Fig. 3: Adenylate depletion promotes metabolic flux through the de novo serine synthesis pathway.
From: Purine nucleotide depletion prompts cell migration by stimulating the serine synthesis pathway
a Schematic of carbon flow from13C6-glucose into glycolytic and serine synthesis intermediates. PHGDH inhibitors: BI-4924, NCT-503. b Normalized peak areas of 3-phosphoserine (M + 3) and serine (M + 3) from HeLa cells treated with either veh (DMSO) or MTX (2 µM, 15 h), followed by adenine supplementation (50 µM, 1 h), and labelled with 13C6-glucose in the last hour. c As in b, but from HeLa cells treated with MTX (2 µM, 15 h), in the presence or absence of BI-4924 (15 µM), or NCT503 (10 µM), and labelled for the last 3 h with 13C6-glucose. d As in b, but from ΔPHGDH HEK293E cells reconstituted or not with PHGDH cDNA, treated with LTX (4 µM, 8 h), and labelled with 13C6-glucose (1 h). e As in b, but from HeLa cells treated with MTX (2 µM) in the presence or absence of GAPDH inhibitor heptelidic acid (75 µM, 15 h), and labelled with 13C6-glucose (3 h). f Extracellular acidification rate (ECAR) of HeLa cells treated with veh (DMSO) or MTX (2 µM, 15 h). g Normalized peak areas of lactate from HeLa cells treated with MTX (2 µM) (Left panel) or from wild-type or (ΔGART) HeLa cells grown without nucleotides for 24 h. h Oxygen consumption rate (OCR) of HeLa cells treated with MTX (2 µM, 15 h). i Immunoblots of wild-type and knockout PKM2 (ΔPKM2) MEFs, treated with veh (DMSO) or MTX (2 µM, 8 h). j As in b, but from wild-type and ΔPKM2 MEFs treated as in i and labelled with 13C6-glucose (3 h). k As in b, but from HeLa cells that were pretreated with TEPP-46 (100 µM, 1 h) prior to treatment with MTX (2 µM, 8 h), and labelled with 13C6-glucose (3 h). b–h, j, k Data are presented as the mean ± s.d from n = 3 (d, e, g, j), n = 4 (b, c, k), or n = 6 (f, h) of biologically independent samples. b–e, j, k One-way ANOVA, Turkey’s post-hoc test, multiple comparison, g Unpaired t-test, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Data are representative of n = 2 (d, f, g, h) or n = 3 (b, c, e, i–k) independent experiments. Source data and exact p-values are provided as a Source Data file.
