Inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ) (IKKβ)

Inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ) is the primary catalytic subunit of the IκB kinase (IKK) complex and a master regulator of the canonical NF-κB signaling pathway [1, 3, 9]. It plays a central role in the cellular response to pro-inflammatory stimuli, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 (IL-1), by phosphorylating inhibitory IκB proteins [4, 5]. This phosphorylation triggers the ubiquitination and subsequent proteasomal degradation of IκB, allowing the NF-κB transcription factor complex to translocate into the nucleus and activate genes involved in immunity, inflammation, and cell survival [5, 11]. Dysregulation of the IKKβ/NF-κB axis is strongly associated with the pathogenesis of chronic inflammatory diseases, autoimmune disorders, and various cancers, where it contributes to tumor progression and therapeutic resistance [7, 10]. While IKKβ is a highly attractive therapeutic target, the development of small-molecule inhibitors has been complicated by significant safety concerns, including systemic toxicity and potential immunosuppression due to its broad physiological roles [2, 10].

Other names

IKK2IKBKBIKK-betaNFKBIKBI-kappa-B kinase 2Nuclear factor kappa-B kinase subunit betaNuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)

IKKβ inhibitors primarily act by binding to the ATP-binding site or allosteric sites of the kinase, preventing the phosphorylation of IκB proteins. This inhibition blocks the degradation of IκB, thereby keeping the NF-κB transcription factor complex sequestered in the cytoplasm and preventing the transcription of pro-inflammatory and pro-survival genes [4, 5, 10]. Some inhibitors, such as Bardoxolone methyl, act through covalent modification of specific cysteine residues within the kinase domain [5].