COP1 controls light-dependent chromatin remodeling in Arabidopsis [ChIP-Seq]. COP1 controls light-dependent chromatin remodeling in Arabidopsis [ChIP-Seq]

Light is an environmental factor that influences various aspects of plant development. Phytochromes (phys) as light sensors regulate myriads of downstream genes in response to changes in environmental factors. VIL1 (VIN3-LIKE 1)/VERNALIZATION 5 (VRN5), a Polycomb Repressive Complex 2 (PRC2) - associated protein, mediates vernalization pathway. VIL1 directly interacts with phyB and regulates photomorphogenesis through the formation of repressive chromatin loops at downstream growth-promoting genes in response to light. CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) is an E3 ligase for a number of substrates in light signaling, acting as a central repressor of photomorphogenesis. Here, we show that VIL1 is a substrate of COP1 and COP1 degrades VIL1 through the ubiquitin/26S proteosome system (UPS) in the dark. Our study illustrates that COP1 controls light-dependent formation of chromatin loop by regulating the stability of VIL1 and limits a repressive histone modification to fine-tune expressions of growth-promoting genes during photomorphogenesis. We performed Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone modifications H3K27me3 in five Arabidopsis genotypes (Col-0, vil1-1, cop1-4, vil1-1cop1-4 and hy5-215). Overall design: Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone modifications H3K27me3 in five Arabidopsis genotypes (Col-0, vil1-1, cop1-4, vil1-1cop1-4 and hy5-215).

光作为环境因子，可调控植物发育的多个方面。光敏色素（phytochromes, phys）作为光受体，能够响应环境变化并调控大量下游基因的表达。VIL1（VIN3-LIKE 1）/春化基因5（VERNALIZATION 5, VRN5）是多梳抑制复合体2（Polycomb Repressive Complex 2, PRC2）的相关蛋白，介导春化信号通路。VIL1可直接与phyB互作，并通过在下游促生长基因位点形成抑制性染色质环，响应光信号调控植物光形态建成。组成型光形态建成1（CONSTITUTIVELY PHOTOMORPHOGENIC 1, COP1）是光信号通路中多种底物的E3泛素连接酶，作为光形态建成的核心抑制因子发挥功能。本研究证实VIL1是COP1的底物，COP1可在黑暗环境中通过泛素-26S蛋白酶体系统（ubiquitin/26S proteosome system, UPS）降解VIL1。本研究阐明，COP通过调控VIL1的蛋白稳定性，控制光依赖的染色质环形成，并限制抑制性组蛋白修饰的范围，从而在光形态建成过程中精细调控促生长基因的表达水平。我们针对5种拟南芥基因型（Col-0、vil1-1、cop1-4、vil1-1cop1-4和hy5-215）的组蛋白修饰H3K27me3开展了染色质免疫沉淀测序（Chromatin immunoprecipitation DNA-sequencing, ChIP-seq）。实验整体设计：针对5种拟南芥基因型（Col-0、vil1-1、cop1-4、vil1-1cop1-4和hy5-215）的组蛋白修饰H3K27me3进行染色质免疫沉淀测序（ChIP-seq）。