Histone(组蛋白) Deacetylases SRT1 and SRT2 Interact with ENAP1 to Mediate Ethylene-Induced Transcriptional RepressionFan Zhang, Likai Wang, Eun Esther Ko, Kevin Shao, Hong Qiao Published January 2018. DOI: http://dx./10.1105/tpc.17.00671 来自：美国德克萨斯大学奥斯汀分校 AbstractEthylene(乙烯) plays pleiotropic(多效性的) roles in plant growth, plant development, and stress responses. Although the effects of ethylene on plants are well documented, little is known about molecular-level events that result in transcriptional repression(抑制) during the ethylene response. In this study, we found that two histone(组蛋白) deacetylases(脱乙酰酶), SRT1 and SRT2, interact with ENAP1, which associates with EIN2 in the nucleus(核). Genetic and transcriptome analyses revealed that SRT1 and SRT2 are required for negative regulation of certain ethylene-responsive genes. The acetylation(乙酰化作用) of HISTONE3 at K9 (H3K9Ac) is specifically regulated by SRT1 and SRT2 in ethylene-repressed genes. In addition, the srt1 srt2 double mutation in Arabidopsis thaliana suppresses both the ENAP1ox and the EIN3ox constitutive(基本的) ethylene response phenotypes(表型), and the ethylene-induced transcriptional repression observed in EIN3ox plants is derepressed(去阻遏) in the EIN3ox/srt1 srt2 mutant(突变体). SRT2 and ENAP1 both bind to promoter regions of genes negatively regulated by ethylene(乙烯), reducing H3K9Ac levels and resulting in transcriptional repression(抑制). This work establishes a mechanism by which histone(组蛋白) deacetylases(脱乙酰酶) SRT1 and SRT2 interact with ENAP1 to mediate transcriptional repression by regulating the levels of H3K9 acetylation(乙酰化作用) in the ethylene signaling. 乙烯在植物生长，植物发育和胁迫反应中起着多种作用。尽管乙烯对植物的影响已有文献报道，但对乙烯响应过程中导致转录抑制的分子水平事件知之甚少。在本研究中，我们发现两个组蛋白脱乙酰酶SRT1和SRT2与ENAP1相互作用，ENAP1与核内的EIN2相关联。遗传和转录组分析揭示SRT1和SRT2是负调控某些乙烯反应基因所必需的。 HISTONE3在K9（H3K9Ac）处的乙酰化受乙烯抑制基因中的SRT1和SRT2特异性调节。此外，拟南芥中的srt1 srt2双重突变抑制ENAP1ox和EIN3ox组成型乙烯响应表型，并且在EIN3ox植物中观察到的乙烯诱导的转录阻遏在EIN3ox / srt1 srt2突变体中被去阻遏。 SRT2和ENAP1都与受乙烯负调控的基因的启动子区域结合，降低H3K9Ac水平并导致转录抑制。这项工作建立了一个机制，其中组蛋白脱乙酰酶SRT1和SRT2与ENAP1相互作用，通过调节乙烯信号传导中H3K9乙酰化水平介导转录抑制。 ENAP1 Interacts with SRT1 and SRT2 in Vitro and in Vivo. srt1 srt2 Rescues the EIN3ox Phenotype. 欢迎点击「PaperRss」↑关注我们！ 2Plant cell| 通过HY5转录因子调控开放阅读中的远红光检测调节侧根发育Far-Red Light Detection in the Shoot Regulates Lateral Root Development through the HY5 Transcription Factor来自：荷兰乌特勒支大学生物系 AbstractPlants in dense vegetation(植被) compete for resources and detect competitors through reflection of far-red (FR) light from surrounding plants. This reflection causes a reduced red (R):FR ratio, which is sensed through phytochromes(光敏色素). Low R:FR induces shade avoidance(逃避) responses of the shoot and also changes the root system architecture, although this has received little attention so far. Here, we investigate the molecular mechanisms through which light detection in the shoot regulates root development in Arabidopsis thaliana. We do so using a combination of microscopy(显微镜检查), gene expression, and mutant(突变体) study approaches in a setup that allows root imaging without exposing the roots to light treatment. We show that low R:FR perception in the shoot decreases the lateral root (LR) density by inhibiting(抑制) LR emergence(出现). This decrease in LR emergence upon shoot FR enrichment(丰富) is regulated by phytochrome-dependent accumulation of the transcription factor ELONGATED HYPOCOTYL5 (HY5) in the LR primordia(原基). HY5 regulates LR emergence by decreasing the plasma membrane abundance of PIN-FORMED3 and LIKE-AUX1 3 auxin(植物生长素) transporters. Accordingly, FR enrichment reduces the auxin signal in the overlaying cortex(皮质) cells, and this reduces LR outgrowth. This shoot-to-root communication can help plants coordinate resource partitioning under competition for light in high density fields. Supplemental FR Experienced by the Shoot Leads to Reduced Lateral and Primary Root Growth. Enhanced Availability of HY5 under FR Enrichment Inhibits Lateral Root Emergence. 密集植物中的植物竞争资源，通过反射来自周围植物的远红光（FR）来检测竞争者。这种反射导致通过光敏色素感测到的红（R）：FR比率降低。低R：FR诱导枝条的遮荫避免响应，并且也改变了根系统结构，尽管迄今为止这已经不太受关注。在这里，我们调查的分子机制，通过其中光检测调节拟南芥根发育。我们这样做是在显微镜，基因表达和突变研究方法的结合下进行的，这种方法允许根成像，而不需要将根暴露于光照处理。我们表明，在射击低R：FR感知通过抑制LR的出现减少侧根（LR）密度。这种LR出现在枝条FR富集时的减少受到LR原基中转录因子ELONGATED HYPOCOTYL5（HY5）的光敏色素依赖性积累的调节。 HY5通过降低PIN-FORMED3和LIKE-AUX1 3生长素转运蛋白的质膜丰度来调节LR的出现。因此，富集FR减少了重叠的皮层细胞中的生长素信号，并且这降低了LR长出。这种基于对话的交流可以帮助植物在高密度领域的光照竞争下协调资源分配。 欢迎点击「PaperRss」↑关注我们！ 3Plant cell|拟南芥JMJ14-H3K4me3复合物的结构让我们对KDM5亚家族组蛋白去甲基化酶的底物特异性有深度了解。Structure of the Arabidopsis JMJ14-H3K4me3 Complex Provides Insight into the Substrate Specificity of KDM5 Subfamily Histone DemethylasesZhenlin Yang, Qi Qiu, Wei Chen, Bei Jia, Xiaomei Chen, Hongmiao Hu, Kaixuan He, Xian Deng, Sisi Li, W. Andy Tao, Xiaofeng Cao, Jiamu Du 来源： 1Jiamu Du 中科院上海植物逆境生物学研究中心杜嘉木研究组招聘博士后National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China 2 Xiaofeng Cao 曹晓风院士、中国科学院遗传与发育研究所研究员 University of Chinese Academy of Sciences, Beijing 100049, ChinaState Key Laboratory of Plant Genomics and National Center for Plant Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China 在染色质中，组蛋白甲基化影响动物和植物中多个过程的表观遗传调节，并受组蛋白甲基转移酶和组蛋白去甲基化酶的活性调节。含有jumonji结构域的组蛋白去甲基化酶具有不同的功能，可分为几个亚家族。在人类中，含有jumonji结构域的赖氨酸（K）特异性脱甲基酶5 / Jumonji和ARID结构域蛋白（KDM5 / JARID）亚家族脱甲基酶对组蛋白3赖氨酸4三甲基化（H3K4me3）是特异性的，并且是癌症治疗的重要药物靶标。在拟南芥中，KDM5 / JARID亚家族H3K4me3脱甲基化酶JUMONJI14（JMJ14）在开花，基因沉默和DNA甲基化中起重要作用。在这里，我们报告了无基质和结合形式的JMJ14催化结构域的晶体结构。结构显示jumonji和C5HC2结构域有助于H3R2和H3Q5的特异性识别以促进H3K4me3底物特异性。关键的酸性残基在植物和动物中是保守的，相应的突变会损害JMJ14和人KDM5B的酶活性，表明KDM5亚家族脱甲基酶与植物和动物共有的共同底物识别机制，并进一步说明设计人类靶向抑制剂的努力KDM5。 AbstractIn chromatin(核染色质), histone(组蛋白) methylation(甲基化) affects the epigenetic(后生的)regulation of multiple processes in animals and plants and is modulated(已调的) by the activities of histone methyltransferases(甲基转移酶) and histone demethylases. The jumonji domain-containing histone demethylases have diverse functions and can be classified into several subfamilies(亚科). In humans, the jumonji domain-containing Lysine(赖氨酸) (K)-Specific Demethylase 5/Jumonji and ARID Domain Protein (KDM5/JARID) subfamily demethylases are specific for histone 3 lysine 4 trimethylation (H3K4me3) and are important drug targets for cancer treatment. In Arabidopsis thaliana, the KDM5/JARID subfamily H3K4me3 demethylase JUMONJI14 (JMJ14) plays important roles in flowering, gene silencing, and DNA methylation. Here, we report the crystal structures of the JMJ14 catalytic domain in both substrate-free and bound forms. The structures reveal that the jumonji and C5HC2 domains contribute to the specific recognition of the H3R2 and H3Q5 to facilitate H3K4me3 substrate specificity(特异性). The critical acidic(酸的) residues are conserved(保存) in plants and animals with the corresponding mutations impairing(损害) the enzyme activity of both JMJ14 and human KDM5B, indicating a common substrate recognition mechanism for KDM5 subfamily demethylases shared by plants and animals and further informing efforts to design targeted inhibitors of human KDM5 欢迎点击「PaperRss」↑关注我们！ |
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