组蛋白甲基转移酶引导不同程度的甲基化以界定不同的染色质结构域。

Histone methyltransferases direct different degrees of methylation to define distinct chromatin domains.

作者信息

Rice Judd C, Briggs Scott D, Ueberheide Beatrix, Barber Cynthia M, Shabanowitz Jeffrey, Hunt Donald F, Shinkai Yoichi, Allis C David

机构信息

Department of Biochemistry and Molecular Genetics, University of Virginia Health System, University of Virginia, Charlottesville, VA 22908, USA.

出版信息

Mol Cell. 2003 Dec;12(6):1591-8. doi: 10.1016/s1097-2765(03)00479-9.

DOI:10.1016/s1097-2765(03)00479-9

PMID:14690610

Abstract

The functional significance of mono-, di-, and trimethylation of lysine residues within histone proteins remains unclear. Antibodies developed to selectively recognize each of these methylated states at histone H3 lysine 9 (H3 Lys9) demonstrated that mono- and dimethylation localized specifically to silent domains within euchromatin. In contrast, trimethylated H3 Lys9 was enriched at pericentric heterochromatin. Enzymes known to methylate H3 Lys9 displayed remarkably different enzymatic properties in vivo. G9a was responsible for all detectable H3 Lys9 dimethylation and a significant amount of monomethylation within silent euchromatin. In contrast, Suv39h1 and Suv39h2 directed H3 Lys9 trimethylation specifically at pericentric heterochromatin. Thus, different methylated states of H3 Lys9 are directed by specific histone methyltransferases to "mark" distinct domains of silent chromatin.

摘要

组蛋白中赖氨酸残基的单甲基化、二甲基化和三甲基化的功能意义仍不清楚。开发出的用于选择性识别组蛋白H3赖氨酸9（H3 Lys9）处这些甲基化状态的抗体表明，单甲基化和二甲基化特异性定位于常染色质内的沉默结构域。相比之下，三甲基化的H3 Lys9在着丝粒周围异染色质中富集。已知使H3 Lys9甲基化的酶在体内表现出显著不同的酶学特性。G9a负责沉默常染色质内所有可检测到的H3 Lys9二甲基化以及大量单甲基化。相比之下，Suv39h1和Suv39h2专门指导H3 Lys9在着丝粒周围异染色质处的三甲基化。因此，H3 Lys9的不同甲基化状态由特定的组蛋白甲基转移酶引导，以“标记”沉默染色质的不同结构域。