NF-κB1 p105/p50 Antibody (YA6065),MedChemexpress,HY-P86373

NF-κB1 p105/p50 is a pleiotropic transcription factor present in nearly all cell types, serving as the endpoint of diverse signal transduction cascades initiated by stimuli linked to biological processes such as inflammation, immunity, differentiation, cell growth, tumorigenesis, and apoptosis. NF-κB forms homo- or heterodimeric complexes with Rel-like domain-containing proteins (e.g., RELA/p65, RELB, NFKB1/p105, NFKB1/p50, REL, NFKB2/p52), with the p65-p50 heterodimer being the most abundant. These dimers bind κB sites in target gene DNA, exhibiting distinct affinity and specificity for different κB sequences, functioning as transcriptional activators or repressors. NF-κB activity is regulated by post-translational modifications, subcellular localization, and interactions with cofactors/corepressors. Inactive NF-κB complexes are sequestered in the cytoplasm by I-κB inhibitors. Upon activation, I-κB is phosphorylated by IKKs and degraded, releasing NF-κB for nuclear translocation. The p65-p50 and RelB-p50 heterodimers are transcriptional activators, while the p50-p50 homodimer acts as a repressor unless bound to BCL3. NFKB1 has dual roles: p105 retains NF-κB proteins in the cytoplasm, while cotranslational processing generates p50. Proteasome-mediated processing ensures independent functions of p50 and p105, though post-translational processing also occurs. p50 binds the κB consensus sequence 5'-GGRNNYYCC-3' in enhancers of immune/acute-phase response genes and regulates apoptosis. NFKB1/p105-MAP3K8 complexes inhibit MAPK signaling; active MAP3K8 is released upon p105 degradation. p105 is the precursor of the p50 subunit, which forms the transcriptionally active p65-p50 complex with RELA/p65. Isoform 3 (p98) transactivates NF-κB-regulated genes, unlike p84 or p105. p105 may also inhibit p50's transactivation by cytoplasmic sequestration.

NFKB1; Nuclear factor NF-kappa-B p105 subunit; DNA-binding factor KBF1; EBP-1; Nuclear factor of kappa light polypeptide gene enhancer in B-cells 1