The plant hormone auxin, in particular indole-3-acetic acid (IAA), is a key regulator of virtually every aspect of plant growth and development. Auxin regulates transcription by rapidly modulating levels of Aux/IAA proteins throughout development. Recent studies demonstrate that auxin perception occurs through a novel mechanism. Auxin binds to TIR1, the F-box subunit of the ubiquitin ligase complex SCF(TIR1), and stabilizes the interaction between TIR1 and Aux/IAA substrates. This interaction results in Aux/IAA ubiquitination and subsequent degradation. Regulation of the Aux/IAA protein family by TIR1 and TIR1-like auxin receptors (AFBs) links auxin action to transcriptional regulation and provides a model by which the vast array of auxin influences on development may be understood. Moreover, auxin receptor function is the first example of small-molecule regulation of an SCF ubiquitin ligase and may have important implications for studies of regulated protein degradation in other species, including animals.

中文翻译：

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生长素受体和植物发育：一种新的信号范式。

植物激素生长素，尤其是吲哚-3-乙酸（IAA），实际上是植物生长和发育各个方面的关键调节剂。生长素通过在整个发育过程中快速调节Aux / IAA蛋白的水平来调节转录。最近的研究表明，生长素的感知是通过一种新的机制发生的。生长素与泛素连接酶复合物SCF（TIR1）的F-box亚基TIR1结合，并稳定TIR1与Aux / IAA底物之间的相互作用。这种相互作用导致Aux / IAA泛素化并随后降解。TIR1和类似TIR1的生长素受体（AFB）对Aux / IAA蛋白家族的调控将生长素的作用与转录调控联系起来，并提供了一个模型，通过该模型可以理解生长素对发育的各种影响。此外，