Histone H2B monoubiquitination is required to reach maximal transcript levels of circadian clock genes in Arabidopsis
Histone H2B monoubiquitination is required to reach maximal transcript levels of circadian clock genes in Arabidopsis
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DOI：
10.1111/j.1365-313x.2012.05071.x
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发表时间：
2012-10-01
期刊：
影响因子：
7.2
通讯作者：
Van Lijsebettens, Mieke
中科院分区：
文献类型：
--
作者：
Himanen, Kristiina;Woloszynska, Magdalena;Van Lijsebettens, Mieke
以前，我们确定组蛋白MONOUBIQUITINATION 1（HUB 1）作为一种非常规的泛素E3连接酶，不参与蛋白质降解，但在组蛋白H2 B修饰，涉及在植物中的转录激活。HUB 1介导的基因表达调控在细胞周期、休眠、开花时间和防御反应等周期性和诱导性过程中发挥作用。在这里，我们确定了集线器1 -1突变对一组昼夜诱导的生物钟基因表达的影响，这些基因是从集线器1 -1突变体和HUB 1过表达系之间的比较微阵列分析中鉴定的。hub 1 -1突变降低了许多诱导的时钟基因表达峰的幅度，以及与编码区相关的HUB 1介导的组蛋白H2 BUb和H3 K4 Me 3标记，表明HUB 1在促进植物转录延伸中的作用。此外，hub 1 -1和elongata（elo）之间的双突变体表现出胚胎致死表型，表明协同遗传相互作用。双突变胚胎在鱼雷期停滞，这意味着组蛋白遍在蛋白化和乙酰化标记对于激活多个途径中靶基因的表达至关重要。
Previously, we identified HISTONE MONOUBIQUITINATION1 (HUB1) as an unconventional ubiquitin E3 ligase that is not involved in protein degradation but in the histone H2B modification that is implicated in transcriptional activation in plants. HUB1-mediated regulation of gene expression played a role in periodic and inducible processes such as the cell cycle, dormancy, flowering time and defense responses. Here, we determined the effects of the hub1-1 mutation on expression of a set of diurnally induced circadian clock genes identified from a comparative microarray analysis between the hub1-1 mutant and an HUB1 over-expression line. The hub1-1 mutation reduced the amplitudes of a number of induced clock gene expression peaks, as well as the HUB1-mediated histone H2BUb and H3K4Me3 marks associated with the coding regions, suggesting a role for HUB1 in facilitating transcriptional elongation in plants. Furthermore, double mutants between hub1-1 and elongata (elo) showed an embryo-lethal phenotype, indicating a synergistic genetic interaction. The double mutant embryos arrested at the torpedo stage, implying that together histone ubiquitination and acetylation marks are essential to activate expression of target genes in multiple pathways.