RNA polymerase II (RNAPII) transcription is crucial for gene expression. RNAPII density peaks at gene boundaries, associating these key regions for gene expression control with limited RNAPII movement. The connections between RNAPII transcription speed and gene regulation in multicellular organisms are poorly understood. Here, we directly modulate RNAPII transcription speed by point mutations in the second largest subunit of RNAPII in Arabidopsis thaliana. A RNAPII mutation predicted to decelerate transcription is inviable, while accelerating RNAPII transcription confers phenotypes resembling auto-immunity. Nascent transcription profiling revealed that RNAPII complexes with accelerated transcription clear stalling sites at both gene ends, resulting in read-through transcription. The accelerated transcription mutant NRPB2-Y732F exhibits increased association with 5' splice site (5'SS) intermediates and enhanced splicing efficiency. Our findings highlight potential advantages of RNAPII stalling through local reduction in transcription speed to optimize gene expression for the development of multicellular organisms.

中文翻译：

---

基因边界转录速度控制的有机益处。

RNA 聚合酶 II (RNAPII) 转录对于基因表达至关重要。RNAPII 密度在基因边界处达到峰值，将这些基因表达控制的关键区域与有限的 RNAPII 运动联系起来。多细胞生物体中 RNAPII 转录速度与基因调控之间的联系尚不清楚。在这里，我们通过拟南芥RNAPII第二大亚基的点突变直接调节RNAPII转录速度。预计会减慢转录速度的 RNAPII 突变是不可行的，而加速 RNAPII 转录则会产生类似于自身免疫的表型。新生转录分析显示，具有加速转录的 RNAPII 复合物清除了基因两端的停滞位点，从而导致通读转录。加速转录突变体 NRPB2-Y732F 表现出与 5' 剪接位点 (5'SS) 中间体的关联增加和剪接效率增强。我们的研究结果强调了 RNAPII 通过局部降低转录速度来优化基因表达以促进多细胞生物发育的潜在优势。