Direct ETTIN-auxin interaction controls chromatin state in gynoecium development
Direct ETTIN-auxin interaction controls chromatin state in gynoecium development
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ETTIN-生长素直接相互作用控制雌蕊发育中的染色质状态
DOI：
10.1101/863134
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Kuhn A
中科院分区：
文献类型：
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作者：
Kuhn A
动物中的激素信号通常涉及调节基因表达的直接转录因子-激素相互作用。相比之下，植物激素信号传导最常见的是基于通过转录阻遏物的降解的去阻遏。最近，我们发现了一个非经典的信号机制，植物激素生长素，生长素直接影响活性的非典型生长素反应因子（ARF），ETTIN对靶基因，而不需要蛋白质降解。在这里，我们表明，ETTIN直接结合生长素，导致解离从顶/顶相关家族的辅阻遏蛋白，然后组蛋白乙酰化和诱导基因表达。这种机制让人想起动物激素信号传导，因为它影响靶基因调节的活性，并提供了植物中DNA结合激素受体的第一个例子。虽然生长素通过促进Aux/IAA阻遏物的降解间接影响典型的ARF，但直接的ETTIN-生长素相互作用允许以瞬时可逆的方式在阻遏和去阻遏染色质状态之间切换。
Hormonal signalling in animals often involves direct transcription factor-hormone interactions that modulate gene expression. In contrast, plant hormone signalling is most commonly based on de-repression via the degradation of transcriptional repressors. Recently, we uncovered a non-canonical signalling mechanism for the plant hormone auxin whereby auxin directly affects the activity of the atypical auxin response factor (ARF), ETTIN towards target genes without the requirement for protein degradation. Here we show that ETTIN directly binds auxin, leading to dissociation from co-repressor proteins of the TOPLESS/TOPLESS-RELATED family followed by histone acetylation and induction of gene expression. This mechanism is reminiscent of animal hormone signalling as it affects the activity towards regulation of target genes and provides the first example of a DNA-bound hormone receptor in plants. Whilst auxin affects canonical ARFs indirectly by facilitating degradation of Aux/IAA repressors, direct ETTIN-auxin interactions allow switching between repressive and de-repressive chromatin states in an instantly-reversible manner.