Fig. 1: Generation of tools to manipulate cellular NADH/NAD+ and NADPH/NADP+.

a Enzymatic reactions catalyzed by STH and LbNOX. b Western blots for the expression of inducible Tet-on Flag-tagged EcSTH in HeLa cells induced by Dox (0.1 µg/mL) for different times. c The ratios of cellular NADH/NAD⁺ and NADPH/NADP⁺ in HeLa cells expressing Tet-on Flag-tagged EcSTH cultured with Dox (0.1 µg/mL) for 12 h (n = 3 biologically independent samples). From left to right: **P = 1.08e-05, **P = 1.10e-05, **P = 0.0015, **P = 6.88e-05. d Schematic for the fusion of EcSTH and LbNOX. e Western blots for the expression of inducible Tet-on fusions of EcSTH with LbNOX in HeLa cells induced by Dox (0.1 µg/mL) for 12 h. f The ratios of cellular NADH/NAD⁺ and NADPH/NADP⁺ in HeLa cells expressing Tet-on fusion of EcSTH with LbNOX cultured with Dox (0.1 µg/mL) for 12 h (n = 3 biologically independent samples). From left to right: **P = 2.03e-07, **P = 2.64e-05. g Secretory lactate/pyruvate (Lac/Pyr, n = 3 biologically independent samples) and β-hydroxybutyrate/acetoacetate (β-HB/AcAc, n = 4 biologically independent samples) of HeLa cells expressing inducible Tet-on EGFP, EcSTH or EcSTH-LbNOX cultured with Dox (0.1 µg/mL) for 12 h. From left to right: **P = 6.50e-05, **P = 7.62e-05, **P = 8.37e-06, **P = 2.29e-05. All experimental data were verified in at least three independent experiments. Error bars represent mean ± SD. **P < 0.01; Two-tailed Student’s t-tests. Source data are provided as a Source Data file.