Fig. 1. Mitochondrial respiration is sustained in the absence of extracellular Cys₂.

a Basal oxygen consumption rate of NSCLC cells stimulated with 10 mM glucose and 2mM L-glutamine following culture in the presence or absence of cystine (n = 4 biologically independent samples per condition). b Percentage of basal oxygen consumption linked to the generation of ATP in NSCLC cells fed or starved of cystine (n = 4 biologically independent samples per condition). c Average relative TMRE fluorescence of NSCLC cells cultured with indicated [cystine] or treated with FCCP for 15 min (n = 3 biologically independent samples per condition). d Oligomycin-sensitive oxygen consumption rate of cystine-fed or starved NSCLC cells (n = 4 biologically independent samples per condition). e FCCP-stimulated oxygen consumption rate in in NSCLC cells fed or starved of cystine (n = 4 biologically independent samples per condition). f Average relative MitoTracker Green fluorescence of NSCLC cells cultured in the presence or absence of cystine (n = 3 biologically independent samples per condition). For all experiments, cells were cultured in the indicated [cystine] for 20 h prior to the indicated analysis. Data represent mean values ± s.d. For (a, b, d–f), P values were calculated using a two-tailed unpaired Student’s t-test. For (c), P values were calculated using a one-way ANOVA. All data are representative of at least 3 experimental replicates. For (a–f), source data provided as a Source Data file.