Alterations of Lysine Modifications on the Histone H3 N-Tail under Drought Stress Conditions in Arabidopsis thaliana
Alterations of Lysine Modifications on the Histone H3 N-Tail under Drought Stress Conditions in Arabidopsis thaliana
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DOI：
10.1093/pcp/pcn133
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发表时间：
2008-10-01
影响因子：
4.9
通讯作者：
Seki, Motoaki
中科院分区：
文献类型：
--
作者：
Kim, Jong-Myong;To, Taiko Kim;Seki, Motoaki
组蛋白N-尾的翻译后修饰影响真核基因活性。在拟南芥中，组蛋白修饰水平与春化和开花过程中的基因激活和抑制相关，但非生物胁迫下组蛋白修饰状态和核小体结构的变化信息很少。我们通过染色质免疫沉淀分析确定了在干旱胁迫条件下，4个拟南芥干旱胁迫诱导基因RD 29 A、RD 29 B、RD 20和RAP 2.4的核小体占据率和组蛋白H3 N-尾中H3 K4 me 3、H3 K9 ac、H3 K14 ac、H3 K23 ac和H3 K27 ac水平的时空变化。我们发现了两种类型的核小体占据功能的调节机制在干旱胁迫响应。对于RD 29 A和RD 29 B基因，启动子区的核小体占有率较低，与编码区相比，在干旱胁迫下没有发生明显的核小体丢失。与此相反，RD 20和RAP 2.4基因的核小体密度在干旱胁迫下逐渐降低。在所有四个基因中，H3 K4 me 3和H3 K9 ac的富集与响应于干旱胁迫的基因激活相关。有趣的是，H3 K4 me 3的建立发生在RNAPII在RD 29 A和RAP 2.4的编码区上积累之后。H3 K23 ac和H3 K27 ac在RD 29 B、RD 20和RAP 2.4的编码区上富集，而在RD 29 A的编码区上不富集。我们的研究结果表明，组蛋白修饰的H3 N-尾改变与基因激活的编码区的干旱胁迫响应基因在干旱胁迫条件下，几种模式的核小体变化功能的干旱胁迫响应。
Post-translational modification of histone N-tails affects eukaryotic gene activity. In Arabidopsis, the histone modification level correlates with gene activation and repression in vernalization and flowering processes, but there is little information on changes in histone modification status and nucleosome structure under abiotic stresses. We determined the temporal and spatial changes in nucleosome occupancy and levels of H3K4me3, H3K9ac, H3K14ac, H3K23ac and H3K27ac in the histone H3 N-tail on the regions of four Arabidopsis drought stress-inducible genes, RD29A, RD29B, RD20 and RAP2.4, under drought stress conditions by chromatin immunoprecipitation analysis. We found two types of regulatory mechanisms of nucleosome occupancy function in the drought stress response. For RD29A and RD29B genes, nucleosome occupancy of promoter regions is low compared with that of coding regions, and no notable nucleosome loss occurs under drought stress. In contrast, nucleosome density is gradually decreased in response to drought stress on RD20 and RAP2.4 genes. Enrichments of H3K4me3 and H3K9ac correlate with gene activation in response to drought stress in all four genes. Interestingly, establishment of H3K4me3 occurs after accumulation of RNAPII on the coding regions of RD29A and RAP2.4. Enrichment of H3K23ac and H3K27ac occurs in response to drought stress on the coding regions of RD29B, RD20 and RAP2.4, but not on the coding region of RD29A. Our results indicate that histone modifications on the H3 N-tail are altered with gene activation on the coding regions of drought stress-responsive genes under drought stress conditions and that several patterns of nucleosome changes function in the drought stress response.