Chen Hong, Blum Jamie E, Thalacker-Mercer Anna, Gu Zhenglong
Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States.
Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States.
Front Mol Biosci. 2021 Mar 16;8:656461. doi: 10.3389/fmolb.2021.656461. eCollection 2021.
Evolution of aerobic fermentation (crabtree effect) in yeast is associated with the whole genome duplication (WGD) event, suggesting that duplication of certain genes may have altered yeast metabolism. The pyruvate kinase (PYK) gene is associated with alterations in cell metabolism, and duplicated during the WGD, generating PYK1 and PYK2. Thus, the impact of WGD on PYK activity and role of PYK in yeast metabolism were explored. PYK activity in the presence or absence of fructose-1,6-bisphosphate (FBP) was compared between pre- and post-WGD yeast. Glucose consumption, ethanol production, and oxygen consumption were measured in wildtype yeast and yeast with a T403E point mutation, which alters FBP binding affinity. FBP stimulated increased PYK activity in pre-WGD yeast and in the PYK1 isoforms of post-WGD yeast, but not in the PYK2 isoforms of post-WGD yeast. Compared to wildtype, T403E mutant yeast displayed reduced glucose consumption, reduced ethanol production, and increased mitochondrial metabolism. The WGD event impacted the sensitivity of PYK activity to FBP. Mutations in the FBP binding domain of PYK induce metabolic shifts that favor respiration and suppress fermentation.
酵母中需氧发酵（克奈特效应）的进化与全基因组复制（WGD）事件相关，这表明某些基因的复制可能改变了酵母的新陈代谢。丙酮酸激酶（PYK）基因与细胞代谢的改变有关，并且在WGD期间发生了复制，产生了PYK1和PYK2。因此，研究了WGD对PYK活性的影响以及PYK在酵母代谢中的作用。比较了WGD前后酵母在有无1,6-二磷酸果糖（FBP）情况下的PYK活性。在野生型酵母和具有T403E点突变（该突变改变了FBP结合亲和力）的酵母中测量了葡萄糖消耗、乙醇产生和氧气消耗。FBP刺激WGD前酵母以及WGD后酵母的PYK1亚型中PYK活性增加，但不刺激WGD后酵母的PYK2亚型。与野生型相比，T403E突变酵母的葡萄糖消耗减少、乙醇产生减少且线粒体代谢增加。WGD事件影响了PYK活性对FBP的敏感性。PYK的FBP结合域中的突变诱导了有利于呼吸作用并抑制发酵的代谢转变。
