Unser 10. Leibniz Plant Biochemistry Symposium am 7. und 8. Mai war ein großer Erfolg. Thematisch ging es in diesem Jahr um neue Methoden und Forschungsansätze der Naturstoffchemie. Die exzellenten Vorträge über Wirkstoffe…
Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Antolín-Llovera, M.; Ried, M. K.; Parniske, M.;Cleavage of the SYMBIOSIS RECEPTOR-LIKE KINASE Ectodomain Promotes Complex Formation with Nod Factor Receptor 5Curr. Biol.24422-427(2014)DOI: 10.1016/j.cub.2013.12.053
Plants form root symbioses with fungi and bacteria to improve their nutrient supply. SYMBIOSIS RECEPTOR-LIKE KINASE (SYMRK) is required for phosphate-acquiring arbuscular mycorrhiza, as well as for the nitrogen-fixing root nodule symbiosis of legumes [1] and actinorhizal plants [2, 3], but its precise function was completely unclear. Here we show that the extracytoplasmic region of SYMRK, which comprises three leucine-rich repeats (LRRs) and a malectin-like domain (MLD) related to a carbohydrate-binding protein from Xenopus laevis [4], is cleaved to release the MLD in the absence of symbiotic stimulation. A conserved sequence motif—GDPC—that connects the MLD to the LRRs is required for MLD release. We discovered that Nod factor receptor 5 (NFR5) [5, 6, 7, 8] forms a complex with the SYMRK version that remains after MLD release (SYMRK-ΔMLD). SYMRK-ΔMLD outcompeted full-length SYMRK for NFR5 interaction, indicating that the MLD negatively interferes with complex formation. SYMRK-ΔMLD is present at lower amounts than MLD, suggesting rapid degradation after MLD release. A deletion of the entire extracytoplasmic region increased protein abundance, suggesting that the LRR region promotes degradation. Curiously, this deletion led to excessive infection thread formation, highlighting the importance of fine-tuned regulation of SYMRK by its ectodomain.