Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA.
Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Mol Cell. 2014 Aug 7;55(3):361-71. doi: 10.1016/j.molcel.2014.06.008. Epub 2014 Jul 4.
DNA methylation patterns are dynamically controlled by DNA methylation and active DNA demethylation, but the mechanisms of regulation of active DNA demethylation are not well understood. Through forward genetic screens for Arabidopsis mutants showing DNA hypermethylation at specific loci and increased silencing of reporter genes, we identified IDM2 (increased DNA methylation 2) as a regulator of DNA demethylation and gene silencing. IDM2 dysfunction causes DNA hypermethylation and silencing of reporter genes and some endogenous genes. These effects of idm2 mutations are similar to those of mutations in IDM1, a regulator of active DNA demethylation. IDM2 encodes an α-crystallin domain protein in the nucleus. IDM2 and IDM1 interact physically and partially colocalize at discrete subnuclear foci. IDM2 is required for the full activity of H3K18 acetylation but not H3K23 acetylation of IDM1 in planta. Our results suggest that IDM2 functions in active DNA demethylation and in antisilencing by regulating IDM1.
DNA 甲基化模式受 DNA 甲基化和活性 DNA 去甲基化的动态控制,但活性 DNA 去甲基化的调节机制尚不清楚。通过正向遗传学筛选,我们在拟南芥突变体中鉴定到 IDM2(增加的 DNA 甲基化 2)是 DNA 去甲基化和基因沉默的调节因子。IDM2 功能障碍导致报告基因和一些内源性基因的 DNA 超甲基化和沉默。idm2 突变的这些影响与活性 DNA 去甲基化调节因子 IDM1 的突变相似。IDM2 编码核内的α-晶状体蛋白结构域蛋白。IDM2 和 IDM1 物理相互作用,并在离散的亚核焦点部分共定位。IDM2 是 IDM1 在体内 H3K18 乙酰化但不是 H3K23 乙酰化的完全活性所必需的。我们的结果表明,IDM2 通过调节 IDM1 来发挥活性 DNA 去甲基化和抗沉默的作用。