In response to nutrient starvation, the budding yeast Saccharomyces cerevisiae abandons mitotic proliferation and embarks on a differentiation process that leads through meiosis to the formation of haploid spores. This process is driven by cascading waves of meiosis-specific-gene expression. The early meiosis-specific genes are repressed during mitotic proliferation by the DNA-binding protein Ume6 in combination with repressors Rpd3 and Sin3. The expression of meiosis-specific transcription factor Ime1 leads to activation of the early meiosis-specific genes. We investigated the stability and promoter occupancy of Ume6 in sporulating cells and determined that it remains bound to early meiosis-specific gene promoters when those genes are activated. Furthermore, we find that the repressor Rpd3 remains associated with Ume6 after the transactivator Ime1 has joined the complex and that the Gcn5 and Tra1 components of the SAGA complex bind to the promoter of IME2 in an Ime1-dependent fashion to induce transcription of the early meiosis-specific genes. Our investigation supports a model whereby Ume6 provides a platform allowing recruitment of both activating and repressing factors to coordinate the expression of the early meiosis-specific genes in Saccharomyces cerevisiae.

中文翻译：

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Ume6 作为一个稳定的平台来协调酿酒酵母中早期减数分裂特异性基因的抑制和激活。

为了应对营养饥饿，出芽的酵母酿酒酵母放弃有丝分裂增殖并开始分化过程，通过减数分裂形成单倍体孢子。这个过程是由减数分裂特异性基因表达的级联波驱动的。早期减数分裂特异性基因在有丝分裂增殖过程中被 DNA 结合蛋白 Ume6 与阻遏物 Rpd3 和 Sin3 抑制。减数分裂特异性转录因子 Ime1 的表达导致早期减数分裂特异性基因的激活。我们研究了 Ume6 在孢子形成细胞中的稳定性和启动子占有率，并确定当这些基因被激活时，它仍然与早期减数分裂特异性基因启动子结合。此外，我们发现在反式激活因子 Ime1 加入复合物后，阻遏物 Rpd3 仍然与 Ume6 相关，并且 SAGA 复合物的 Gcn5 和 Tra1 组分以依赖 Ime1 的方式与 IME2 的启动子结合，以诱导早期减数分裂特异性的转录基因。我们的调查支持一个模型，其中 Ume6 提供了一个平台，允许招募激活和抑制因子来协调酿酒酵母中早期减数分裂特异性基因的表达。