ABI5-binding proteins (AFPs) alter transcription of ABA-induced genes via a variety of interactions with chromatin modifiers
ABI5-binding proteins (AFPs) alter transcription of ABA-induced genes via a variety of interactions with chromatin modifiers
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DOI：
10.1007/s11103-016-0569-1
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发表时间：
2017-03-01
影响因子：
5.1
通讯作者：
Finkelstein, Ruth R.
中科院分区：
文献类型：
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作者：
Lynch, Tim J.;Erickson, B. Joy;Finkelstein, Ruth R.
ABI5/ABF结合蛋白（AFPs）的过表达通过多种机制抑制ABA反应，包括与组蛋白去乙酰化酶和协同抑制因子toppless的相互作用，导致种子对ABA产生极端抗性。一些ABI5/ABF结合蛋白（AFPs）抑制ABA应答，导致转基因拟南芥过表达系对ABA产生极端抗性，但其作用机制尚不清楚。与相关的新互作物JAZ （NINJA）蛋白类似，表明AFPs与协同抑制因子toppless相互作用，抑制aba调控的基因表达。本研究表明，抑制ABA反应的AFPs在异源系统中具有内在的抑制活性，而不依赖于与toppless相互作用的结构域。该结构域在转基因植物中也不是抑制ABA应答所必需的，但确实有助于增强ABA抗性。在酵母双杂交和双分子荧光实验中观察到一些AFPs和组蛋白去乙酰化酶亚基之间的其他相互作用，这与afp介导的基因表达抑制的更直接机制一致。曲古霉素A对组蛋白去乙酰化酶活性的化学抑制抑制了AFP对一小部分abi5调节基因的影响。综上所述，这些结果表明AFPs参与了多种调节ABA反应的机制，包括topless依赖性和非依赖性染色质修饰。
Overexpression of ABI5/ABF binding proteins (AFPs) results in extreme ABA resistance of seeds via multiple mechanisms repressing ABA response, including interactions with histone deacetylases and the co-repressor TOPLESS.Several ABI5/ABF binding proteins (AFPs) inhibit ABA response, resulting in extreme ABA resistance in transgenic Arabidopsis overexpression lines, but their mechanism of action has remained obscure. By analogy to the related Novel Interactor of JAZ (NINJA) protein, it was suggested that the AFPs interact with the co-repressor TOPLESS to inhibit ABA-regulated gene expression. This study shows that the AFPs that inhibit ABA response have intrinsic repressor activity in a heterologous system, which does not depend on the domain involved in the interaction with TOPLESS. This domain is also not essential for repressing ABA response in transgenic plants, but does contribute to stronger ABA resistance. Additional interactions between some AFPs and histone deacetylase subunits were observed in yeast two-hybrid and bimolecular fluorescence assays, consistent with a more direct mechanism of AFP-mediated repression of gene expression. Chemical inhibition of histone deacetylase activity by trichostatin A suppressed AFP effects on a small fraction of the ABI5-regulated genes tested. Collectively, these results suggest that the AFPs participate in multiple mechanisms modulating ABA response, including both TOPLESS-dependent and -independent chromatin modification.