Lazar Zbigniew, Neuvéglise Cécile, Rossignol Tristan, Devillers Hugo, Morin Nicolas, Robak Małgorzata, Nicaud Jean-Marc, Crutz-Le Coq Anne-Marie
Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; Department of Biotechnology and Food Microbiology, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
Fungal Genet Biol. 2017 Mar;100:1-12. doi: 10.1016/j.fgb.2017.01.001. Epub 2017 Jan 5.
Sugar assimilation has been intensively studied in the model yeast S. cerevisiae, and for two decades, it has been clear that the homologous HXT genes, which encode a set of hexose transporters, play a central role in this process. However, in the yeast Yarrowia lipolytica, which is well-known for its biotechnological applications, sugar assimilation is only poorly understood, even though this yeast exhibits peculiar intra-strain differences in fructose uptake: some strains (e.g., W29) are known to be slow-growing in fructose while others (e.g., H222) grow rapidly under the same conditions. Here, we retrieved 24 proteins of the Sugar Porter family from these two strains, and determined that at least six of these proteins can function as hexose transporters in the heterologous host Saccharomyces cerevisiae EBY.VW4000. Transcriptional studies and deletion analysis in Y. lipolytica indicated that two genes, YHT1 and YHT4, are probably the main players in both strains, with a similar role in the uptake of glucose, fructose, and mannose at various concentrations. The other four genes appear to constitute a set of 'reservoir' hexose transporters with an as-yet unclear physiological role. Furthermore, through examining Sugar Porters of the entire Yarrowia clade, we show that they constitute a dynamic family, within which hexose transport genes have been duplicated and lost several times. Our phylogenetic analyses support the existence of at least three distinct evolutionary groups of transporters which allow yeasts to grow on hexoses. In addition to the well-known and widespread Hxt-type transporters (which are not essential in Y. lipolytica), we highlight a second group of transporters, represented by Yht1, which are phylogenetically related to sensors that play a regulatory role in S. cerevisiae, and a third group, represented by Yht4, previously thought to contain only high-affinity glucose transporters related to Hgt1of Kluyveromyces lactis.
在模式酵母酿酒酵母中，糖同化作用已得到深入研究。二十年来，很明显，编码一组己糖转运蛋白的同源HXT基因在这一过程中起着核心作用。然而，在以生物技术应用而闻名的解脂耶氏酵母中，尽管该酵母在果糖摄取方面表现出菌株内的特殊差异：一些菌株（如W29）已知在果糖中生长缓慢，而其他菌株（如H222）在相同条件下生长迅速，但对糖同化作用的了解却很少。在这里，我们从这两个菌株中检索到24种糖转运蛋白家族的蛋白质，并确定其中至少有6种蛋白质可以在异源宿主酿酒酵母EBY.VW4000中作为己糖转运蛋白发挥作用。在解脂耶氏酵母中的转录研究和缺失分析表明，两个基因YHT1和YHT4可能是这两个菌株中的主要参与者，在摄取不同浓度的葡萄糖、果糖和甘露糖方面具有相似作用。其他四个基因似乎构成了一组生理作用尚不清楚的“储备”己糖转运蛋白。此外，通过研究整个解脂耶氏酵母进化枝的糖转运蛋白，我们表明它们构成了一个动态家族，其中己糖转运基因已经多次复制和丢失。我们的系统发育分析支持至少存在三个不同的转运蛋白进化组，这些转运蛋白使酵母能够在己糖上生长。除了众所周知且广泛存在的Hxt型转运蛋白（在解脂耶氏酵母中不是必需的）外，我们还强调了第二组转运蛋白，以Yht1为代表，它们在系统发育上与在酿酒酵母中起调节作用的传感器相关；以及第三组转运蛋白，以Yht4为代表，以前认为只包含与乳酸克鲁维酵母的Hgt1相关的高亲和力葡萄糖转运蛋白。
