Human histone demethylase LSD1 reads the histone code
Human histone demethylase LSD1 reads the histone code
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DOI：
10.1074/jbc.m509549200
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发表时间：
2005-12-16
影响因子：
4.8
通讯作者：
Mattevi, A
中科院分区：
文献类型：
--
作者：
Forneris, F;Binda, C;Mattevi, A
人组蛋白去甲基化酶LSD1是一种黄素依赖型胺氧化酶，它催化从组蛋白H3的单甲基化和双甲基化的Lys(4)上特异性去除甲基基团。H3的N末端尾部会发生各种共价修饰，LSD1生物学中的一个基本问题是这些表观遗传标记如何影响去甲基化酶的活性。我们发现LSD1对H3的单甲基化或双甲基化的Lys(4)没有强烈的偏好。底物识别不限于Lys(4)附近的残基，但它需要一个由H3的N末端20个氨基酸组成的足够长的肽段。静电相互作用是蛋白质 - 底物识别的一个重要因素，这从Km对离子强度的高度敏感性可以看出。我们研究了LSD1在同一肽底物上存在第二种修饰时对Lys4去甲基化的能力。Lys(9)的甲基化不影响酶催化。相反，Lys9的乙酰化导致Km值几乎增加6倍，而Ser(10)的磷酸化则完全消除活性。LSD1被一种去甲基化的肽抑制，抑制常数为1.8μM，这表明LSD1可以独立于Lys(4)的甲基化与H3结合。LSD1是一种染色质修饰酶，它能够读取组蛋白N末端尾部的不同表观遗传标记，并可作为一个对接模块，用于稳定染色质上相关的辅阻遏物复合物。
Human histone demethylase LSD1 is a flavin-dependent amine oxidase that catalyzes the specific removal of methyl groups from mono- and dimethylated Lys(4) of histone H3. The N-terminal tail of H3 is subject to various covalent modifications, and a fundamental question in LSD1 biology is how these epigenetic marks affect the demethylase activity. We show that LSD1 does not have a strong preference for mono- or dimethylated Lys(4) of H3. Substrate recognition is not confined to the residues neighboring Lys(4), but it requires a sufficiently long peptide segment consisting of the N-terminal 20 amino acids of H3. Electrostatic interactions are an important factor in protein-substrate recognition, as indicated by the high sensitivity of Km to ionic strength. We have probed LSD1 for its ability to demethylate Lys4 in presence of a second modification on the same peptide substrate. Methylation of Lys(9) does not affect enzyme catalysis. Conversely, Lys9 acetylation causes an almost 6-fold increase in the Km value, whereas phosphorylation of Ser(10) totally abolishes activity. LSD1 is inhibited by a demethylated peptide with an inhibition constant of 1.8 mu M, suggesting that LSD1 can bind to H3 independently of Lys(4) methylation. LSD1 is a chromatin-modifying enzyme, which is able to read different epigenetic marks on the histone N-terminal tail and can serve as a docking module for the stabilization of the associated corepressor complex(es) on chromatin.