IκB kinase – Nuclear factor-kappa B signaling pathway (IKK-NF-κB)

The IκB kinase (IKK) – Nuclear factor-kappa B (NF-κB) signaling pathway is a fundamental regulator of the cellular response to stress, cytokines, and pathogens (Oeckinghaus & Ghosh, 2009, PMID: 19851317). The pathway is centered on the IKK complex, which consists of catalytic subunits (IKKα and IKKβ) and a regulatory subunit (IKKγ/NEMO) (UniProt: O14920, P51817). Upon activation by stimuli such as TNF-α or Toll-like receptor ligands, the IKK complex phosphorylates IκB proteins, marking them for proteasomal degradation. This release allows NF-κB transcription factors to enter the nucleus and drive the expression of genes critical for inflammation, immune cell activation, and the inhibition of apoptosis (Nature Reviews Molecular Cell Biology, 2017). In many cancers and chronic inflammatory diseases, this pathway is constitutively active, promoting tumor survival and persistent tissue damage (PubMed: 16007092). Consequently, components of this pathway, particularly the IKK complex and the proteasome, are major targets for therapeutic intervention in oncology and rheumatology (DrugBank: DB00188). However, because NF-κB is essential for normal immune function, targeting this pathway requires careful management of potential immunosuppressive side effects and systemic toxicity.

Other names

IKK/NF-kappaB pathwayNF-kappaB signalingI-kappa-B kinase complexNF-kappaB pathway

Inhibition of the IKK complex prevents the phosphorylation and subsequent degradation of IκB proteins, thereby sequestering NF-κB in the cytoplasm and preventing its transcriptional activity. Proteasome inhibitors also block this pathway by preventing the degradation of phosphorylated IκB.