DOT1—— 一类新的组蛋白赖氨酸甲基转移酶

组蛋白甲基化是一种重要的组蛋白共价修饰, 在染色质结构和基因表达的调控过程中起着重要的、多样化的作用。DOT1催化核心球体部位的组蛋白H3第79位赖氨酸(H3K79)使其发生甲基化, 是首个被发现的无SET结构域的组蛋白赖氨酸甲基转移酶, 代表了一类新的组蛋白赖氨酸甲基转移酶。DOT1及H3K79甲基化的特点决定了其可能具有重要的、特殊的生物学功能。文章重点综述了DOT1蛋白的结构及特点, DOT1及H3K79甲基化的生物学功能以及组蛋白泛素化修饰对H3K79甲基化的反式调控。

DOT1: A distinct class of histone lysine methyltransferase

Lysine methylation is an important covalent modification of histone and has fundamental and divers roles in biological processes including regulation of chromatin structure dynamics and gene expression.Recently,a distinct class of histone lysine methyltransferase DOT1 was found to methylate histone H3 lysine79(H3K79) residue,which is located on the accessible face of the core nucleosome.The DOT1 proteins do not contain a SET domain,a conserved sequence motif found in all previously characterized histone H3 lysine methyltransferases that act on the histone N-termianl tail.The char-acteristics of DOT1 proteins and H3K79 methylation suggest that they may have important and characteristic functions.Here,we summarize recent advances in specific structure of DOT1 protein,biological functions of DOT1 proteins and H3K79 methylation and trans-histone regulatory1 between histone H2B ubiquitination and H3K79 methylation.