The role of regulated protein degradation in auxin response
- Cite this article as:
- Dharmasiri, S. & Estelle, M. Plant Mol Biol (2002) 49: 401. doi:10.1023/A:1015203013208
Auxin-regulated gene expression is mediated by two families of transcription factors. The ARF proteins bind to a conserved DNA sequence called the AuxRE and activate transcription. The Aux/IAA proteins repress ARF function, presumably by forming dimers with ARF proteins. Recent genetic studies in Arabidopsis indicate that auxin regulates this system by promoting the ubiquitin-mediated degradation of the Aux/IAA proteins, thus permitting ARF function. Mutations in components of SCFTIR1, a ubiquitin protein ligase (E3) result in stabilization of Aux/IAA proteins and decreased auxin response. Further, recent biochemical experiments indicate that the Aux/IAA proteins bind SCFTIR1 in an auxin-dependent manner.