Central factor in signaling pathways regulated by ethylene (ET) and involved in various processes including development, plant defense, senescence, nucleotide sugar flux, and tropisms (PubMed:27694846, PubMed:28874528). 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 (PubMed:10381874, PubMed:12953109, PubMed:14973160, PubMed:15010611, PubMed:15272873, PubMed:7770519, PubMed:9351240). Has a short half-life and undergoes rapid proteasome-mediated turnover in the absence of ethylene (PubMed:19196655). Required for ethylene-induced EIN3 stabilization via proteasomal degradation of EBF1/EBF2 proteins (PubMed:20647342). Regulates the leaf senescence induced by methyl jasmonate, ethylene and abscisic acid (Ref.17, PubMed:15010611). Required during salt stress to confer resistance (PubMed:21631530). Trafficking signal inducing ethylene response. The nuclear localization is both necessary and sufficient to activate EIN3-mediated transcription and ethylene responses (PubMed:23070300). Involved in ethylene (ET)-mediated signaling pathways by triggering histone acetylation of H3K14 and H3K23 in an ENAP1-dependent manner, thus influencing the expression of ethylene-responsive genes (PubMed:27694846, PubMed:28874528). 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) (PubMed:26496607, PubMed:26496608). MPK6 regulates the cleavage and nuclear translocation of EIN2-CEND under methyl jasmonate treatment (PubMed:26507893). Required for EIN3 accumulation (PubMed:26507893). Interacts (via NLS) with ETR1 (PubMed:19769567, PubMed:25843012). Interacts (via C-terminus) with EER5 and the COP9 signalosome subunits CSN3, CSN6A and CSN6B (PubMed:18429939). Interacts with ETP1 and ETP2 (PubMed:19196655). Interacts with CTR1 (PubMed:23132950). Interacts with all members of the ethylene receptor family, including ETR1, ETR2, ERS1, ERS2 and EIN4 (PubMed:20591837). Binds to MRF3/ECIP1 (PubMed:21631530). Interacts with several P-body components, such as XRN4/EIN5, PAB2, PAB4 and PAB8 (PubMed:26496607). Binds to ENAP1 in the presence of ethylene; this reaction facilitates its association with histone (PubMed:27694846, PubMed:28874528). Perception of ethylene or methyl jasmonate leads to proteolytic cleavage allowing the C-terminal domain to localize to the nucleus while the N-terminus remains at the endoplasmic reticulum membrane. Apart from nuclear localization, some association with endoplasmic membranes and some speckles are also observed in the cytoplasm. During hypoxia (e.g. submergences), translocates from endoplasmic reticulum (ER) to the nucleus via a ceramides-triggered and CTR1-dependent manner (PubMed:25822663). Localized to the guard cells after methyl jasmonate treatment. Accumuates upon hypoxia (e.g. submergences) (PubMed:25822663). Expression level is enhanced by a chromatin-dependent epigenetic regulatory mechanism involving both EEN and REF6/EIN6 (PubMed:31418686). The N-terminal (1-560) region seems to be regulated by upstream components of the ET signal transduction pathway, and may in turn regulate the C-terminal region. The C-terminal (454-1294) region regulates downstream events of ET and jasmonate signaling pathways, and can confer constitutive responses to ET. The C-terminal (1047-1294) region is necessary and sufficient for interactions with ETP1 and ETP2 (PubMed:19196655). The nuclear localization signal (1262-1269) is required for interaction with ETR1 (PubMed:25843012). Phosphorylated by CTR1 on at least 4 sites. Phosphorylation of Ser-645 and Ser-924 is involved in repressing EIN2 signaling. Loss of phosphorylation results in nuclear localization of the C-terminus of EIN2. Complete ethylene insensitivity (PubMed:10381874). Extreme salt sensitivity during seed germination and plant growth leading to epinastic backward growth of leaf blade and petiole, and small rosette size (PubMed:21631530). Reduced ethylene-induced histone acetylation of H3K14 and H3K23 associated with a lower induction of ethylene-responsive genes (PubMed:27694846, PubMed:28874528). 'Oresara' means 'long living' in Korean. Belongs to the NRAMP (TC 2.A.55) family.