Department of Biochemistry, University of Missouri, 117 Schweitzer Hall, Columbia, MO 65211, USA.
Plant Sci. 2012 Jul;190:82-8. doi: 10.1016/j.plantsci.2012.04.003. Epub 2012 Apr 13.
Auxin Response Factors (ARFs) and Indole Acetic Acid (IAA) proteins contain a similar carboxyl-terminal domain (domain III/IV) that facilitates interactions among these transcription factors as well as other proteins. The specificity of these interactions is controversial, and the mechanisms involved in these interactions have not been investigated. Here, we review some of the controversies about the specificities and requirements for ARF and IAA interactions and discuss some of the technical problems that might contribute to differences reported for these interactions. We make some preliminary conclusions that ARF activator-IAA, ARF activator-ARF activator, and ARF repressor-ARF repressor interactions are favored over ARF repressor-IAA and ARF repressor-ARF activator interactions, and we suggest that IAA-IAA interactions are largely indiscriminant. Based upon the predicted secondary structure of domain III/IV, we introduce a model for how ARF and IAA proteins might interact with one another through a ubiquitin-like β-grasp fold.
生长素响应因子 (ARFs) 和吲哚乙酸 (IAA) 蛋白含有相似的羧基末端结构域 (结构域 III/IV)，这有助于这些转录因子以及其他蛋白质之间的相互作用。这些相互作用的特异性存在争议，并且尚未研究这些相互作用涉及的机制。在这里，我们回顾了关于 ARF 和 IAA 相互作用特异性和要求的一些争议，并讨论了可能导致对这些相互作用的报道存在差异的一些技术问题。我们得出一些初步结论，即 ARF 激活剂-IAA、ARF 激活剂-ARF 激活剂和 ARF 抑制剂-ARF 抑制剂相互作用比 ARF 抑制剂-IAA 和 ARF 抑制剂-ARF 激活剂相互作用更有利，并且我们认为 IAA-IAA 相互作用在很大程度上是无差别的。根据结构域 III/IV 的预测二级结构，我们提出了一个模型，说明 ARF 和 IAA 蛋白如何通过泛素样β-grasp 折叠相互作用。
