State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310027, China.
State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200433, China.
New Phytol. 2018 Oct;220(2):476-487. doi: 10.1111/nph.15311. Epub 2018 Jul 5.
DNA replication is a fundamental process for the faithful transmission of genetic information in all living organisms. Many endogenous and environmental signals impede fork progression during DNA synthesis, which induces replication errors and DNA replication stress. Chromatin remodeling factors regulate nucleosome occupancy and the histone composition of the nucleosome in chromatin; however, whether chromatin remodeling factors are involved in the DNA replication stress response in plants is unknown. We reveal that chromatin remodeling factor CHR18 plays important roles in DNA replication stress in Arabidopsis thaliana by interacting with the DNA replication protein RPA1A. According to the genetic analysis, the loss of function of either CHR18 or RPA1A confers a high sensitivity to DNA replication stress in Arabidopsis. CHR18 interacts with RPA1A in both yeast cells and tobacco epidermal cells. The coexpression of RPA1A and CHR18 enhances the accumulation of CHR18 in nuclear foci in plants. CHR18 is a typical nuclear-localized chromatin remodeling factor with ATPase activity. Our results demonstrate that during DNA synthesis in plants, RPA1A interacts with CHR18 and recruits CHR18 to nuclear foci to resolve DNA replication stress, which is important for cell propagation and root growth in Arabidopsis plants.
DNA 复制是所有生物中遗传信息忠实传递的基本过程。许多内源性和环境信号在 DNA 合成过程中阻碍叉的进展，从而诱导复制错误和 DNA 复制应激。染色质重塑因子调节核小体在染色质中的占据和组蛋白组成；然而，染色质重塑因子是否参与植物中的 DNA 复制应激反应尚不清楚。我们揭示染色质重塑因子 CHR18 通过与 DNA 复制蛋白 RPA1A 相互作用，在拟南芥中发挥重要作用，参与 DNA 复制应激反应。根据遗传分析，CHR18 或 RPA1A 的功能丧失赋予了拟南芥对 DNA 复制应激的高度敏感性。CHR18 在酵母细胞和烟草表皮细胞中均与 RPA1A 相互作用。RPA1A 和 CHR18 的共表达增强了 CHR18 在植物核焦点中的积累。CHR18 是一种具有 ATP 酶活性的典型核定位染色质重塑因子。我们的结果表明，在植物的 DNA 合成过程中，RPA1A 与 CHR18 相互作用，并将 CHR18 招募到核焦点以解决 DNA 复制应激，这对拟南芥植物的细胞增殖和根生长很重要。
