Transcription factor involved in the activation of hypoxic gene expression and in ethylene response. Partially redundant with RAP2-2. Acts as a downstream regulator in the ethylene signaling pathway. Ethylene-responsive transcription factor RAP2-12, N-terminally processed: The N-terminal cysteine residue of can be oxidized by PCO1 or PCO2, thus preparing the protein for N-end rule pathway-mediated proteasomal degradation. Interacts with ACBP1 and ACBP2. Localizes to the plasma membrane under aerobic conditions, but accumulates in the nucleus upon hypoxia. A number of isoforms are produced. According to EST sequences. Highly expressed in seedlings, leaves, flowers, siliques and germinating seeds. Up-regulated by hypoxia but not by ethylene. The N-terminus (1-13) is important for the regulation of the oxygen-dependent activation of the transcription factor activity, an internal region (123-177) is required for the interactions with ACPB1 and ACPB2, while the C-terminus (343-358) is required for positive regulation of gene transcription. The N-terminus qualifies RAP2-12 as candidate substrate of the N-end rule pathway for protein destabilization. The oxygen-dependent oxidation of Cys-2 prevents hypoxic gene expression via the destabilization of RAP2-12 in air. When the oxygen concentration decreases, Cys oxidation is prevented and an active RAP2.12 accumulates in the nucleus. Belongs to the AP2/ERF transcription factor family. ERF subfamily.