NFKB1 Protein, Human (His)

NFKB1 protein serves as a pivotal component of the pleiotropic transcription factor NF-kappa-B, found ubiquitously across various cell types. This transcription factor acts as a central mediator in signal transduction pathways associated with diverse biological processes, including inflammation, immunity, differentiation, cell growth, tumorigenesis, and apoptosis. NFKB1 participates in homo- or heterodimeric complexes, with the p65-p50 heterodimer being the most prevalent. These dimers selectively bind to kappa-B sites in target gene DNA, exhibiting distinct preferences and affinities. NF-kappa-B regulation involves intricate post-translational modifications, subcellular compartmentalization, and interactions with cofactors or corepressors. In an inactive state, NF-kappa-B complexes associate with NF-kappa-B inhibitor (I-kappa-B) family members in the cytoplasm. Activation ensues through phosphorylation and degradation of I-kappa-B, liberating active NF-kappa-B complexes for nuclear translocation. NFKB1 exhibits dual functions, contributing to cytoplasmic retention of NF-kappa-B proteins and generating the active p50 subunit through cotranslational processing. This processing, mediated by the proteasome, ensures the independent functionality of p50 and p105. The p50 subunit binds to kappa-B consensus sequences in the enhancer regions of genes involved in immune response and acute phase reactions. Additionally, NFKB1, in association with MAP3K8, represses MAP3K8-induced MAPK signaling, with active MAP3K8 released through proteasome-dependent degradation of NFKB1/p105.