IκBα

Nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha
Crystallographic structure (PDB: 1NFI​) of I?B? (magenta) complexed with a homodimer of the NF-?B heterodimeric protein (p65 - cyan and p50 - green).
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1IKN​, 1NFI​
Identifiers
Symbols	NFKBIA ; IKBA; MAD-3; NFKBI
External IDs	OMIM: 164008 MGI: 104741 HomoloGene: 7863 ChEMBL: 2898 GeneCards: NFKBIA Gene
Gene ontology Molecular function • protein binding • transcription factor binding • nuclear localization sequence binding • enzyme binding • heat shock protein binding • ubiquitin protein ligase binding • protein complex binding • identical protein binding • NF-kappaB binding Cellular component • nucleus • cytoplasm • cytosol • plasma membrane • I-kappaB/NF-kappaB complex Biological process • protein import into nucleus, translocation • stimulatory C-type lectin receptor signaling pathway • toll-like receptor signaling pathway • MyD88-dependent toll-like receptor signaling pathway • MyD88-independent toll-like receptor signaling pathway • apoptotic process • cytoplasmic sequestering of NF-kappaB • negative regulation of macrophage derived foam cell differentiation • positive regulation of cholesterol efflux • negative regulation of lipid storage • viral process • lipopolysaccharide-mediated signaling pathway • negative regulation of NF-kappaB transcription factor activity • positive regulation of cellular protein metabolic process • positive regulation of type I interferon production • response to muramyl dipeptide • toll-like receptor 2 signaling pathway • toll-like receptor 3 signaling pathway • toll-like receptor 4 signaling pathway • toll-like receptor 5 signaling pathway • toll-like receptor 9 signaling pathway • toll-like receptor 10 signaling pathway • TRIF-dependent toll-like receptor signaling pathway • response to muscle stretch • Fc-epsilon receptor signaling pathway • toll-like receptor TLR1:TLR2 signaling pathway • toll-like receptor TLR6:TLR2 signaling pathway • regulation of cell proliferation • regulation of NF-kappaB import into nucleus • cytoplasmic sequestering of transcription factor • negative regulation of apoptotic process • response to exogenous dsRNA • negative regulation of DNA binding • innate immune response • negative regulation of myeloid cell differentiation • negative regulation of Notch signaling pathway • positive regulation of transcription from RNA polymerase II promoter • neurotrophin TRK receptor signaling pathway • T cell receptor signaling pathway • positive regulation of NF-kappaB transcription factor activity • cellular response to cold • nucleotide-binding oligomerization domain containing 1 signaling pathway • nucleotide-binding oligomerization domain containing 2 signaling pathway Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	4792	18035
Ensembl	ENSG00000100906	ENSMUSG00000021025
UniProt	P25963	Q9Z1E3
RefSeq (mRNA)	NM_020529	NM_010907
RefSeq (protein)	NP_065390	NP_035037
Location (UCSC)	Chr 14: 35.4 – 35.4 Mb	Chr 12: 55.49 – 55.49 Mb
PubMed search

IκBα (nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha) is one member of a family of cellular proteins that function to inhibit the NF-κB transcription factor. IκBα inhibits NF-κB by masking the nuclear localization signals (NLS) of NF-κB proteins and keeping them sequestered in an inactive state in the cytoplasm.^[1] In addition, IκBα blocks the ability of NF-κB transcription factors to bind to DNA, which is required for NF-κB's proper functioning.^[2]

Disease linkage

The gene encoding the IκBα protein is mutated in some Hodgkin's lymphoma cells; such mutations inactivate the IκBα protein, thus causing NF-κB to be chronically active in the lymphoma tumor cells and this activity contributes to the malignant state of these tumor cells.^[3]

Interactions

IκBα has been shown to interact with:

References

Further reading

External links

• OMIM entries on Ectodermal Dysplasia, Anhidrotic, with T-cell Immunodeficiency
• NFKBIA protein, human at the US National Library of Medicine Medical Subject Headings (MeSH)
• NF-kappaB inhibitor alpha at the US National Library of Medicine Medical Subject Headings (MeSH)

PDB gallery 1ikn: IKAPPABALPHA/NF-KAPPAB COMPLEX  1nfi: I-KAPPA-B-ALPHA/NF-KAPPA-B COMPLEX