Fong Paulus M, Tian Lu, Chen Z Jeffrey
Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA.
Cell Res. 2006 May;16(5):479-88. doi: 10.1038/sj.cr.7310059.
Arabidopsis thaliana histone deacetylase 1 (AtHD1 or AtHDA19), a homolog of yeast RPD3, is a global regulator of many physiological and developmental processes in plants. In spite of the genetic evidence for a role of AtHD1 in plant gene regulation and development, the biochemical and cellular properties of AtHD1 are poorly understood. Here we report cellular localization patterns of AtHD1 in vivo and histone deacetylase activity in vitro. The transient and stable expression of a green fluorescent protein (GFP)-tagged AtHD1 in onion cells and in roots, seeds and leaves of the transgenic Arabidopsis, respectively, revealed that AtHD1 is localized in the nucleus presumably in the euchromatic regions and excluded from the nucleolus. The localization patterns of AtHD1 are different from those of AtHD2 and AtHDA6 that are involved in nucleolus formation and silencing of transgenes and repeated DNA elements, respectively. In addition, a histone deacetylase activity assay showed that the recombinant AtHD1 produced in bacteria demonstrated a specific histone deacetylase activity in vitro. The data suggest that AtHD1 is a nuclear protein and possesses histone deacetylase activities responsible for global transcriptional regulation important to plant growth and development.
拟南芥组蛋白去乙酰化酶1（AtHD1或AtHDA19）是酵母RPD3的同源物，是植物中许多生理和发育过程的全局调节因子。尽管有遗传证据表明AtHD1在植物基因调控和发育中起作用，但对AtHD1的生化和细胞特性了解甚少。在这里，我们报告了AtHD1在体内的细胞定位模式和体外的组蛋白去乙酰化酶活性。绿色荧光蛋白（GFP）标记的AtHD1分别在洋葱细胞以及转基因拟南芥的根、种子和叶片中的瞬时和稳定表达表明，AtHD1定位于细胞核中，可能位于常染色质区域，且被排除在核仁之外。AtHD1的定位模式与分别参与转基因和重复DNA元件的核仁形成和沉默的AtHD2和AtHDA6不同。此外，组蛋白去乙酰化酶活性测定表明，细菌中产生的重组AtHD1在体外表现出特异性的组蛋白去乙酰化酶活性。数据表明，AtHD1是一种核蛋白，具有负责对植物生长和发育重要的全局转录调控的组蛋白去乙酰化酶活性。
