Fig. 6: The mRNA nuclear export function of PGC-1α is essential to its cellular function and mitochondrial homeostasis.

a–d Cell lines were induced with doxycycline for 72 h and cultured in glucose prior to switching or not in galactose media for the last 24 h. OXPHOS western blots of complex I, II, III & IV protein levels of Ctrl-RNAi and PGC-1α RNAi (a) or of PGC-1α WT and PGC-1α ΔRS (b) cell lines. OXPHOS western blots shown in panels (a) and (b) were performed in three independent experiments and changes in COX2 levels quantified and normalised against the total mitochondrial protein level (the sum of all 5 complexes) (Mean ± SEM; two-way ANOVA with Sidak’s correction for multiple comparisons; NS: not significant, **p = 0.0013 (c), **p = 0.0024 (d); N = 3). e–j Functional mitochondrial assays. Sham, Ctrl-RNAi, PGC-1α-RNAi, WT-res and ΔRS-res cell lines were induced with doxycycline for 6 days and cultured in glucose prior to galactose switch for the last 24 h. e–g Mitochondrial respiratory chain complex II (e), IV (f) and I (g) enzymatic activity were performed in three independent experiments (Mean ± SEM; one-way ANOVA with Turkey’s correction for multiple comparisons; NS: not significant *p < 0.05, **p < 0.01, ***p < 0.001; N = 3). h Genomic mitochondrial MT-ND1 DNA levels were performed in five independent experiments and analysed by qPCR following normalisation to the nuclear B2M gene and to 100% of Sham cell line (Mean ± SEM; one-way ANOVA with Tukey’s correction for multiple comparisons; NS: not significant, *p = 0.0334, **p = 0.0026; N = 5). i, j MTT cell proliferation assays were performed in glucose or after a 24 h galactose induction in five independent experiments (Mean ± SEM; one-way ANOVA with Tukey’s correction for multiple comparisons; NS: not significant, **p < 0.02, ***p < 0.001; N = 5). For panels c–j, source data are provided with details of statistical tests and exact p-values as a Source data file.