May act as a substrate-specific adapter of an E3 ubiquitin-protein ligase complex (CUL3-RBX1-BTB) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (By similarity). Key positive regulator of the SA-dependent signaling pathway that negatively regulates JA-dependent signaling pathway. Mediates the binding of TGA factors to the as-1 motif found in the pathogenesis-related PR-1 gene, leading to the transcriptional regulation of the gene defense. Controls the onset of systemic acquired resistance (SAR). Upon SAR induction, a biphasic change in cellular reduction potential occurs, resulting in reduction of the cytoplasmic oligomeric form to a monomeric form that accumulates in the nucleus and activates gene expression. Phosphorylated form is target of proteasome degradation. Protein modification; protein ubiquitination. Oligomer in an uninduced state; disulfide-linked. Forms activated monomer upon SAR induction. Interacts with TGA1, TGA3, TGA4, TGA5, TGA6, TGA7 and with reduced forms of TGA1 and TGA4. Interacts with NIMIN-1, NIMIN-2 and NIMIN-3. Accumulation in nucleus after induction by salicylic acid (SA) treatment or after pathogen infection. By salicylic acid (SA), benzol(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH) and 2,6-dichloroisonicotinic acid (INA). The BTB/POZ domain mediates the interaction with some component of ubiquitin ligase complexes. Phosphorylated at Ser-11 and Ser-15 in the nucleus; facilitates its recruitment to a cullin3-based ubiquitin ligase leading to polyubiquitination and subsequent CUL3/CSN-mediated degradation. Ubiquitinated. The Cys-82-SH group reacts with Cys-216-SH of the other subunit to form an intermolecular disulfide. This disulfide might subsequently be reduced upon SAR induction. S-nitrosylation at Cys-156 facilitates its oligomerization.