Department of Food Science, Cornell University, Ithaca, NY 14853, USA.
Biology Program, California State University-Channel Islands, Camarillo, CA 93012, USA.
G3 (Bethesda). 2022 Nov 4;12(11). doi: 10.1093/g3journal/jkac196.
In the yeast Saccharomyces cerevisiae, trehalose-6-phospahte synthase (Tps1) and trehalose-6-phosphate phosphatase (Tps2) are the main proteins catalyzing intracellular trehalose production. In addition to Tps1 and Tps2, 2 putative regulatory proteins with less clearly defined roles also appear to be involved with trehalose production, Tps3 and Tsl1. While this pathway has been extensively studied in laboratory strains of S. cerevisiae, we sought to examine the phenotypic consequences of disrupting these genes in wild strains. Here we deleted the TPS1, TPS2, TPS3, and TSL1 genes in 4 wild strains and 1 laboratory strain for comparison. Although some tested phenotypes were not shared between all strains, deletion of TPS1 abolished intracellular trehalose, caused inability to grow on fermentable carbon sources and resulted in severe sporulation deficiency for all 5 strains. After examining tps1 mutant strains expressing catalytically inactive variants of Tps1, our results indicate that Tps1, independent of trehalose production, is a key component for yeast survival in response to heat stress, for regulating sporulation, and growth on fermentable sugars. All tps2Δ mutants exhibited growth impairment on nonfermentable carbon sources, whereas variations were observed in trehalose synthesis, thermosensitivity and sporulation efficiency. tps3Δ and tsl1Δ mutants exhibited mild or no phenotypic disparity from their isogenic wild type although double mutants tps3Δ tsl1Δ decreased the amount of intracellular trehalose production in all 5 strains by 17-45%. Altogether, we evaluated, confirmed, and expanded the phenotypic characteristics associated trehalose biosynthesis mutants. We also identified natural phenotypic variants in multiple strains that could be used to genetically dissect the basis of these traits and then develop mechanistic models connecting trehalose metabolism to diverse cellular processes.
在酵母酿酒酵母中，海藻糖-6-磷酸合酶（Tps1）和海藻糖-6-磷酸磷酸酶（Tps2）是催化细胞内海藻糖生成的主要蛋白。除了 Tps1 和 Tps2，还有 2 种功能不太明确的假定调节蛋白 Tps3 和 Tsl1，似乎也与海藻糖生成有关。虽然该途径在实验室酵母菌株中得到了广泛研究，但我们试图研究在野生菌株中破坏这些基因的表型后果。在这里，我们在 4 种野生株和 1 种实验室株中敲除了 TPS1、TPS2、TPS3 和 TSL1 基因进行比较。尽管一些测试表型并非所有菌株都具有，但 TPS1 的缺失使细胞内海藻糖消失，无法在可发酵碳源上生长，并导致所有 5 株菌的严重孢子形成缺陷。在研究表达 Tps1 催化失活变体的 tps1 突变株后，我们的结果表明，Tps1 独立于海藻糖生成，是酵母应对热应激、调节孢子形成和可发酵糖生长的关键组成部分。所有 tps2Δ 突变株在非可发酵碳源上的生长受损，而在海藻糖合成、热敏性和孢子形成效率方面存在差异。tps3Δ 和 tsl1Δ 突变株与它们的同型野生型相比表现出轻微或没有表型差异，尽管双突变株 tps3Δ tsl1Δ 使所有 5 株菌的细胞内海藻糖生成量减少了 17-45%。总之，我们评估、证实和扩展了与海藻糖生物合成突变体相关的表型特征。我们还在多个菌株中鉴定了自然表型变体，这些变体可用于遗传剖析这些性状的基础，然后建立将海藻糖代谢与多种细胞过程联系起来的机制模型。
