Different types of maize histone deacetylases are distinguished by a highly complex substrate and site specificity
Different types of maize histone deacetylases are distinguished by a highly complex substrate and site specificity
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DOI：
10.1021/bi982702v
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发表时间：
1999-05-25
期刊：
影响因子：
2.9
通讯作者：
Loidl, P
中科院分区：
文献类型：
--
作者：
Kölle, D;Brosch, G;Loidl, P
参与组蛋白乙酰化的酶已被鉴定为重要的转录调节因子。玉米胚含有三个组蛋白去乙酰化酶家族：RPD 3型去乙酰化酶（HD 1-B），HD 2家族的核仁磷蛋白，以及与RPD 3和HD 2无关的第三种形式（HD 1-A）。在这里，我们首先报告的核心组蛋白，乙酰化组蛋白H4亚种，和乙酰化H4-赖氨酸残基的脱乙酰酶的特异性。HD 1-A、HD 1-B和HD2使所有四种核心组蛋白脱乙酰化，尽管具有不同的特异性。然而，实验组蛋白从不同的来源（超乙酰化的MELC和鸡组蛋白）使用抗体特异性单独乙酰化的H4-赖氨酸位点表明，酶识别高度不同的乙酰化模式。只有RPD 3-型脱乙酰酶HD 1-B能够将纯化的细胞质组蛋白乙酰转移酶B与纯的非乙酰化H4亚种孵育后引入的特异性H4双乙酰化模式（位置12和5）脱乙酰化。HD 1-A和HD2以磷酸化形式存在。去磷酸化具有显著但相反的效果;而HD2在去磷酸化后失去酶活性，HD 1-A被激活，改变了对乙酰化H4亚种的特异性。这些数据表明，不同类型的脱乙酰酶与核小体上不同的和高度特异性的乙酰化模式相互作用。
Enzymes involved in histone acetylation have been identified as important transcriptional regulators. Maize embryos contain three histone deacetylase families: RPD3-type deacetylases (HD1-B), nucleolar phosphoproteins of the HD2 family, and a third form unrelated to RPD3 and HD2 (HD1-A). Here we first report on the specificity of deacetylases for core histones, acetylated histone H4 subspecies, and acetylated H4-lysine residues. HD1-A, HD1-B, and HD2 deacetylate all four core histones, although with different specificity. However, experiments with histones from different sources (hyperacetylated MELC and chicken histones) using antibodies specific for individually acetylated H4-lysine sites indicate that the enzymes recognize highly distinct acetylation patterns. Only RPD3-type deacetylase HD1-B is able to deacetylate the specific H4 di-acetylation pattern (position 12 and 5) introduced by the purified cytoplasmic histone acetyltransferase B after incubation with pure nonacetylated H4 subspecies. HD1-A and HD2 exist as phosphorylated forms. Dephosphorylation has dramatic, but opposite effects; whereas HD2 loses enzymatic activity upon dephosphorylation, HD1-A is activated with a change of specificity against acetylated H4 subspecies. The data suggest that different types of deacetylases interact with different and highly specific acetylation patterns on nucleosomes.