Site specificity analysis of Piccolo NuA4-mediated acetylation for different histone complexes.
Site specificity analysis of Piccolo NuA4-mediated acetylation for different histone complexes.
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DOI：
10.1042/bj20150654
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发表时间：
2015-12-01
期刊：
影响因子：
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通讯作者：
Andrews AJ
中科院分区：
文献类型：
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作者：
Kuo YM;Henry RA;Tan S;Côté J;Andrews AJ
我们对多亚基赖氨酸乙酰转移酶（KAT）复合物对组蛋白底物的位点特异性了解有限，特别是在核小体组装过程中形成的不同复合物方面。组蛋白复合物可能是决定KATs乙酰化特异性的主要因素。在本研究中，我们采用一种基于无标记定量质谱的方法来确定Piccolo NuA4对（H3/H4）2四聚体、四聚体结合DNA（四体）和核小体核心颗粒（NCP）催化乙酰化的位点特异性。我们的研究结果表明，Piccolo NuA4可以乙酰化这三种组蛋白复合物上的多个赖氨酸残基，其中NCP是最有利的，（H3/H4）2四聚体是第二有利的，四体是Piccolo NuA4乙酰化的最不利底物。虽然Piccolo NuA4优先乙酰化组蛋白H4 (H4K12)，但该酶的位点特异性随着不同的组蛋白复合物底物而改变。我们的研究结果表明，在核小体组装完成之前，H3K14的特异性几乎等于H4K12， dna -组蛋白相互作用抑制了Piccolo NuA4的乙酰化能力。这些数据表明，H2A/H2B二聚体可能在增加Piccolo NuA4对NCP的乙酰化特异性中起关键作用。这表明组蛋白复合物的形成可以改变Piccolo NuA4的乙酰化偏好。这些发现为通过调节染色质动力学来调节Piccolo NuA4特异性，进而操纵基因表达提供了有价值的见解。
We have a limited understanding of the site specificity of multisubunit lysine acetyltransferase (KAT) complexes for histone-based substrates, especially in regards to the different complexes formed during nucleosome assembly. Histone complexes could be a major factor in determining the acetylation specificity of KATs. In the present study, we utilized a label-free quantitative mass spectrometry-based method to determine the site specificity of acetylation catalyzed by Piccolo NuA4 on (H3/H4)2 tetramer, tetramer bound DNA (tetrasome), and nucleosome core particle (NCP). Our results show that Piccolo NuA4 can acetylate multiple lysine residues on these three histone complexes, of which NCP is the most favorable, (H3/H4)2 tetramer is the second, and tetrasome is the least favorable substrate for Piccolo NuA4 acetylation. Although Piccolo NuA4 preferentially acetylates histone H4 (H4K12), the site specificity of the enzyme is altered with different histone complex substrates. Our results show that before nucleosome assembly is complete, H3K14 specificity is almost equal to that of H4K12 and DNA-histone interactions suppress the acetylation ability of Piccolo NuA4. These data suggest that the H2A/H2B dimer could play a critical role in the increase of acetylation specificity of Piccolo NuA4 for NCP. This demonstrates that histone complex formation can alter the acetylation preference of Piccolo NuA4. Such findings provide valuable insight into regulating Piccolo NuA4 specificity by modulating chromatin dynamics, and in turn manipulating gene expression.