KDM2

KDM2 (lysine demethylase 2) proteins, primarily KDM2A and KDM2B, are JmjC-domain histone demethylases that recognize unmethylated CpG islands through a conserved CXXC DNA-binding domain and regulate chromatin organization and transcriptional repression by targeting histone H3K36 methylation states^[1]. Mechanistically, KDM2 proteins function at CpG island-associated promoters and integrate epigenetic control with transcriptional programs that influence cell identity, proliferation, and developmental gene regulation^[1]. KDM2A additionally regulates signaling-associated transcriptional networks through interactions with non-histone substrates, whereas KDM2B is closely linked to Polycomb-associated gene silencing pathways, highlighting both shared and specialized regulatory functions within the family^[1]. Disease relevance is supported by evidence connecting KDM2 dysregulation to developmental abnormalities, tumor progression, stem-cell-associated phenotypes, and altered cellular differentiation programs^[2][3]. Compared with the canonical full-length isoforms, alternative short isoforms of KDM2A and KDM2B lack the N-terminal demethylase domain but retain DNA-binding and protein-interaction capacities, demonstrating that transcriptional regulation can occur independently of catalytic demethylase activity^[1][2]. In experimental models, KDM2A-SF and KDM2B-SF repress canonical Wnt target genes, including AXIN2 and CCND1, and negatively regulate Wnt-responsive transcription through promoter binding and interaction with TCF7L1^[2]. Therefore, the distinction between long and short KDM2 isoforms provides an important framework for mechanistic studies of epigenetic regulation and pathway-specific gene control in disease-relevant systems^[1][2].