Conference Report: 12th Yeast Lipid Conference in Ghent, Belgium, 20-22 May 2015

Lipids on Medieval Waters
Inge Bogaert, Ghent University, Inge.VanBogaert@UGent.be
At the end of May 2015 yeast lipid experts from around the world gathered for their biannual meeting. After the previous oversees meeting in Halifax (Canada) in 2013, the 12th Yeast Lipid Conference was hosted again in Europe. Central Belgium was the place to be and the conference participants were welcomed to the lively and pleasant city of Ghent in the Faculty of Bioscience Engineering at Ghent University.
The conference started on Wednesday evening May 20th, and after some welcoming words from the local organizer Inge Van Bogaert and from the founder of the Yeast Lipid Conferences, Günther Daum, the activities of FEMS, the meeting’s main sponsor, were highlighted. Thanks to their financial support, the organizers were able to allocate conference grants to six young scientists. The remainder of the evening was devoted to the key-note lecture by William Prinz (Bethesda, USA) on mechanisms and functions of lipid exchange at membrane contact sites. He discussed lipid exchange at two contacts: endoplasmic reticulum (ER) to mitochondria, and the ER to Golgi complex. Besides the previously identified ER-mitochondrial tether called ERMES, his talk identified interactions between the ER membrane complex (Emc) and the TOM complex in the outer membrane of mitochondria, which facilitates phosphatidylserine transfer to mitochondria. He also described a new complex between Tom70/71 on mitochondria and the ER protein Ltc1/Lam6, which is implicated in sterol traffic. On the other hand, he found that Nvj2p facilitates ceramide transfer from the ER to the Golgi complex, helping to alleviate the toxic accumulation of ceramide in the ER that can occur during ER stress.
The topic of lipid transfer, dynamics and tethering was touched upon on several occasions during the second day of the meeting. The different components of the ERMES complex for instance and their interaction with Pex11 on peroxisomes were discussed in detail by Uroš Petrovi? (Ljubljana, Slovenia). Xue Bao (Utrecht, The Netherlands) gave a short talk on the importance of transport to mitochondrial sinks of unsaturated lipids when they are in excess. Roger Schneiter (Fribourg, Switzerland) examined several hypotheses for how lipid droplets form in relation to the ER, and he suggested that lipid droplets form within the ER lumen. Symeon Siniossoglou (Cambridge, UK) described his work on the lipin PA phosphatase homolog Pah1 in a novel domain that forms between nuclear envelope and lipid droplets following the diauxic shift. Jan Malinsky (Prague, Czech Republic) presented work on the role of sphingolipids in forming plasma membrane lipid microdomains.
Several aspects of phospholipids were discussed as well. George Carman (Rutgers, USA) focused on the regulation of Pah1, controlling the destination of lipids between triacylglycerols (storage) and phospholipids (new membrane). Karin Athenstaedt from Graz, Austria also had a look at the regulatory level, this time of the glycerol-3-phosphate acyltransferases Gat1p and Gat2p. The importance of degradation of phosphatidylglycerol for mitochondrial morphology and function was discussed by Maria Balážová (Ivanka pri Dunaji, Slovakia). Toon De Kroon showed how yeast can survive in the complete absence of phosphatidylcholine, and how this affects the yeast lipidome: there mainly is an effect on phosphatidylethanolamine (PE) with increasing acyl chain saturation and acyl chain shortening.
The Chair of the Yeast Lipid Conference Steering Committee, Günther Daum (Graz, Austria) gave an overview of the triacylglycerol lipase regulatory network. Vice-chair Tim Levine (London, UK) demonstrated the potential of profile-profile based predictions for the elucidation of protein function by a case study on the pleckstrin homology domains.
All of the above talks related to Saccharomyces cerevisiae, but Rémi Dulerma (Jouy-en-Josas, France) unraveled the fatty acid transport and activation in Yarrowia lipolytica and made the comparison with S. cerevisiae. The next day, his colleague Jean-Marc Nicaud presented this yeast as a platform for lipid production and discussed several strategies to obtain higher yields and accumulate special fatty acids. All other talks of this last conference day continued with this strong applied theme. Richard Gross (Rensselaer, USA) elaborated on the production of omega-hydroxy fatty acids by engineered Candida tropicalis strains, and several speakers investigated the potential of lipid production on hemicellulosic materials: Telma Franco from Brazil (Campinas) presented the strengths of Lipomyces starkeyi, while Lina Lindahl (Gothenburg, Sweden) investigated the link between the high acetic acid tolerance of Zygosaccharomyces bailli and its membrane composition. Yeast that are even more unconventional were also discussed: Katarzyna Ciesielska (Ghent, Belgium) shared her discovery of an extraordinary lactone esterase in the exoproteome of Starmerella bombicola; and Teresa Lopes da Silva (Lisbon, Portugal) explained how Rhodosporidium toruloides can act as a source of biodiesel and carotenoids. Of course, S. cerevisiae can also be used for the synthesis of chemicals and biofuels: Verena Siewers (Gothenburg, Sweden) presented several strain engineering strategies for this purpose, and Zita Purkrtova (Versailles, France) investigated if plant genes can contribute to increased lipid accumulation.
Steven Kelly (Swansea, UK) opened the afternoon session on yeast lipids and human health by sharing his new insights on sterol synthesis inhibitors targeting CYP51 in pathogenic fungi. Another aspect of this enzyme and its role in azole tolerance was highlighted by Alessandro Fiori (Leuven, Belgium): dual localization to both ER and mitochondria. Caroline Pohl (Bloemfontein, South Africa) discussed the role of eicosanoids in pathogenic Candida species. Kalervo Hiltunen (Oulu, Finland) explained how yeast models can be used to study human mitochondrial fatty acid synthesis. And finally Vladimir Titorenko (Quebec, Canada) described how induced yeast liponecrosis can allow yeast to model cell responses to anti-tumor therapeutic agents.
All work and no play makes Jack a dull boy, so in order to get acquainted with each other and the host city, we kicked off with an opening pasta buffet at the conference venue and on the second evening the majority of the conferees took off for an amusing guided boat tour on the medieval waters of Ghent, followed by a dinner in a historic setting. Some of the participants noticed the blue-white colors in the city centre, and indeed, the city soccer team was playing a crucial match at that very moment, becoming Belgium champions later that evening to great cheer in the streets, cafés and bars. Those who stayed over till Saturday evening enjoyed the celebration festivities even more.
The venue and date for the next, 13th Yeast Lipid Conferences was announced. It will take place in Paris (France) on 17-19 May 2017, and will be hosted by Jean-Marc Nicaud (INRA, France). Information about future and previous YLCs can be found on their website.