Fig 2: Levels of COQ biosynthetic proteins A–D Representative Western blot and quantitation of Western blot bands of COQ7 (A), ADCK3 (B), COQ5 (C) and COQ6 (D), and VDAC1 as a loading control in the kidneys of 3-month-old mice. *P < 0.05; **P < 0.01; ***P < 0.001; Coq9Q95X and Coq9R239X mice versus Coq9+/+ mice. ##P < 0.01; ###P < 0.001; Coq9Q95X versus Coq9R239X mice. One-way ANOVA with a Tukey's post hoc test. E–H Representative Western blot and quantitation of Western blot bands of COQ7 (E), ADCK3 (F), COQ5 (G) and COQ6 (H), and VDAC1 as a loading control in skeletal muscle of 3-month-old mice. **P < 0.01; ***P < 0.001; Coq9Q95X and Coq9R239X mice versus Coq9+/+ mice. #P < 0.05; ##P < 0.01; Coq9Q95X versus Coq9R239X mice. Data information: All values are presented as mean ± SD. One-way ANOVA with a Tukey's post hoc test. Numbers above columns indicate P-values of the one-way ANOVA test. Coq9+/+ mice n = 4; Coq9Q95X and Coq9R239X mice n = 5.Source data are available online for this figure.

Fig 3: Levels of CoQ and the biosynthetic proteins COQ7, COQ5, COQ6 and COQ8A. (A) CoQ9 levels in liver homogenates of young adult, middle-age and old Coq9Q95X and Coq9+/+ male mice. (B–E) Representative western blot of COQ7 (B), COQ5 (C), COQ6 (D) and COQ8A (E) and their quantitative analysis in the liver of young adult, middle-age and old Coq9Q95X and Coq9+/+ male mice. *P < 0.05; **P < 0.01; *** P < 0.001; Coq9Q95X versus Coq9+/+ littermates mice. The mitochondrial Tom20 was used as loading control. The specific band for each target protein is identified with an arrow, and only these bands were used in the quantification (the lower bands in COQ5 and COQ6). Note that the anti-COQ6 antibody recognizes two bands that may correspond to the full-length and mature (mitochondrial import) forms of COQ6 or, alternatively, to two different COQ6 isoforms38,39. Data information: (A–E) Data are expressed as mean ± SD. Statistical analyses were performed on Coq9+/+ male mice versus Coq9Q95X male mice by Multiple Student’s t-test one per row. (A) Coq9+/+ mice, n = 6; Coq9Q95X mice, n = 6, at each age (B–E) Coq9+/+ mice, n = 5; Coq9Q95X mice, n = 5, at each age WB images from (A–E) were cropped from two different parts of the same gel at the same exposure.