Phosphorylated C-terminal serines 866, 870 and 872 in NFKB2 creates binding site for beta-TRCP (beta-transducin repeat-containing protein), the receptor subunit of a SCF-type of E3 ubiquitin ligase, SCF beta-TRCP (Liang et al. 2006). The SKP1-CUL1-F-box (SCF) ubiquitin E3 ligase superfamily is the largest family of cullin-RING ligases, with interchangeable F-box proteins orchestrating the trafficking proteins for ubiquitination and degradation (Weathington & Mallampalli 2013). Beta-TRCP is an F-box protein that contains two domains, an F-box motif that binds SKP1 and allows assembly into SKP1-CUL1 complexes and a second protein-protein interaction domain that interacts with phosphorylated serines in NFKB2 (Bai et al. 1996, Skowyra et al. 1997, Patton et al. 1998).