Skp1-Cullin 1-F-box protein Beta-transducin repeat-containing protein complex (SCF^beta-TrCP)

The Skp1-Cullin 1-F-box protein Beta-transducin repeat-containing protein (SCF^beta-TrCP) complex is a multi-subunit E3 ubiquitin ligase that plays a pivotal role in the canonical NF-kappaB signaling pathway (Maniatis, 1999). It specifically recognizes and ubiquitinates IkappaBalpha after it has been phosphorylated by the IKK complex at Ser32 and Ser36 (UniProt P63151). This ubiquitination marks IkappaBalpha for subsequent degradation by the 26S proteasome, which is the critical step allowing the NF-kappaB transcription factor to translocate into the nucleus and activate genes involved in inflammation, immunity, and cell survival (Kanarek & Ben-Neriah, 2012). Beyond IkappaBalpha, the complex regulates other key proteins such as beta-catenin and various cell cycle regulators, making it a central node in cellular homeostasis. In many cancers and chronic inflammatory conditions, the SCF^beta-TrCP complex is associated with the constitutive activation of NF-kappaB, contributing to disease progression and resistance to apoptosis. Therapeutic strategies targeting this complex include the use of NEDD8-activating enzyme inhibitors like Pevonedistat (MLN4924), which prevent the activation of the Cullin-1 subunit, and the development of small molecules that disrupt the interaction between beta-TrCP and its substrates (Soucy et al., 2009). However, because the complex targets multiple substrates, pharmacological intervention carries risks of off-target effects and systemic toxicity.

Other names

SCF(BTRC)SCF(FBXW1)Beta-TrCP E3 ubiquitin ligase complexE3RS(IkappaB)FBXW11-containing SCF complexSkp1-Cullin 1-F-box protein complex

Inhibition of Cullin-1 neddylation by targeting NEDD8-activating enzyme (NAE), thereby preventing the assembly and activity of the SCF^beta-TrCP complex and stabilizing IkappaBalpha (Soucy et al., 2009).