AI Article Synopsis

  • Auxin, a plant hormone, regulates the expression of thousands of genes through AUXIN RESPONSE transcription FACTORs (ARFs), which bind to specific DNA sequences called AuxRE motifs.
  • Research revealed that ARF1 can form higher-affinity bonds to DNA with an additional hydrogen bond, enhancing its binding potential significantly.
  • The study also found that different ARF subfamilies interact variably with DNA, which helps explain the diverse functions of auxin-responsive elements in plant gene regulation.

Article Abstract

The hormone auxin controls many aspects of the plant life cycle by regulating the expression of thousands of genes. The transcriptional output of the nuclear auxin signaling pathway is determined by the activity of AUXIN RESPONSE transcription FACTORs (ARFs), through their binding to -regulatory elements in auxin-responsive genes. Crystal structures, in vitro, and heterologous studies have fueled a model in which ARF dimers bind with high affinity to distinctly spaced repeats of canonical AuxRE motifs. However, the relevance of this "caliper" model, and the mechanisms underlying the binding affinities in vivo, have remained elusive. Here we biochemically and functionally interrogate modes of ARF-DNA interaction. We show that a single additional hydrogen bond in ARF1 confers high-affinity binding to individual DNA sites. We demonstrate the importance of AuxRE cooperativity within repeats in the and promoters in vivo. Meta-analysis of transcriptomes further reveals strong genome-wide association of auxin response with both inverted (IR) and direct (DR) AuxRE repeats, which we experimentally validated. The association of these elements with auxin-induced up-regulation (DR and IR) or down-regulation (IR) was correlated with differential binding affinities of A-class and B-class ARFs, respectively, suggesting a mechanistic basis for the distinct activity of these repeats. Our results support the relevance of high-affinity binding of ARF transcription factors to uniquely spaced DNA elements in vivo, and suggest that differential binding affinities of ARF subfamilies underlie diversity in element function.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7533888PMC
http://dx.doi.org/10.1073/pnas.2009554117DOI Listing

Publication Analysis

Top Keywords

binding affinities
12
dna elements
8
arf transcription
8
auxin response
8
transcription factors
8
high-affinity binding
8
differential binding
8
binding
7
architecture dna
4
elements
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!