Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, Austin, Texas 78712, USA.
Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.
Nat Commun. 2016 Oct 3;7:13018. doi: 10.1038/ncomms13018.
Ethylene gas is essential for many developmental processes and stress responses in plants. EIN2 plays a key role in ethylene signalling but its function remains enigmatic. Here, we show that ethylene specifically elevates acetylation of histone H3K14 and the non-canonical acetylation of H3K23 in etiolated seedlings. The up-regulation of these two histone marks positively correlates with ethylene-regulated transcription activation, and the elevation requires EIN2. Both EIN2 and EIN3 interact with a SANT domain protein named EIN2 nuclear associated protein 1 (ENAP1), overexpression of which results in elevation of histone acetylation and enhanced ethylene-inducible gene expression in an EIN2-dependent manner. On the basis of these findings we propose a model where, in the presence of ethylene, the EIN2 C terminus contributes to downstream signalling via the elevation of acetylation at H3K14 and H3K23. ENAP1 may potentially mediate ethylene-induced histone acetylation via its interactions with EIN2 C terminus.
乙烯气体是植物许多发育过程和应激反应所必需的。EIN2 在乙烯信号转导中起着关键作用，但它的功能仍然是个谜。在这里，我们表明乙烯特异性地提高了黄化幼苗中组蛋白 H3K14 的乙酰化和 H3K23 的非典型乙酰化。这两个组蛋白标记的上调与乙烯调节的转录激活呈正相关，并且这种升高需要 EIN2。EIN2 和 EIN3 都与一个名为 EIN2 核相关蛋白 1（ENAP1）的 SANT 结构域蛋白相互作用，过表达 ENAP1 会导致组蛋白乙酰化水平升高，并以 EIN2 依赖的方式增强乙烯诱导的基因表达。基于这些发现，我们提出了一个模型，即在乙烯存在的情况下，EIN2 的 C 端通过提高 H3K14 和 H3K23 的乙酰化水平，有助于下游信号转导。ENAP1 可能通过与 EIN2 C 端的相互作用来介导乙烯诱导的组蛋白乙酰化。
