Essential protein (PubMed:20675571, PubMed:25452667). Negatively regulates the response to iron deficiency and thus contributes to iron homeostasis (PubMed:20675571, PubMed:25794933). Exhibits E3 ubiquitin-protein ligase activity in vitro (PubMed:24253678, PubMed:25452667). Plays a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation (PubMed:25452667, PubMed:27359166). Facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron (PubMed:25452667). Protein modification; protein ubiquitination. Interacts with the PYEL proteins bHLH115, bHLH104 and ILR3 in the nucleus (PubMed:20675571, PubMed:25452667). Binds zinc and iron ions (PubMed:24253678, PubMed:25452667). Expressed in cotyledons of seedlings, young leaves, developing and mature embryos, and other reproductive tissues including floral vasculature, funiculus, septum, and gynoecium valves. By iron deficiency, specifically in the root vasculature (e.g. pericycle) (PubMed:20675571, PubMed:25452667). Destabilized upon iron-binding (PubMed:25452667). Embryonic lethal (PubMed:20675571, PubMed:25452667). Increased tolerance to iron deprivation (PubMed:20675571, PubMed:25794933, PubMed:27359166). Over-accumulation of iron ions in phloems, rosette leaves, flowers and seeds. In normal conditions, at the late reproductive stage, aborted siliques and abnormal necrotic lesions in cauline leaves (PubMed:25794933). Increased root elongation, rhizosphere acidification, and iron reductase activity under iron deficiency (PubMed:25452667, PubMed:27359166).