GSK3B and BTRC:CUL1-mediated-degradation of NFE2L2

GSK3B and BTRC:CUL1-mediated-degradation of NFE2L2 In addition to KEAP1:CUL3-mediated degradation in the cytosol, NFE2L2 appears to also be subject to degradation by a BTRC:CUL1 E3 ligase (reviewed in Cuadrado, 2015; Baird and Yamamoto, 2020; Yamamoto et al, 2018). Degradation by the BTRC:CUL1 pathway is mediated by interaction with the NFE2L2 Neh6 domain, and is stimulated by GSK3B-mediated phosphorylation of the Neh6 DSGIS motif. GSK3B-dependent Neh6 phosphorylation is primed by the phosphorylation of a cluster of adjacent serines by unknown kinase(s) (Salazar et al, 2006; Rada et al, 2011; Rada et L, 2012; Rojo et al, 2012; Chen et al, 2017; reviewed in Baird and Yamamoto, 2020). Inhibitory phosphorylation of GSK3B by activated PI3K/AKT signaling relieves BTRC:CUL1-mediated NFE2L2 degradation and provides a biochemical link between activated PI3K signaling and increased NFE2L2 pathway activity (reviewed in Cuadrado, 2015; Baird and Yamamoto, 2020; Yamamoto et al, 2018).