Related Experiment Video
Updated: May 12, 2026

Tuning Degradation to Achieve Specific and Efficient Protein Depletion
Published on: July 20, 2019
ARF-Aux/IAA interactions through domain III/IV are not strictly required for auxin-responsive gene expression
Shucai Wang1, Gretchen Hagen, Tom J Guilfoyle
1Current affiliation: Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology; Northeast Normal University; Changchun, PR China.
Abstract:
Auxin response factors (ARFs), together with auxin/indole acetic acid proteins (Aux/IAAs), are transcription factors that play key roles in regulating auxin-responsive transcription in plants. Current models for auxin signaling predict that auxin response is dependent on ARF-Aux/IAA interactions mediated by the related protein-protein interaction domain (i.e., referred to as the CTD) found in the ARF and Aux/IAA C-terminal regions. When auxin concentrations in a cell are low, ARF activators residing on the promoters of auxin response genes are thought to be inactive because of the association with dominant Aux/IAA repressors. When auxin concentrations are elevated, the Aux/IAA repressors are recruited to auxin receptors and degraded via the ubiquitin-proteasome pathway. Destruction of the Aux/IAA repressors allows the ARF activators to function in derepressing/activating auxin response genes. While this auxin signaling pathway is simple and attractive, it is unclear whether auxin-regulated gene expression is solely dependent on ARF-Aux/IAA interactions. Here we show that auxin can affect the expression of auxin response genes in a manner that is independent of the ARF activator CTD.
Related Concept Videos
Cell Signaling in Plants
RNA Polymerase II Accessory Proteins
Conservation of Protein Domains Over Different Proteins
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
Prokaryotic Transcriptional Activators and Repressors
Transcription of prokaryotic...
Combinatorial Gene Control
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
Plant Hormones

