FIGURE 4.

Acetylation of K‐1479‐ Na_V1.5 in mitochondrial complex I‐deficient cells decrease sodium current. (A) Western blot for Na_V1.5 protein in 293 cells lacking Ndufs4 (Ndufs4 KO) or Ndufs2 (Ndufs2 KO) which were transfected with plasmid carrying WT or mutant Scn5a gene (to produce WT or acetylation‐site mutant Na_V1.5 proteins). (B) pH of conditioned‐media from 293, Ndufs4 KO, and Ndufs2 KO cells at 24 or 48 h after plating (n = 6/group). (C) Live staining of 293 (WT), Ndufs4 KO, and Ndufs2 KO cells with markers of mitochondrial membrane potential (TMRE), total cellular ROS (DCFDA) and Hoechst (blue). (D) Representative fluorescence images of acetylation of Na_V1.5 residue K1479. (E) Quantitation of results in panel C (n = 5–10/group). (F) Quantitation of results in (D). (n = 4–12/group). (G) Patch clamp results of I _Na for WT and Ndufs2 KO cells with or without NR treatment. Quantitation of (H) relative I _Na density at −20 mV and (I) AUC for the indicated groups in panel (G). n = 7–19. Data are mean ± s.e.m. of biologically independent samples. Statistical significance was determined by ANOVA and post‐hoc analyses. *p < .05, **p < .01, ns not significant