Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.
Cell Rep. 2024 Aug 27;43(8):114593. doi: 10.1016/j.celrep.2024.114593. Epub 2024 Aug 4.
We describe a time-resolved nascent single-cell RNA sequencing (RNA-seq) approach that measures gene-specific transcriptional noise and the fraction of active genes in S. cerevisiae. Most genes are expressed with near-constitutive behavior, while a subset of genes show high mRNA variance suggestive of transcription bursting. Transcriptional noise is highest in the cofactor/coactivator-redundant (CR) gene class (dependent on both SAGA and TFIID) and strongest in TATA-containing CR genes. Using this approach, we also find that histone gene transcription switches from a low-level, low-noise constitutive mode during M and M/G1 to an activated state in S phase that shows both an increase in the fraction of active promoters and a switch to a noisy and bursty transcription mode. Rapid depletion of cofactors SAGA and MED Tail indicates that both factors play an important role in stimulating the fraction of active promoters at CR genes, with a more modest role in transcriptional noise.
我们描述了一种时间分辨的新生单细胞 RNA 测序（RNA-seq）方法，该方法可测量 S. cerevisiae 中基因特异性转录噪声和活性基因的分数。大多数基因的表达具有近乎组成型的行为，而一部分基因的 mRNA 方差较高，提示转录爆发。转录噪声在共因子/共激活因子冗余（CR）基因类中最高（依赖于 SAGA 和 TFIID），并且在含有 TATA 的 CR 基因中最强。使用这种方法，我们还发现组蛋白基因转录从 M 和 M/G1 期间的低水平、低噪声组成型模式切换到 S 期的激活状态，这表现为活性启动子的分数增加以及向嘈杂和爆发性转录模式的转变。共因子 SAGA 和 MED Tail 的快速耗竭表明，这两个因子都在刺激 CR 基因的活性启动子分数方面发挥重要作用，而在转录噪声方面的作用则较为适度。
