Fig. 7
From: Protein degradation: expanding the toolbox to restrain cancer drug resistance
Protein degradation modulates the tumor microenvironment. IKK can be stabilized by CYLD to facilitate the phosphorylation of IκB, which can be reversed by KEAP1-mediated ubiquitylation on IKK. β-TrCP induces activation of the NF-κB pathway by ubiquitinating IκB, resulting in nucleus translocation of the NF-κB complex. β-TrCP and KEAP1 facilitate NRF2 degradation, while USP17 can deubiquitinate NRF2. KEAP1 can also be regulated by DUB USP15. Under hypoxic conditions, HIF-1α can translocate into the nucleus and facilitate transcription of hypoxic genes. While under normoxia, HIF-1α can be oxidated and further ubiquitinated by VHL for degradation. USP22, USP29, and USP14 can deubiquitylate HIF-1α