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；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-2 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.