Acetylation in the globular core of histone H3 on lysine-56 promotes chromatin disassembly during transcriptional activation
Acetylation in the globular core of histone H3 on lysine-56 promotes chromatin disassembly during transcriptional activation
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DOI：
10.1073/pnas.0800057105
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发表时间：
2008-07
期刊：
影响因子：
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通讯作者：
Stephanie K. Williams;David Truong;J. Tyler
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文献类型：
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作者：
Stephanie K. Williams;David Truong;J. Tyler
启动子染色质解体是一种广泛应用的调节真核生物转录诱导的机制。延迟从酵母PHO 5启动子去除组蛋白H3/H4也导致延迟去除组蛋白H2 A/H2 B，表明H2 A/H2 B的组装和拆卸的恒定平衡，而H3/H4拆卸是高度调节的步骤。为了了解H3/H4解体是如何调节的，我们观察到组蛋白H3乙酰化赖氨酸-56（K56 ac）在启动子染色质解体过程中的水平急剧增加。事实上，启动子染色质解体是由Rtt 109和Asf 1依赖的乙酰化H3 K56驱动的。相反，在转录抑制过程中启动子染色质重组伴随着组蛋白H3乙酰化赖氨酸-56水平的降低，并且阻止K56乙酰化的突变增加了转录抑制的速率。因此，H3 K56乙酰化在转录激活期间驱动染色质朝向分解状态，而H3 K56乙酰化的丧失驱动染色质朝向组装状态。
Promoter chromatin disassembly is a widely used mechanism to regulate eukaryotic transcriptional induction. Delaying histone H3/H4 removal from the yeast PHO5 promoter also leads to delayed removal of histones H2A/H2B, suggesting a constant equilibrium of assembly and disassembly of H2A/H2B, whereas H3/H4 disassembly is the highly regulated step. Toward understanding how H3/H4 disassembly is regulated, we observe a drastic increase in the levels of histone H3 acetylated on lysine-56 (K56ac) during promoter chromatin disassembly. Indeed, promoter chromatin disassembly is driven by Rtt109 and Asf1-dependent acetylation of H3 K56. Conversely, promoter chromatin reassembly during transcriptional repression is accompanied by decreased levels of histone H3 acetylated on lysine-56, and a mutation that prevents K56 acetylation increases the rate of transcriptional repression. As such, H3 K56 acetylation drives chromatin toward the disassembled state during transcriptional activation, whereas loss of H3 K56 acetylation drives the chromatin toward the assembled state.