Sun Yuanyi, Xie Qijun, Chu Huaixue, Lv Bin, Xie Linan, Zhang Qingzhu
College of Life Science, Northeast Forestry University, Harbin 150040, China.
Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Ecology, Northeast Forestry University, Harbin 150040, China.
Int J Mol Sci. 2025 May 19;26(10):4845. doi: 10.3390/ijms26104845.
Chromatin remodeling factors efficiently and precisely establish, maintain, regulate, and distinguish between chromatin states in eukaryotes. DECREASE in DNA METHYLATION 1 (DDM1) is an important heterochromatin remodeling factor in plants that is responsible for maintaining heterochromatin DNA methylation and suppressing most transposable elements. Previous studies have predominantly focused on the effects of DDM1 on chromatin, with only a few focusing on its remodeling mechanisms. However, recent studies have greatly advanced understanding of the remodeling functions of DDM1 and, in particular, have clarified the mechanisms involved. In this review, we discuss the newly identified remodeling functions and mechanisms of DDM1. As DDM1 is closely involved in histone variant exchange, we first introduce the main histone variants associated with chromatin states in plants. Next, we focus on how DDM1 promotes the deposition of specific histone variants and describe its other remodeling functions. We propose that the core function of DDM1 is the regulation of histone variant distribution. DDM1 maintains heterochromatin by regulating the deposition of H2A and H3 variants, particularly by facilitating the exchange of specific histone variants.
染色质重塑因子能够高效且精确地在真核生物中建立、维持、调节染色质状态并区分不同的染色质状态。DNA甲基化降低1（DDM1）是植物中一种重要的异染色质重塑因子，负责维持异染色质DNA甲基化并抑制大多数转座元件。以往的研究主要集中在DDM1对染色质的影响上，只有少数研究关注其重塑机制。然而，最近的研究极大地推进了对DDM1重塑功能的理解，特别是阐明了其中涉及的机制。在本综述中，我们讨论了DDM1新发现的重塑功能和机制。由于DDM1与组蛋白变体交换密切相关，我们首先介绍与植物染色质状态相关的主要组蛋白变体。接下来，我们重点关注DDM1如何促进特定组蛋白变体的沉积，并描述其其他重塑功能。我们认为DDM1的核心功能是调节组蛋白变体的分布。DDM1通过调节H2A和H3变体的沉积来维持异染色质，特别是通过促进特定组蛋白变体的交换。
