K4, K9 and K18 in human histone H3 are targets for biotinylation by biotinidase
K4, K9 and K18 in human histone H3 are targets for biotinylation by biotinidase
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DOI：
10.1111/j.1742-4658.2005.04839.x
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发表时间：
2005-08-01
期刊：
影响因子：
5.4
通讯作者：
Zempleni, J
中科院分区：
文献类型：
--
作者：
Kobza, K;Camporeale, G;Zempleni, J
组蛋白在翻译后被修饰，例如通过赖氨酸和精氨酸残基的甲基化以及通过丝氨酸残基的磷酸化。这些修饰调节基因表达、DNA 修复、有丝分裂和减数分裂等过程。最近，有证据表明组蛋白也可以通过维生素生物素的共价结合进行修饰。本研究的目的是鉴定组蛋白 H3 中的生物素化位点，并研究组蛋白生物素化、甲基化和磷酸化之间的串扰。基于人组蛋白 H3 序列的合成肽被用作生物素酶生物素化的底物；使用链霉亲和素过氧化物酶探测肽中的生物素。这些研究提供的证据表明组蛋白 H3 中的 K4、K9 和 K18 是生物素化的良好靶点； K14和K23是相对较差的目标。生成针对组蛋白 H3 的抗体，在 K4、K9 或 K18 处进行生物素化。在免疫细胞化学和免疫印迹实验中，这些抗体定位于人胎盘细胞的细胞核，表明组蛋白 H3 中的赖氨酸在体内被生物素化。 R2、R8 和 R17 的二甲基化分别增加了生物素酶对 K4、K9 和 K18 的生物素化； S10 的磷酸化消除了 K9 的生物素化。这些观察结果与组蛋白生物素化和其他已知组蛋白修饰之间的串扰一致。我们推测这种串扰提供了生物素在基因表达和细胞增殖中的已知作用的联系。
Histones are modified post-translationally, e.g. by methylation of lysine and arginine residues, and by phosphorylation of serine residues. These modifications regulate processes such as gene expression, DNA repair, and mitosis and meiosis. Recently, evidence has been provided that histones are also modified by covalent binding of the vitamin biotin. The aims of this study were to identify biotinylation sites in histone H3, and to investigate the crosstalk among histone biotinylation, methylation and phosphorylation. Synthetic peptides based on the sequence of human histone H3 were used as substrates for enzymatic biotinylation by biotinidase; biotin in peptides was probed using streptavidin peroxidase. These studies provided evidence that K4, K9 and K18 in histone H3 are good targets for biotinylation; K14 and K23 are relatively poor targets. Antibodies were generated to histone H3, biotinylated either at K4, K9 or K18. These antibodies localized to nuclei in human placental cells in immunocytochemistry and immunoblotting experiments, suggesting that lysines in histone H3 are biotinylated in vivo. Dimethylation of R2, R8 and R17 increased biotinylation of K4, K9 and K18, respectively, by biotinidase; phosphorylation of S10 abolished biotinylation of K9. These observations are consistent with crosstalk between biotinylation of histones and other known modifications of histones. We speculate that this crosstalk provides a link to known roles for biotin in gene expression and cell proliferation.