Fig. 4: Opposite effects of ROMO1 upregulation and ablation on mitochondrial Ca²⁺ uptake.

a Heat map of the activity-based protein profiling ratios of TG/WT at MCU C96 and C190 in different mouse tissues. n = 3-4 independent biological replicates from 6-8 young mice (3-month-old) for each tissue (2 M 4 F for liver; 4 M 4 F for heart and skeletal muscle (SKM)). Darker blue indicates a more reduced state of the cysteine sites in TG compared to WT. b–e Representative traces of mitochondrial Ca²⁺ uptake responding to 20 μM Ca²⁺ in heart or liver mitochondria isolated from TG or cKO or hKO mice and their respective control mice. Ru360, MCU inhibitor; FCCP, uncoupler of oxidative phosphorylation. In d and e, enlarged view of the boxed regions are shown to the right. AU, arbitrary units. s, second. f Averaged data of mitochondrial Ca²⁺ uptake rate (1/τ, where τ is the respective time constant of extra-mitochondrial Ca²⁺ decay). Data are mean ± s.e.m. For heart mitochondria, n = 3 measurements from 3 WT mice, n = 4 measurements from 3 TG mice, n = 12 measurements from 5 Control mice, n = 4 measurements from 4 cKO mice; for liver mitochondria, n = 6 measurements from 3 WT mice, n = 6 measurements from 3 TG mice, n = 4 measurements from 4 Control mice, n = 3 measurements from 3 hKO mice. 3-month-old male mice were used. In f, two-tailed unpaired Student’s t-test with Welch’s correction was used. *p < 0.05, **p < 0.01. Source data are provided as a Source Data file.