| Function | NF-kappa-B is a pleiotropic transcription factor present in almost all cell types and is the endpoint of a series of signal transduction events that are initiated by a vast array of stimuli related to many biological processes such as inflammation, immunity, differentiation, cell growth, tumorigenesis and apoptosis. NF-kappa-B is a homo- or heterodimeric complex formed by the Rel-like domain-containing proteins RELA/p65, RELB, NFKB1/p105, NFKB1/p50, REL and NFKB2/p52 and the heterodimeric p65-p50 complex appears to be most abundant one. The dimers bind at kappa-B sites in the DNA of their target genes and the individual dimers have distinct preferences for different kappa-B sites that they can bind with distinguishable affinity and specificity. Different dimer combinations act as transcriptional activators or repressors, respectively. NF-kappa-B is controlled by various mechanisms of post-translational modification and subcellular compartmentalization as well as by interactions with other cofactors or corepressors. NF-kappa-B complexes are held in the cytoplasm in an inactive state complexed with members of the NF-kappa-B inhibitor (I-kappa-B) family. In a conventional activation pathway, I-kappa-B is phosphorylated by I-kappa-B kinases (IKKs) in response to different activators, subsequently degraded thus liberating the active NF-kappa-B complex which translocates to the nucleus. NF-kappa-B heterodimeric p65-p50 and RelB-p50 complexes are transcriptional activators. The NF-kappa-B p50-p50 homodimer is a transcriptional repressor, but can act as a transcriptional activator when associated with BCL3. NFKB1 appears to have dual functions such as cytoplasmic retention of attached NF-kappa-B proteins by p105 and generation of p50 by a cotranslational processing. The proteasome-mediated process ensures the production of both p50 and p105 and preserves their independent function, although processing of NFKB1/p105 also appears to occur post-translationally. p50 binds to the kappa-B consensus sequence 5'-GGRNNYYCC-3', located in the enhancer region of genes involved in immune response and acute phase reactions. In a complex with MAP3K8, NFKB1/p105 represses MAP3K8-induced MAPK signaling.active MAP3K8 is released by proteasome-dependent degradation of NFKB1/p105. Nuclear factor NF-kappa-B p105 subunit: P105 is the precursor of the active p50 subunit (Nuclear factor NF-kappa-B p50 subunit) of the nuclear factor NF-kappa-B. Acts as a cytoplasmic retention of attached NF-kappa-B proteins by p105. Nuclear factor NF-kappa-B p50 subunit: Constitutes the active form, which associates with RELA/p65 to form the NF-kappa-B p65-p50 complex to form a transcription factor. Together with RELA/p65, binds to the kappa-B consensus sequence 5'-GGRNNYYCC-3', located in the enhancer region of genes involved in immune response and acute phase reactions. |
| Protein Name | Nuclear Factor Nf-Kappa-B P105 SubunitDna-Binding Factor Kbf1Ebp-1Nuclear Factor Of Kappa Light Polypeptide Gene Enhancer In B-Cells 1 Cleaved Into - Nuclear Factor Nf-Kappa-B P50 Subunit |
| Database Links | Reactome: R-HSA-1169091Reactome: R-HSA-1810476Reactome: R-HSA-193692Reactome: R-HSA-202424Reactome: R-HSA-209560Reactome: R-HSA-2559582Reactome: R-HSA-2871837Reactome: R-HSA-3134963Reactome: R-HSA-3214841Reactome: R-HSA-381340Reactome: R-HSA-445989Reactome: R-HSA-448706Reactome: R-HSA-5603029Reactome: R-HSA-5607764Reactome: R-HSA-5621575Reactome: R-HSA-5660668Reactome: R-HSA-5684264Reactome: R-HSA-6798695Reactome: R-HSA-844456Reactome: R-HSA-8853884Reactome: R-HSA-9020702Reactome: R-HSA-933542Reactome: R-HSA-9609690Reactome: R-HSA-9660826Reactome: R-HSA-9692916Reactome: R-HSA-9818749 |
| Cellular Localisation | Nuclear Factor Nf-Kappa-B P105 Subunit: CytoplasmNuclear Factor Nf-Kappa-B P50 Subunit: NucleusCytoplasmAssociation With Nfkbia Inhibitor (I-Kappa-B)Promotes Its Retention In The Cytoplasm In An Inactive FormTranslocates Into The Nucleus Following Nfkbia Degradation |
| Alternative Protein Names | Nuclear Factor Nf-Kappa-B P105 Subunit proteinDna-Binding Factor Kbf1 proteinEbp-1 proteinNuclear Factor Of Kappa Light Polypeptide Gene Enhancer In B-Cells 1 Cleaved Into - Nuclear Factor Nf-Kappa-B P50 Subunit proteinNFKB1 protein |
Information sourced from Uniprot.org
