2007/01/13 by Kate Dreher, Judy Callis · 2 citations
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Ubiquitin and proteasome pathways #Plant Molecular Biology Research #Plant responses to water stress #Biology #Ubiquitin #Proteolysis #Proteasome #Cell biology #Hormone #Auxin #Protein degradation #Jasmonate #Deubiquitinating enzyme #Abscisic acid #Biotic stress #Ubiquitin ligase #Biochemistry #Arabidopsis #Abiotic stress #Gene #Mutant #Enzyme
paper · pdf · doi:10.1093/aob/mcl255
openalex publication_date 2007/01/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
BACKGROUND: The covalent attachment of ubiquitin to a substrate protein changes its fate. Notably, proteins typically tagged with a lysine48-linked polyubiquitin chain become substrates for degradation by the 26S proteasome. In recent years many experiments have been performed to characterize the proteins involved in the ubiquitylation process and to identify their substrates, in order to understand better the mechanisms that link specific protein degradation events to regulation of plant growth and development. SCOPE: This review focuses on the role that ubiquitin plays in hormone synthesis, hormonal signalling cascades and plant defence mechanisms. Several examples are given of how targeted degradation of proteins affects downstream transcriptional regulation of hormone-responsive genes in the auxin, gibberellin, abscisic acid, ethylene and jasmonate signalling pathways. Additional experiments suggest that ubiquitin-mediated proteolysis may also act upstream of the hormonal signalling cascades by regulating hormone biosynthesis, transport and perception. Moreover, several experiments demonstrate that hormonal cross-talk can occur at the level of proteolysis. The more recently established role of the ubiquitin/proteasome system (UPS) in defence against biotic threats is also reviewed. CONCLUSIONS: The UPS has been implicated in the regulation of almost every developmental process in plants, from embryogenesis to floral organ production probably through its central role in many hormone pathways. More recent evidence provides molecular mechanisms for hormonal cross-talk and links the UPS system to biotic defence responses.