Pinheiro Sandrine, Nadal-Ribelles Mariona, Solé Carme, Vincenzetti Vincent, Dusserre Yves, Posas Francesc, Pelet Serge
Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.
Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain.
PLoS Genet. 2025 Jun 16;21(6):e1011710. doi: 10.1371/journal.pgen.1011710. eCollection 2025 Jun.
Responses to extracellular signals via Mitogen-Activated Protein Kinase (MAPK) pathways control complex transcriptional programs where hundreds of genes are induced at a desired level with a specific timing. Gene expression regulation is largely encoded in the promoter of the gene, which harbors numerous transcription factor binding sites. In the mating MAPK pathway of Saccharomyces cerevisiae, one major transcription factor, Ste12, controls the chronology of gene expression necessary for the fusion of two haploid cells. Because endogenous promoters encode a large diversity of Ste12 binding sites (PRE), we engineered synthetic promoters to decipher the rules that dictate mating gene induction. Conformations of PRE dimers that allow efficient gene expression were identified. The strength of binding of Ste12 to the PRE and the distance of the binding sites to the core promoter modulate the level of induction. The speed of activation is ensured by favoring a basal association of Ste12 by using a strong dimer of PRE located in a nucleosome depleted region.
通过丝裂原活化蛋白激酶（MAPK）途径对细胞外信号的应答控制着复杂的转录程序，其中数百个基因在特定时间以所需水平被诱导表达。基因表达调控主要编码在基因的启动子中，启动子含有众多转录因子结合位点。在酿酒酵母的交配MAPK途径中，一个主要的转录因子Ste12控制着两个单倍体细胞融合所需的基因表达时间顺序。由于内源性启动子编码多种不同的Ste12结合位点（PRE），我们构建了合成启动子来解读决定交配基因诱导的规则。确定了允许有效基因表达的PRE二聚体构象。Ste12与PRE的结合强度以及结合位点与核心启动子的距离调节诱导水平。通过使用位于核小体缺失区域的强PRE二聚体来促进Ste12的基础结合，从而确保激活速度。
