title: Non-proteolytic protein ubiquitination is crucial for iron deficiency signaling.
abstract: Ubiquitination generally targets proteins for recognition and degradation via the 26S proteasome. Activated ubiquitin (E1) is transferred to an ubiquitin conjugase (UBC, E2) which associates with a ubiquitin ligase (E3), and multiple ubiquitin molecules are attached via linkage of Lys 48. By contrast, Lys 63-linked ubiquitin chains modify proteins in a non-proteolytic manner. We recently reported that UBC13, the only known ubiquitin conjugase capable of catalyzing Lys 63-linked polyubiqitination, is responsive to the iron (Fe) regime at the post-transcriptional level and may play a crucial role for the morphological alterations triggered by Fe deficiency in cucumber and Arabidopsis roots. It is assumed that UBC13 participates, most likely via the non-proteolytic polyubiquitination of proteins, in the signal transduction cascade associated with the acclimation of plants to the prevailing availability of Fe. In this Addendum, we present a possible scenario that occurs downstream of UBC13, which ultimately leads to Fe deficiency-specific changes in post-embryonic development of Arabidopsis roots.
authors.affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schmidt
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D000090463:Iron Deficiencies; D008954:Models, Biological; D025941:Protein Interaction Mapping; D059748:Proteolysis; D015398:Signal Transduction; D044763:Ubiquitin-Conjugating Enzymes; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D007501:Iron; C513138:UBC13B protein, Arabidopsis; D044763:Ubiquitin-Conjugating Enzymes