Cell Fate and Gene Regulation Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
Nat Commun. 2020 May 8;11(1):2271. doi: 10.1038/s41467-020-16107-w.
Intrinsic signals and external cues from the environment drive cell fate decisions. In budding yeast, the decision to enter meiosis is controlled by nutrient and mating-type signals that regulate expression of the master transcription factor for meiotic entry, IME1. How nutrient signals control IME1 expression remains poorly understood. Here, we show that IME1 transcription is regulated by multiple sequence-specific transcription factors (TFs) that mediate association of Tup1-Cyc8 co-repressor to its promoter. We find that at least eight TFs bind the IME1 promoter when nutrients are ample. Remarkably, association of these TFs is highly regulated by different nutrient cues. Mutant cells lacking three TFs (Sok2/Phd1/Yap6) displayed reduced Tup1-Cyc8 association, increased IME1 expression, and earlier onset of meiosis. Our data demonstrate that the promoter of a master regulator is primed for rapid activation while repression by multiple TFs mediating Tup1-Cyc8 recruitment dictates the fate decision to enter meiosis.
内在信号和环境中的外部线索驱动细胞命运决定。在芽殖酵母中,进入减数分裂的决定受营养和交配型信号的控制,这些信号调节进入减数分裂的主转录因子 IME1 的表达。营养信号如何控制 IME1 的表达仍知之甚少。在这里,我们表明 IME1 转录受多个序列特异性转录因子 (TF) 的调节,这些转录因子介导 Tup1-Cyc8 共阻遏物与其启动子的结合。我们发现,当营养物质充足时,至少有八个 TF 结合在 IME1 启动子上。值得注意的是,这些 TF 的结合受到不同营养线索的高度调节。缺乏三个 TF(Sok2/Phd1/Yap6)的突变细胞显示出 Tup1-Cyc8 结合减少、IME1 表达增加和减数分裂更早开始。我们的数据表明,主调控因子的启动子已经为快速激活做好了准备,而多个介导 Tup1-Cyc8 募集的 TF 的抑制决定了进入减数分裂的命运决定。