Functional analysis of molecular interactions in synthetic auxin response circuits

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 113; no. 40; pp. 11354 - 11359
• Main Authors: Pierre-Jerome, Edith, Moss, Britney L., Lanctot, Amy, Hageman, Amber, Nemhauser, Jennifer L.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 04.10.2016
• Subjects: Acetic acid; Arabidopsis - drug effects; Arabidopsis - genetics; Biological Sciences; Deoxyribonucleic acid; DNA; Flowers & plants; Gene Expression Regulation, Plant - drug effects; Gene Regulatory Networks; Indoleacetic Acids - pharmacology; Models, Biological; Mutation - genetics; Plants, Genetically Modified; Promoter Regions, Genetic - genetics; Protein Multimerization; Proteins; Recombinant Fusion Proteins - metabolism; Response Elements - genetics; Transcription, Genetic - drug effects; Transgenes; Yeast; Yeasts; synthetic circuits; transcription; ARF; auxin signaling; PB1
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1604379113

Auxin-regulated transcription pivots on the interaction between the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) repressor proteins and the AUXIN RESPONSE FACTOR (ARF) transcription factors. Recent structural analyses of ARFs and Aux/IAAs have raised questions about the functional complexes driving auxin transcriptional responses. To parse the nature and significance of ARF–DNA and ARF–Aux/IAA interactions, we analyzed structure-guided variants of synthetic auxin response circuits in the budding yeast Saccharomyces cerevisiae. Our analysis revealed that promoter architecture could specify ARF activity and that ARF19 required dimerization at two distinct domains for full transcriptional activation. In addition, monomeric Aux/IAAs were able to repress ARF activity in both yeast and plants. This systematic, quantitative structure-function analysis identified a minimal complex—comprising a single Aux/IAA repressing a pair of dimerized ARFs—sufficient for auxin-induced transcription.