Chromatin attachment to the nuclear matrix represses hypocotyl elongation in Arabidopsis thaliana. Chromatin attachment to the nuclear matrix represses hypocotyl elongation in Arabidopsis thaliana

The nuclear matrix was identified as a nuclear fraction in eukaryotic cells that offers a supporting scaffold for chromatin. While the structure is known in plant nuclei for decades, the distribution of regions attaching at plant nuclei, and how the nuclear matrix influences chromatin status is largely unkown. Here, we identify novel proteins, FRS7 (FAR1 RELATED SEQUENCE 7) and FRS12, attaching chromatin regions at the nuclear matrix in Arabidopsis thaliana. We found the above two proteins cooperate with AHL22 (AT-hook Motif Nuclear Localized 22) in repress hypocotyl elongation, by recruiting chromatin regions and histone deacetylases to the nuclear matrix and silence the genes. These findings shed light on understanding regulation and roles of the nuclear matrix influence in epigenetic and transcriptional regulation in Arabidopsis. Overall design: We analyze the function of nuclear matrix attachment in transcriptional regulation by RNAseq and MARseq

核基质（nuclear matrix）被鉴定为真核细胞中为染色质提供支撑支架的核组分。尽管该结构在植物细胞核中的发现已有数十年历史，但植物细胞核内染色质附着区域的分布特征，以及核基质如何影响染色质状态，在很大程度上仍未明确。本研究在拟南芥（Arabidopsis thaliana）中鉴定到两种新型蛋白质——FRS7（FAR1相关序列7，FAR1 RELATED SEQUENCE 7）与FRS12，它们可将染色质区域锚定至核基质。研究发现，上述两种蛋白质与AHL22（AT钩基序核定位蛋白22，AT-hook Motif Nuclear Localized 22）协同发挥作用，通过将染色质区域与组蛋白去乙酰化酶招募至核基质并沉默靶基因，进而抑制下胚轴伸长。上述研究结果为理解核基质在拟南芥表观遗传与转录调控中的作用及调控机制提供了新的见解。整体实验设计：本研究通过RNA测序（RNAseq）与基质附着区域测序（MARseq），分析核基质附着在转录调控中的功能。