Auxin signaling pathway

The auxin signaling pathway is a fundamental regulatory network in plants that governs growth, development, and responses to environmental stimuli. It is primarily mediated by the hormone indole-3-acetic acid (IAA), which functions as a molecular glue to promote the interaction between the Transport Inhibitor Response 1 (TIR1) or Auxin Signaling F-box (AFB) proteins and the Aux/IAA transcriptional repressors (Dharmasiri et al., 2005, Nature). This interaction facilitates the ubiquitination of Aux/IAA proteins by the SCF-TIR1/AFB E3 ubiquitin ligase complex, leading to their degradation by the 26S proteasome (Tan et al., 2007, Nature). The degradation of these repressors allows Auxin Response Factors (ARFs) to activate the transcription of genes involved in cell elongation, division, and differentiation. While not a natural therapeutic target in humans, this pathway is the primary target for synthetic auxin herbicides like 2,4-D and dicamba, which induce lethal overgrowth in broadleaf plants (Grossmann, 2010, Plant Signaling & Behavior). Additionally, the auxin-inducible degron (AID) system has become a vital tool in biomedical research, allowing scientists to achieve rapid and reversible degradation of specific proteins in mammalian cells to study their function and role in diseases like cancer (Nishimura et al., 2009, Nature Methods).

Other names

IAA signaling pathwayIndole-3-acetic acid signaling pathway

Molecular glue-mediated degradation of Aux/IAA repressor proteins via the SCF-TIR1/AFB E3 ubiquitin ligase complex