Figure 2.

NRF2 regulates serine biosynthesis. (a) Nuclear NRF2 protein expression correlates with ¹³C-serine M3 labelling at 24 hours. Nuclear NRF2 protein expression data is found in Supplementary Fig. 7. (b) Cell lines with high NRF2 activity have significantly higher ¹³C serine M3 labelling at 6 and 24 hours. Cell lines were grouped according to the NRF2 score into “high” (>1.4) and “low” (<1.4). (c) NRF2 high cell lines have significantly higher ¹³C glycine M2 labelling at 24 hours. (b,c) p-values were calculated using an unpaired, two-tailed student’s t-test. (d) mRNA expression in A549 cells expressing scramble shRNA (SCR) or NRF2 shRNA #1. Decreased NQO1 expression confirmed that NRF2 activity was reduced upon knockdown. Results are the average of 3 technical replicates. (e) Western blot of serine pathway enzyme expression in lysates from A549 cells expressing scramble (SCR), or NRF2 shRNAs #1 or #2. (f) Cell lines were grown in the presence of U-¹³C-glucose for the indicated time points, the metabolites extracted and the fractional ¹³C-labelling on serine analysed by LC/MS. Results are the average of 3 biological replicates.