fribourg

Yeast cells lacking all known ceramide synthases continue to make complex sphingolipids and to incorporate ceramides into glycosylphosphatidylinositol (GPI)

Vionnet, Christine ; Roubaty, Carole ; Ejsing, Christer S. ; Knudsen, Jens ; Conzelmann, Andreas

In: Journal of Biological Chemistry, 2011, vol. 286, p. 6769-6779

In yeast, the inositolphosphorylceramides mostly contain C26:0 fatty acids. Inositolphosphorylceramides were considered to be important for viability because the inositolphosphorylceramide synthase AUR1 is essential. However, lcb1Δ cells, unable to make sphingoid bases and inositolphosphorylceramides, are viable if they harbor SLC1-1, a gain of function mutation in the...

Université de Fribourg

Aureobasidin A arrests growth of yeast cells through both ceramide intoxication and deprivation of essential inositolphosphorylceramides

Cerantola, Vanessa ; Guillas, Isabelle ; Roubaty, Carole ; Vionnet, Christine ; Uldry, Danièle ; Knudsen, Jens ; Conzelmann, Andreas

In: Molecular Microbiology, 2009, vol. 71, no. 6, p. 1523 - 1537

All mature Saccharomyces cerevisiae sphingolipids comprise inositolphosphorylceramides containing C26:0 or C24:0 fatty acids and either phytosphingosine or dihydrosphingosine. Here we analysed the lipid profile of lag1Δlac1Δ mutants lacking acyl-CoA-dependent ceramide synthesis, which require the reverse ceramidase activity of overexpressed Ydc1p for sphingolipid biosynthesis and viability....

Université de Fribourg

Incorporation of ceramides into yeast glycosylphosphatidylinositol-anchored proteins can be monitored in vitro

Bosson, Régine ; Guillas, Isabelle ; Vionnet, Christine ; Roubaty, Carole ; Conzelmann, Andreas

In: Eukaryotic Cell, 2009, vol. 8, no. 3, p. 306-314

After glycosylphosphatidylinositols (GPIs) are added to GPI proteins of Saccharomyces cerevisiae, a fatty acid of the diacylglycerol moiety is exchanged for a C26:0 fatty acid through the subsequent actions of Per1 and Gup1. In most GPI anchors the thus modified diacylglycerol-based anchor is subsequently transformed into a ceramide-containing anchor, a reaction, which requires Cwh43. Here...

Université de Fribourg

SLC1 and SLC4 encode partially redundant acyl-Coenzyme A 1-acylglycerol-3-phosphate O-acyltransferases of budding yeast

Benghezal, Mohammed ; Roubaty, Carole ; Veepuri, Vijayanath ; Knudsen, Jens ; Conzelmann, Andreas

In: Journal of Biological Chemistry, 2007, p. jbc.M702719200

Phosphatidic acid (PA) is the intermediate, from which all glycerophospholipids are synthesized. In yeast it is generated from lyso-phosphatidic acid, which is acylated by Slc1p, a sn-2-specific, acyl-Coenzyme A-dependent 1-acylglycerol-3-phosphate O-acyltransferase. Deletion of SLC1 is not lethal and does not eliminate all microsomal 1-acylglycerol-3-phosphate O-acyltransferase activity...

Université de Fribourg

CWH43 is required for the introduction of ceramides into GPI anchors in Saccharomyces cerevisiae

Ghugtyal, Vikram ; Vionnet, Christine ; Roubaty, Carole ; Conzelmann, Andreas

In: Molecular Microbiology, 2007, vol. 65, no. 6, p. 1493-1502

After glycosylphosphatidylinositols (GPIs) are added to GPI proteins of Saccharomyces cerevisiae, the fatty acid in sn-2 of the diacylglycerol moiety can be replaced by a C26:0 fatty acid by a deacylation–reacylation cycle catalysed by Per1p and Gup1p. Furthermore the diacylglycerol moiety of the yeast GPI anchor can also be replaced by ceramides. CWH43 of yeast is...