| 15295098 |
Kepinski S, Leyser O: Auxin-induced SCFTIR1-Aux/IAA interaction involves stable modification of the SCFTIR1 complex. Proc Natl Acad Sci U S A. 2004 Aug 17;101(33):12381-6. Epub 2004 Aug 4.
The plant hormone auxin can regulate gene expression by destabilizing members of the Aux/IAA family of transcriptional repressors. Auxin-induced Aux/IAA degradation requires the protein-ubiquitin ligase SCF (TIR1), with auxin acting to enhance the interaction between the Aux/IAAs and SCF (TIR1). SKP1, Cullin, and an F-box-containing protein (SCF)-mediated degradation is an important component of many eukaryotic signaling pathways. In all known cases to date, the interaction between the targets and their cognate SCFs is regulated by signal-induced modification of the target. The mechanism by which auxin promotes the interaction between SCF (TIR1) and Aux/IAAs is not understood, but current hypotheses propose auxin-induced phosphorylation, hydroxylation, or proline isomerization of the Aux/IAAs. We found no evidence to support these hypotheses or indeed that auxin induces any stable modification of Aux/IAAs to increase their affinity for SCF (TIR1). Instead, we present data suggesting that auxin promotes the SCF (TIR1)-Aux/IAA interaction by affecting the SCF component, TIR1, or proteins tightly associated with it. |
1(0,0,0,1) |