The role of regulated protein degradation in auxin response.
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 SCF(TIR1), 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 SCF(TIR1) in an auxin-dependent manner.
Dharmasiri
Sunethra
S
Institute for Cellular and Molecular Biology, Section of Molecular Cell and Developmental Biology, University of Texas at Austin, USA.
Estelle
Mark
M
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism / Q000494:pharmacology*; D008954:Models, Biological; D009097:Multienzyme Complexes / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism
D007210:Indoleacetic Acids; D009097:Multienzyme Complexes; D010940:Plant Proteins; D014157:Transcription Factors; D025801:Ubiquitin; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex