Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany.
Plant J. 2024 May;118(3):645-656. doi: 10.1111/tpj.16115. Epub 2023 Feb 12.
Transcriptional elongation by RNA polymerase II (RNAPII) through chromatin is a dynamic and highly regulated step of eukaryotic gene expression. A combination of transcript elongation factors (TEFs) including modulators of RNAPII activity and histone chaperones facilitate efficient transcription on nucleosomal templates. Biochemical and genetic analyses, primarily performed in Arabidopsis, provided insight into the contribution of TEFs to establish gene expression patterns during plant growth and development. In addition to summarising the role of TEFs in plant gene expression, we emphasise in our review recent advances in the field. Thus, mechanisms are presented how aberrant intragenic transcript initiation is suppressed by repressing transcriptional start sites within coding sequences. We also discuss how transcriptional interference of ongoing transcription with neighbouring genes is prevented. Moreover, it appears that plants make no use of promoter-proximal RNAPII pausing in the way mammals do, but there are nucleosome-defined mechanism(s) that determine the efficiency of mRNA synthesis by RNAPII. Accordingly, a still growing number of processes related to plant growth, development and responses to changing environmental conditions prove to be regulated at the level of transcriptional elongation.
RNA 聚合酶 II（RNAPII）在染色质上的转录延伸是真核生物基因表达的一个动态且高度调控的步骤。转录延伸因子（TEFs）的组合，包括 RNAPII 活性调节剂和组蛋白伴侣，促进了核小体模板上的有效转录。主要在拟南芥中进行的生化和遗传分析，深入了解了 TEFs 在植物生长和发育过程中建立基因表达模式的贡献。除了总结 TEFs 在植物基因表达中的作用外，我们在综述中强调了该领域的最新进展。因此，本文介绍了如何通过抑制编码序列内的转录起始位点来抑制异常基因内转录起始的机制。我们还讨论了如何防止正在进行的转录与相邻基因之间的转录干扰。此外，似乎植物不像哺乳动物那样利用启动子近端的 RNAPII 暂停，但存在核小体定义的机制来确定 RNAPII 合成 mRNA 的效率。因此，越来越多与植物生长、发育和对环境变化的反应相关的过程被证明是在转录延伸水平上受到调控的。
