LARP4 is an RNA-binding protein that binds nuclear-encoded mitochondrial mRNAs to promote mitochondrial function

Loss of LARP4 reduces cell proliferation rates, levels of oxidized proteins, and protein translation rates. (A) Summary plot of average confluency doubling times for WT HEK293 cells, HEK293^LARP4−/− KO cells, and HEK293^LARP4−/− KO-Rescue cells from independent experiments. N = 3. (B) Plot of cell doubling times of WT U2OS cells and U2OS^LARP4−/− KO cells, averages of technical replicates (n = 6–14) from each of two independent experiments are shown (Rep 1 and Rep 2). (C,D) Analysis of oxidized protein abundance by the OxyBlot assay (C) and quantification of normalized oxidized protein signal averages (N = 4) for each cell line, each replicate represents an independent experiment (D). (E,F) Analysis of translation rates by the puromycin incorporation assay (E) and quantification of normalized puromycin incorporation signal averages (N = 3) for each cell line, each replicate represents an independent experiment (F). Statistical significance of differences was assessed by two-tailed unpaired Student's t-tests (*) P ≤ 0.05, (***) P ≤ 0.0001. (N.S.) Not significant. See also Supplemental Figure S3.