Phosphorylation of Histone H2A at Serine 95: A Plant-Specific Mark Involved in Flowering Time Regulation and H2A.Z Deposition
Phosphorylation of Histone H2A at Serine 95: A Plant-Specific Mark Involved in Flowering Time Regulation and H2A.Z Deposition
复制标题
组蛋白 H2A 丝氨酸 95 处的磷酸化：参与开花时间调节和 H2A.Z 沉积的植物特异性标记
DOI：
10.1105/tpc.17.00266
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发表时间：
2017-09-01
期刊：
影响因子：
11.6
通讯作者：
Ding, Yong
中科院分区：
文献类型：
--
作者：
Su, Yanhua;Wang, Shiliang;Ding, Yong
组蛋白H3的磷酸化影响转录、染色质凝聚和染色体分离。然而，组蛋白H2A磷酸化的作用尚不清楚。在这里，我们发现拟南芥mut9p样激酶（MLK4）在丝氨酸95上磷酸化组蛋白H2A，这是组蛋白核心区域的植物特异性修饰。MLK4突变在长日照条件下导致开花延迟，但在短日照条件下无显著表型。MLK4与CIRCADIAN CLOCK ASSOCIATED1 （CCA1）相互作用，从而允许MLK4与GIGANTEA （GI）启动子结合。CCA1与YAF9a相互作用，YAF9a是Swi2/ snf2相关atp酶（SWR1）和NuA4复合物的共同亚基，负责整合组蛋白变体H2A。Z分别进入染色质和组蛋白H4乙酰化酶活性。重要的是，MLK4功能的丧失通过降低H2A丝氨酸95的磷酸化导致开花延迟，同时减弱H2A的积累。Z和H4在GI的乙酰化，从而降低GI的表达。总之，我们的研究结果揭示了H2A丝氨酸95的磷酸化是如何促进开花时间的，并表明MLK4调节的H2A丝氨酸95的磷酸化是调节开花时间所必需的，并且参与了组蛋白变体H2A的沉积。拟南芥中Z和H4乙酰化。
Phosphorylation of histone H3 affects transcription, chromatin condensation, and chromosome segregation. However, the role of phosphorylation of histone H2A remains unclear. Here, we found that Arabidopsis thaliana MUT9P-LIKE-KINASE (MLK4) phosphorylates histone H2A on serine 95, a plant-specific modification in the histone core domain. Mutations in MLK4 caused late flowering under long-day conditions but no notable phenotype under short days. MLK4 interacts with CIRCADIAN CLOCK ASSOCIATED1 (CCA1), which allows MLK4 to bind to the GIGANTEA (GI) promoter. CCA1 interacts with YAF9a, a co-subunit of the Swi2/Snf2-related ATPase (SWR1) and NuA4 complexes, which are responsible for incorporating the histone variant H2A. Z into chromatin and histone H4 acetylase activity, respectively. Importantly, loss of MLK4 function led to delayed flowering by decreasing phosphorylation of H2A serine 95, along with attenuated accumulation of H2A. Z and the acetylation of H4 at GI, thus reducing GI expression. Together, our results provide insight into how phosphorylation of H2A serine 95 promotes flowering time and suggest that phosphorylation of H2A serine 95 modulated by MLK4 is required for the regulation of flowering time and is involved in deposition of the histone variant H2A. Z and H4 acetylation in Arabidopsis.