Central factor in signaling pathways regulated by ethylene (ET), and involved in various processes including development, plant defense, senescence, nucleotide sugar flux, and tropisms. Necessary for ethylene-mediated gene regulation, and for the induction of some genes by ozone. Acts downstream of ET receptors, and upstream of ethylene regulated transcription factors. Required for cytokinin-mediated processes. Seems to be implicated in cross-talk between ET, jasmonate and other pathways. Probably not involved in iron uptake. Has a short half-life and undergoes rapid proteasome-mediated turnover in the absence of ethylene. Required for ethylene-induced EIN3 stabilization via proteasomal degradation of EBF1/EBF2 proteins. Regulates the leaf senescence induced by methyl jasmonate, ethylene and abscisic acid (Ref.17, PubMed:15010611). Required during salt stress to confer resistance.; Trafficking signal inducing ethylene response. The nuclear localization is both necessary and sufficient to activate EIN3-mediated transcription and ethylene responses. Necessary and sufficient for 3'-UTR-mediated translational repression of EBF1 and EBF2 mRNAs. Ethylene induces EIN2-CEND to associate with 3' UTRs in cytoplasmic foci and target EBF1/2 mRNAs to cytoplasmic processing-body (P-body). MPK6 regulates the cleavage and nuclear translocation of EIN2-CEND under methyl jasmonate treatment. Required for EIN3 accumulation.