Plant Elongator regulates auxin-related genes during RNA polymerase II transcription elongation
Plant Elongator regulates auxin-related genes during RNA polymerase II transcription elongation
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DOI：
10.1073/pnas.0913559107
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发表时间：
2010-01-26
影响因子：
11.1
通讯作者：
Van Lijsebettens, Mieke
中科院分区：
文献类型：
--
作者：
Nelissen, Hilde;De Groeve, Steven;Van Lijsebettens, Mieke
在真核生物中，蛋白质编码基因的转录受到组蛋白翻译后修饰的强烈调控，组蛋白的翻译后修饰会影响RNA聚合酶II （RNAPII）对DNA的可及性。细长体复合体最初在酵母中被鉴定为一种组蛋白乙酰转移酶（HAT）复合体，可激活rnapii介导的转录。在拟南芥中，由于细胞增殖减少而导致叶片和初生根生长下降的延长体突变体elo1、elo2和elo3分别鉴定出了酵母延长体复合物Elp4、Elp1和Elp3的同源物。在这里，我们展示了从植物细胞培养物中纯化的细长复合物作为一个六组分复合物。植物伸长体在转录伸长中的作用得到了HAT酶ELO3与常染色质和RNAPII磷酸化形式共定位的支持，并且在ELO3突变体中减少了SHORT HYPOCOTYL 2生长素抑制因子和LAX2生长素内流载体基因编码区域的组蛋白H3赖氨酸14乙酰化，降低了表达水平。在elo突变体的转录组中，其他生长素相关基因被下调，但未被拉长者HAT活性靶向，显示出靶基因选择的特异性。生长素相关表型和标记基因分析显示生物学相关性明显。乙烯和茉莉酸信号和非生物胁迫响应在elo转录组中上调，这可能与elo多性表型有关。因此，尽管伸长体及其底物的结构是保守的，但靶基因的选择出现了分化，这表明生长素的信号传导和内流受到染色质的控制。
In eukaryotes, transcription of protein-encoding genes is strongly regulated by posttranslational modifications of histones that affect the accessibility of the DNA by RNA polymerase II (RNAPII). The Elongator complex was originally identified in yeast as a histone acetyltransferase (HAT) complex that activates RNAPII-mediated transcription. In Arabidopsis thaliana, the Elongator mutants elo1, elo2, and elo3 with decreased leaf and primary root growth due to reduced cell proliferation identified homologs of components of the yeast Elongator complex, Elp4, Elp1, and Elp3, respectively. Here we show that the Elongator complex was purified from plant cell cultures as a six-component complex. The role of plant Elongator in transcription elongation was supported by colocalization of the HAT enzyme, ELO3, with euchromatin and the phosphorylated form of RNAPII, and reduced histone H3 lysine 14 acetylation at the coding region of the SHORT HYPOCOTYL 2 auxin repressor and the LAX2 auxin influx carrier gene with reduced expression levels in the elo3 mutant. Additional auxin-related genes were down-regulated in the transcriptome of elo mutants but not targeted by the Elongator HAT activity showing specificity in target gene selection. Biological relevance was apparent by auxin-related phenotypes and marker gene analysis. Ethylene and jasmonic acid signaling and abiotic stress responses were up-regulated in the elo transcriptome and might contribute to the pleiotropic elo phenotype. Thus, although the structure of Elongator and its substrate are conserved, target gene selection has diverged, showing that auxin signaling and influx are under chromatin control.