IKKb/IKBKB

Among the catalytic subunits of the IKK complex, IKKβ (IKBKB) is the dominant kinase driving canonical NF-κB activation in response to inflammatory cytokines, Toll-like receptor ligands and stress signals. IKKβ phosphorylates N-terminal serine residues of IκBα and IκBβ, triggering their K48-linked polyubiquitination and proteasomal degradation and releasing NF-κB to induce proinflammatory gene programs. IKKβ also phosphorylates numerous substrates beyond IκB, linking it to insulin signaling, cell survival and tumor promotion. Because sustained IKKβ activity underlies chronic inflammation and inflammation-driven cancer, it is a well-validated drug target. Recombinant IKKβ is widely used for inhibitor screening and NF-κB pathway reconstitution.