Extended Data Fig. 8: PFKFB4–SRC-3 stabilizes ATF4 transcription factor to promote purine synthesis.
From: Metabolic enzyme PFKFB4 activates transcriptional coactivator SRC-3 to drive breast cancer
a, Chromatin localization peaks of SRC-3 and ATF4 on Tkt, Xdh and Ampd1 genes in mouse liver. b, ATF4-binding peaks are conserved on three SRC-3 target purine biosynthetic genes in both mouse and human genomes. c, Chromatin immunoprecipitation (ChIP) of ATF4, total SRC-3 and pSRC-3-Ser857 from MDA-MB-231 cells treated with 5 mM or 25 mM glucose compared to an IgG isotype control. qPCR was performed to determine amount of promoter enrichment. d, ChIP–qPCR was performed from MDA-MB-231 cells cultured in 25 mM glucose expressing SRC-3 shRNA, PFKFB4 shRNA or control shRNA. n = 3 biological cell samples. *P < 0.01, **P < 0.0001, ***P < 0.00005, ****P < 0.000001, one-way ANOVA with Tukey’s multiple comparisons test compared to 5 mM glucose groups (c) and compared to NT shRNA group (d). e, ChIP of ATF4, total SRC-3 (BD Biosciences antibody), and pSRC-3-Ser857 from MDA-MB-231 cells on the AMPD1 promoter treated with non-targeting siRNA or siRNA against ATF4, and cultured in presence of 25 mM glucose compared to an IgG isotype control. qPCR was performed to determine the amount of promoter enrichment. n = 3 biological cell samples. ***P < 0.001, ****P < 0.000001, one-way ANOVA with Tukey’s multiple comparisons test. f, mRNA expression of TKT, XDH, AMPD1 and SRC-3 in MDA-MB-231 cells expressing siRNA targeting control or ATF4 siRNA. n = 3 biological cell samples. two-way ANOVA with Sidak’s multiple comparisons test. See Source Data for exact P values. Data are mean ± s.d.
