IKBKB Gene - Structure, Function, and Clinical Significance

IKBKB encodes IKK-beta (inhibitor of nuclear factor kappa-B kinase subunit beta), a serine/threonine kinase that forms the core of the IKK complex. Upon activation by upstream signals, IKK-beta phosphorylates inhibitors of NF-κB (IκBs), leading to their ubiquitin-dependent degradation and subsequent nuclear translocation of NF-κB transcription factors. This pathway regulates expression of genes involved in inflammation, immunity, cell survival, and proliferation. Mutations in IKBKB cause severe combined immunodeficiency (SCID) and are implicated in various cancers.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• NF-kappa B signaling pathway (KEGG: hsa04064)

• Toll-like receptor signaling pathway (KEGG: hsa04620)

• TNF signaling pathway (KEGG: hsa04668)

• RIG-I-like receptor signaling pathway (KEGG: hsa04622)

• B cell receptor signaling pathway (KEGG: hsa04662)

• T cell receptor signaling pathway (KEGG: hsa04660)

IKK-beta (UniProt O14920) is a 756-amino-acid serine/threonine kinase containing an N-terminal kinase domain, a ubiquitin-like domain (ULD), and a C-terminal NEMO-binding domain (NBD). It forms a heterodimer with IKK-alpha and interacts with the regulatory subunit NEMO (IKK-gamma) to form the IKK complex. Activation occurs via phosphorylation at Ser177 and Ser181 in the activation loop. IKK-beta is the primary kinase responsible for IκB phosphorylation in the canonical NF-κB pathway. Its activity is tightly regulated; dysregulation contributes to inflammatory diseases, immunodeficiency, and cancer.