Obermeyer Simon, Stöckl Richard, Schnekenburger Tobias, Moehle Christoph, Schwartz Uwe, Grasser Klaus D
Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Regensburg, Germany.
Center of Excellence for Fluorescent Bioanalytics (KFB), University of Regensburg, Regensburg, Germany.
Front Plant Sci. 2022 Sep 29;13:974625. doi: 10.3389/fpls.2022.974625. eCollection 2022.
Transcript elongation by RNA polymerase II (RNAPII) is dynamic and highly regulated, thereby contributing to the implementation of gene expression programs during plant development or in response to environmental cues. The heterohexameric polymerase-associated factor 1 complex (PAF1C) stabilizes the RNAPII elongation complex promoting efficient transcript synthesis. In addition, PAF1C links transcriptional elongation with various post-translational histone modifications at transcribed loci. We have exposed mutants deficient in the PAF1C subunits ELF7 or CDC73 to elevated NaCl concentrations to provoke a transcriptional response. The growth of plants was reduced relative to that of wildtype under these challenging conditions, whereas plants exhibited rather enhanced tolerance. Profiling of the transcriptional changes upon NaCl exposure revealed that responded similar to wildtype. Relative to wildtype and , the transcriptional response of plants was severely reduced in accord with their greater susceptibility to NaCl. The data also imply that CDC73 is more relevant for the transcription of longer genes. Despite the fact that both ELF7 and CDC73 are part of PAF1C the strikingly different transcriptional response of the mutants upon NaCl exposure suggests that the subunits have (partially) specific functions.
RNA聚合酶II（RNAPII）介导的转录延伸是动态且受到高度调控的，从而有助于在植物发育过程中或响应环境信号时实现基因表达程序。异源六聚体聚合酶相关因子1复合物（PAF1C）可稳定RNAPII延伸复合物，促进高效的转录本合成。此外，PAF1C将转录延伸与转录位点处的各种翻译后组蛋白修饰联系起来。我们将PAF1C亚基ELF7或CDC73缺陷的突变体暴露于升高的NaCl浓度下，以引发转录反应。在这些具有挑战性的条件下，突变体植株的生长相对于野生型有所降低，而ELF7缺陷型植株表现出更强的耐受性。对NaCl处理后的转录变化进行分析发现，CDC73缺陷型植株的反应与野生型相似。相对于野生型和ELF7缺陷型植株，CDC73缺陷型植株的转录反应严重降低，这与它们对NaCl的更高敏感性一致。数据还表明，CDC73与较长基因的转录更相关。尽管ELF7和CDC73都是PAF1C的组成部分，但突变体在NaCl处理后的转录反应却截然不同，这表明这些亚基具有（部分）特定功能。
