Fig. 3: Loss of MGME1 leads to depletion of dNTPs and mtDNA replication-dependent innate immune signalling.
From: Ribonucleotide incorporation into mitochondrial DNA drives inflammation
a, ISG expression in immortalized MEFs after small interfering RNA (siRNA)-mediated downregulation of mtDNA-replication-related enzymes for 72 h. Fold changes in ISG expression are shown (relative to cells transfected with scrambled siRNA (ctrl)). n = 3 biologically independent experiments. b, ISG expression in Mgme1+/+ and Mgme1−/− immortalized MEFs (relative to Mgme1+/+) treated with the indicated endoribonuclease-prepared siRNA (esiRNA) for 72 h. n = 3 biologically independent experiments. c, Sequence coverage after next-generation sequencing of kidney mtDNA from Mgme1−/− and control (Mgme1+/+) mice. Mitochondrial genome position (x axis) versus sequence coverage divided by the total coverage for each sample. For each genotype, two samples derived from different mice were analysed. The approximate locations of the origins of light-strand (OL) and heavy-strand (OH) replication are indicated by dotted lines with arrows. d, dNTP levels in cell lysates of Mgme1+/+ and Mgme1−/− immortalized MEFs as measured by LC–MS. n = 6 independent cultures. Data are representative of three biologically independent experiments. Normalization was performed to input protein values. e,f, ISG expression in Mgme1+/+ and Mgme1−/− immortalized MEFs treated with siRNA against Samhd1 (e) and Slc25a33 (f) as indicated for 72 h. n = 3 biologically independent experiments. Knockdown controls for a are shown in Extended Data Fig. 6a. The complete nucleotide landscape relevant to d is shown in Extended Data Fig. 6d. P values were calculated using two-way ANOVA with the Tukey’s multiple-comparison test (a,b,e,f) or two-tailed unpaired Student t-tests (d). Data are mean ± s.d.
