BACH2 Rabbit Polyclonal Antibody

BACH2 (BTB and CNC homolog 2) is a lymphoid-specific transcription factor belonging to the Cap'n'Collar (CNC) basic leucine zipper (bZIP) family, and it plays a key regulatory role in B cell development, T cell differentiation, and immune homeostasis. Structurally, it contains an N-terminal BTB/POZ domain of approximately 100 amino acids (which mediates dimerization and recruits transcriptional corepressors and class II histone deacetylases) and a C-terminal bZIP domain (responsible for DNA binding and dimerization). BACH2 exists as an obligate homodimer, and can also form heterodimers with small MAF proteins (MAFF, MAFG, MAFK) through its bZIP domain, binding to MARE elements to regulate target genes. Functionally, BACH2 acts as a transcriptional repressor, suppressing the expression of genes associated with effector T cell differentiation, maintaining the suppressive function of Treg cells, and regulating B cell class switch recombination and somatic hypermutation. The nucleocytoplasmic shuttling of BACH2 is regulated by PI3K-AKT signaling-mediated phosphorylation and SUMOylation. Genetic evidence indicates that BACH2 haploinsufficiency can cause monogenic BACH2-related immunodeficiency and autoimmunity syndrome, characterized by reduced FOXP3 expression in Treg cells and increased expression of gut-homing receptors on CD4⁺ T cells, with clinical manifestations of colitis combined with B cell immunodeficiency. Polymorphisms at the BACH2 locus are also associated with susceptibility to a variety of autoimmune diseases, including rheumatoid arthritis, Crohn's disease, multiple sclerosis, type 1 diabetes, and asthma.